Pocket size Espresso Machine with integrated alcohol stove.

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I’ve always been fascinated by small things. I remember going to the mall as a kid and seeing all the Hello Kitty mini stuff at Spencers, and being really disappointed that they only made girl stuff (it was years later before they came out with boy stuff)
So, when the Pocket Size contest was announced, it really inspired me to design and build something new.

“Mmmmm Ok, now what?” I said to myself.

So I started browsing Instructables, trying to find some inspiration when I remembered that the year before, my Espresso machine had died, and I had played around with the idea of building one.

I looked at all the Instructables relating to coffee at the time, but no one had built a machine. The quest ended that Christmas with the gift from my wife – a new espresso machine (I know, she’s really great :D ).

This year, a quick search showed that there were still no Instructables on how to build an Espresso machine….and inspiration came: I would build a pocket sized Espresso Machine.

Now, I’m going to stray a bit from the normal Instructable format and include two sections: Design and Build.

One reason to do this is because I’ve noticed a number of kids on the site, and maybe, just maybe, reading about the design process might inspire them to build great stuff.

Another is that, because it had to be pocket size, I took some decisions that may seem odd, and telling you how I got there will help you modify this project more easily to better meet your coffee needs (like making it bigger).

Also, as it turned out, the alcohol stove that came out of this is a rather novel design, easily modified, that might breed a whole new class of alcohol stoves. :D
Three cheers to giving back to the community!!
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androida2 months ago

For my graduation final project I will be developing a way to make coffee out home. Here in Brasil there are no stuff such as handpresso and mypressi (they are expensive too!). I have been searching many similar products and ideas and your project inspired me in every bit of its process. You are awesome! Thank you!

urant (author)  androida2 months ago
You just made my day!

While your still looking for ideas to inspire you, take a look at my other project:
It's a "more handpresso" type machine.
Look it over, I have no doubts that you will find ways to improve the design, substitute parts that you can source locally and end up with a GREAT final project.

Best of luck !

(if you can, share pictures of you creation, or better yet, you're own Instructable)
androida urant2 months ago

I looked at it. You redesigned to improve the issues of your first machine. Amazing project!
I will talk to my teachers about this idea to make my project open (I am waiting for the right moment...). I will let you know about it ;)

Thanks for the suport!

urant (author)  androida2 months ago

Anything I can do to help you out, just ask!

I agree wholly with kaeldra, a video of this device in action would be fantastic, I'm considering using this to make an art piece that will in theory make you a cup of coffee as well, and as this is diy and leaves room for spatial modification, it's perfect. Keep up the great work and please please please try to post a video

kaeldra10 months ago
I'd love it if you uploaded a video showing this in use! From the start of fueling and filling to the finished cup of espresso if possible. This is really neat! Beyond my current abilities I fear (never have soldered anything as of yet) but maybe something I could attempt in the future! Plus you are right it did give me ideas for more projects! (which are also out of my league but maybe someday!) :-)
InTheory1 year ago
That is insane I need to make something half this cool.
urant (author)  InTheory1 year ago
Yes, my wife also thinks i'm a bit insane :P
InTheory urant1 year ago
Sir, you are a genuis.
Geli121 year ago
I LOVE your introduction!
I adore miniaturized things, too :D
urant (author)  Geli121 year ago
Thank you very much!
OliverBoy2 years ago

This is a fantastic instructable and I am looking forward to making it.

I live in the UK and we use the Metric system for measurements. It seems that we don't have matching plumbing fittings, our fittings are a little bit smaller.

Given how concise this project is in the original design I was wondering if you think I will come across problems making the more intricate parts (stove).


PS are there any videos out there showing the construction of this, that would be more than useful! haha
urant (author)  OliverBoy2 years ago
Hi Oliverboy!

No, I don't think you will have any trouble "translating" to metric. Just get the nearest sized fitting that you can.

Sorry, I didn't film the making process.

Tell me if you need any help on the way, and may be you can make a metric version of this instructable :D

good luck!
Man.. no problem about being copper made.. if there is no scratch the copper, it would not harm anyone. BUUUT... a friend of mine that is a chemical engeenier alerted that the solder can and will release toxins on heating.. on high levels. Theres no solder that is not toxic. So, that is the only flaw on your project. Anyway its a cool design, ill be looking foward to a non-toxic design.
-sighs and shakes head sadly- it makes me wonder how many MORE people will spout this ignorant crap. -clears throat- ELECTRICAL SOLDER IS TOXIC! PLUMBING SOLDER IS NOT TOXIC! USE PLUMBING SOLDER!

if it was so "toxic" do you think the building codes would allow it to be used in your home? that would be a resounding HE** NO!

(from step 4)
Some makers have commented on two possible problems they see with the build:
1) Lead in the solder
2) The use of copper and food.

The first is very easy to address: JUST USE LEAD FREE SOLDER*.

*caps done by me

btw copper is ALSO not toxic. i have no idea where people come up with these crackpot ideas. even if it WAS toxic, the absence of scratches wouldnt matter since the properties of the metal would leach into the hot liquid an'way through the rest of the surface.

besides, if it was so "toxic" you honestly think they'd allow it to be used as residential water lines? THINK ABOUT IT! you my friend need to do more research.

if you're looking for a "non toxic" design, according to your thoughts, you'd have to make it from food grade stainless and fusion weld the damn thing together with TIG. to make one with his design constraints? you might as well forget it existed.
acoleman is not exactly right about most of this post.

He's right enough that his info is not likely to get anyone killed but wrong enough to warrant a gentle correction. I'm not trying to be a tool, but there is some important corrections here.

"Just use lead free solder" ... Like plumbing solder? Except most plumbing solder contains antimony, or copper, or cadmium, which are are all toxic when in contact with food. When a soft solder says 'silver' it actually means 'silver-bearing' which means that most of it is tin and antimony, and copper.

"if it was so "toxic" you honestly think they'd allow it to be used as residential water lines?" ... This can get a little technical, bear with me. What is the ph of drinking water? It's near 7, neutral. So materials like lead, copper, cadmium, antimony, etc. which produce toxins as a reaction to acidity (or lack of) do not pose any real threat when used in residential water supply lines.

The issue of copper in particular is covered in Chapter 4 of the 2005 FDA Food Code with further explanation found in Chapter 3 of the 2005 FDA Food Code Annex.

Coffee, if you are doing it right, is acidic. Everything from where the water touches the grounds onward should be some other material. Many old houses have lead water pipes. Many water mains are cast lead pipe. Lead poisoning from these sources is practically unheard of. Really they didn't need to ban lead  plumbing solder but... meh. Nevertheless, I wouldn't serve lemonade out of a lead pitcher.

I hate to point out a flaw without offering a solution.

Get a stainless filter from an old portafilter or mokka pot or whatever. Or make it per instructions but use stainless steal from the bottom of a sapporo can.

Then tin the inside of the brewing chamber. Get 100% tin from a HVAC shop and a suitable acid flux heat the thing up and lay it in. Nice, neat, food safe.

Solder with a nice food-safe soft solder. I like SoldaMoll 220 by brazetek. It flows great and if you got bucks to spare you can tin you brew pot with it so it will look prettier. Also it will wet and flow much nicer than plumber's solder.
Dec 28, 2011. 3:00 PM
acoleman3 says:
It's near 7, neutral. So materials like lead, copper, cadmium, antimony, etc. which produce toxins as a reaction to acidity (or lack of) do not pose any real threat when used in residential water supply lines.

get a grip....the coffee is in one small portion. the rest of it is dedicated to fuel and guess to guess? thats right....WA-TER! which as you say, is only ph 7. that blows your comment about how dangerous it is. the brew chamber is small as well as the exposure time for the acidity of the coffee that the amount of copper you would be ingesting is minuscule.

not only that....but you need to do more research on copper itself. what is dangerous is cupric sulfate (copper II)....not the element copper. copper is used as a health supplement, don't you know that? besides, according to the fda, you can ingest 1.3 mg/L a day and be safe. im pretty sure what you get from this coffee maker is far below that.

plumbing solder does not contain lead and the amount of antimony is small. so much so that it does not pose a health hazard. you can, according to the fda, ingest .006 mg/L a day and be ok. im pretty sure what solder the coffee encounters leaches amounts way below that.

if you look at his will see on item 2:

The product had to be made out with common, cheap and easily obtainable materials from any home improvement store or corner hardware store. (sure as hell not from an hvac shop or your soldamoll 220 since it's not sold at your local diy....such as lowes and home depot)

not to mention in the front page he specifically says a maximum budget of $30. im sure your ideas blow way past that figure since you said "if" when talking about tinning the coffee chamber. im also sure since your solder isn't sold in your local diy, its gonna be more of an expense in itself then general plumbing solder.

"if you got the bucks to spare"
that blows you tinning idea right there since its out of the financial ability of most people, especially teenagers who have to live on a budget and who's parents im pretty sure are NOT going to fork out the money to have such a small item treated in this way.

you have an idea for a better way? great...make your own instructable for those who can afford to get such things as you've mentioned.

think in a practical manner, according to his instructable, and wake up to reality.
Kage-- Relax. I'm sorry, but on so many parts of this you're just wrong.

I said at the beginning this espresso machine is a great build, but some of the concerns about the use of copper and plumbing solder are warranted. Specifically, from the point where the water meets the coffee grounds. You seem to be taking it personally. Instead of asking informed questions and offering constructive criticism, you are lashing out at one who is doing just that.

I need to do more research on copper? I'm supposing that you think that elemental copper is not dangerous because some wikipedia article tells you that it is copper (cupric) sulfate that is the toxin. Follow me on this. Copper reacts with acids to form copper sulfate. Acids in coffee, acids in your stomach. That is why it is safe to use copper for drinking water and unsafe for many food applications ... like coffee.

Your argument that copper is safe is ridiculous. I say this with love but I'm sorry, it is. Copper is so safe that the FDA (an authority you cite) BANS its use where it may come into contact with acidic foods ... like coffee. There are safe doses of lots of toxic things. But if someone published a cookie recipe that included a milliliter of gasoline I would be inclined to offer a few alternative ingredients. No one ever got sick from ingesting 1/12th a  milliliter of gasoline (recipe yields a dozen) so there should be no problem. Common sense revolts at such an idea.

"Copper is so safe because you can buy a copper supplement...(para.)". You can buy a lot of unsafe things; guns, cigarettes, marriage licenses. Try and buy copper supplements. What follows is the warning that comes up when I tried (emphasis added):

"WARNING: WARNING! This nutritional supplement,contains COPPER, a potentially TOXIC mineral. Do not take more than 4 mg of elemental copper per day. Accurate measurement requires the use of an analytical milligram scale! If you do not have the analytical skills necessary DO NOT USE THIS PRODUCT! Improper use may require emergency medical treatment! Seek medical care for accidental use. The only safe way to measure this product for individual use is by using a milligram weight scale that is accurate and precise to 1/1000th of a gram, or 0.001 grams. PureBulk offers many scales of various accuracy and precision."

If you want to play Russian roulette with heavy metal and copper poisoning then great. But people should know that there's a risk involved that really doesn't need to be there. There is certainly no functional benefit that comes from building this project in ways that expose its user to these toxins.

You seem concerned on the grounds that a teenager might not have the kind of cash (or sympathetic parents) to build this project the way I suggest. This is a dangerous mindset. It leads to cutting corners. The easiest, cheapest, and fastest way to do something is always: right the first time.

You know what would put you way over the $30 budget? A trip to the ER because after a long camping trip you wake up one morning with blurry vision and the runs.

There's easy ways to play the game safe that don't violate the maker's self-imposed constrictions. I gave a few suggestions and when I say "If you got the bucks to spare" I'm talking about 2 or 3 of them. Using stainless steel for the filter mesh will save the cost of a copper slip coupling (about $2). So there ya go.

Tin the brewing head with tin ingot.
Tin ingot is cheap, but can be a little tricky to find. It can be ordered online or from an HVAC shop.

Tin the brewing head with silver solder.
I like SoldaMoll 220 but Harris' Stay-Brite is easier to get. Home-Depot carries it. It's more expensive than Plumber's solder but for the quantity used it doesn't represent a significan increase in the budget. And, using it to join the rest of the project will have an aesthetic advantage.

Use a stainless steal pipe for the brewing head.
a short bit of stainless is easy to find for a resourcefull maker. It will need to be hard soldered (brazed) to the copper but the same propane torch will do the job and a small job pack of safety-45 silver solder is not cost prohibitive either.

Here's another:
Electroplate the inside of the brew head with nickel or chrome or gold.
The kind of fun stuff a maker would enjoy doing. A primative plating set-up is not expensive.
What kind of acids are we talking about here? Unless it is sulfuric acid, you need a source of sulfur to make a sulfate. Copper, while commonly used in sauce pans is recommended to be coated in a less reactive metal (as you say). Tinning is a good idea. I think at also goes without saying to not skimp on the right solder since that sounds like it will be the major source of troubles.

As to other leeching, is the heat plus acidity where any of the issues come from because there are many substances where they are inert at room temp but react when heated sufficiently. ("proper" solder assumed)

To any other readers who took the care to browse the comments. Regardless of what you take from this discussion of toxic metals, I would not advise using this for a daily espresso maker unless you have the ability to have testing done on the amount of metal leaching to know if it is safe, "safe enough" or down right dangerous.
Fair enough, I was speaking rather basically about the nature of copper and other reactive metals. And also, for the life of me, I was sure sulfuric acid was one of the acids present in coffee and gastric acid. Its not.

The point is academic. Coffee contains Citric Acid which combines with elemental copper to form the poisonous salt copper citrate (a pesticide). It contains malic acid which reacts with copper to form copper malate.

The point being, that even if elemental copper itself is not toxic (a point I would not make) it will react with many of the 30+ acids found in coffee to create salts which are toxic.

The point being, that copper poisoning is not a joke. Heavy metal poisoning (lead, cadmium, antimony(?)) is not a joke. And just because drinking water might be able to flow safely through these materials does not mean they are safe for preparing food.

I'm a little shocked at the backlash at my suggestion of some ways to mitigate a great deal of this risk. Looking through the list of symptoms for copper toxicity, I'm sure there must be something in there that would make a little extra effort worthwhile. For me it is either the possibility of blindness or 'tarry black feces'.

my comments not showing up all the time is beginning to piss me of.....but an'way. i love how you've thrown common sense right out the window here. the surface aria of the brew chamber is about 5 sq inches with an exposure time of about 40 seconds. do you honestly think you are going to get your 4mg of copper out of that? besides.....the figure *i* gave you was *way* smaller then that. does 1.3 mg/l remind you of an'thing? so you just proved that the body can take in even *more* then the fda limits.

according to they say it's 1.5 mg and point out how rare copper toxicity really is. you have to have an intake of 10mg a day for over a few weeks before you start getting into the horror you're trying to push on us. i also said the antimony limit is .006. now considering there is less then .75 sq inches of solder exposure in the brew chamber.....well....again youve thrown common sense out the window.

where's your chemical analysis on this, you tell many mg/l of copper is really in this coffee and how much are you gonna get poisoned by drinking even 2 shots a day. according to your proof, since you can ingest 4mg a day, your argument is irrelevant since an acid as weak as coffee is not going to strip away that much copper and im pretty damn sure i'ts *not* going to contain 10mg/oz..

yeah....way to go on equating health.....yes HEALTH supplements with tobacco and guns. that was a rather idiot statement and an irrelevant comparison. especially since pretty much all multivitamins contain high concentrates of copper. what....shall we ban those because they're so "toxic"? OH GOD THEY CONTAIN HIGH AMOUNTS OF COPPER! THROW THEM AWAY QUICK!. give me a break. if you have proper zinc intake, at a 1:8 in favor of zinc, the copper in the body *will* be kept in check. not just zinc but manganese, caffeine, selenium, iron, b-6, folaic acid, vitamin c and sulfur as well.

what causes copper toxicity in the first place is the lack of binding to ceruloplasmin and metallothioneine. two proteins that transport it to the mitochondria where it can be broken down for cellular fuel. after all, copper toxicity is coupled directly with copper deficiency.

sorry, try again
Just use sliver solder, it is used on many sufaces in drinking flasks and tankards that solder is the best due to its resitance. Just a thought!
You ask how much copper will leach into the espresso that comes in contact with 5 sq in for 40 seconds. I don't know. Do you? What method do you use to determine this?

You point out that drinking water can contain up to 1.3 mg of copper per liter. How much do you drink per day? Water, soft drinks, etc? About 2 liters per day is average so for all you know you are getting two and a half mg of copper a day just from what you drink.

And as your Russian herbal medicine website explains, copper is present in many foods. It's highly concentrated in some foods.

How confidently can you claim to know what your average daily intake of copper is before you add something like a bare copper coffee pot?

Will you remember to warn every guest you serve a shot of espresso to that the coffee was prepared in a bare copper pot? Some people have severe reactions to even small levels of copper.

This is what common sense is. It is making a rational decision. Risks must be balanced by reward. Big risks require a big reward to make them worthwhile. Little risks, likewise, may be justified by little rewards.

You have acknowledged that the risk of using this item as described is greater than zero. You and I may disagree over how much more than zero it is but that's not the point.

So what is the reward of building it this way? I've shown that a few changes in materials and you can build the same thing, using the same tools, for the same money. Well within the constrictions listed.

So what is the benefit that you get out of raising your exposure to copper toxicity (even by just a tiny amount)?
I'm hoping I did not sound like backlash with how I presented my response.

Food-safe or not can be a big deal for homemade projects.

I was bothered by the seeming: "you're wrong," "no, you're wrong" argument I saw unfolding.

I had some additional questions I though could fill some gaps. It's great if we do some research and decide for ourselves, but this is a big issue the community needs to know about too.

Everything else aside, it seems this can still be a wonderful portable boiler, short some of the modifications you mentioned.
After some further research (including talking with a materials science engineering professor at my University, it sounds like there may be some value in determining the corrosion rates for copper exposed to an espresso mixture (the details of running such tests were left out of the recent discussion pending further research pertaining to EPA standards for copper contamination).

Speculative assessment (given this is NOT his specific field of study, but his background knowledge of material chemistry) puts expected leaching quantities for the physical scale of this project in the nanogram order.

Additionally, one of the hard facts he did provide was that unless we are getting different reactions from the acids, (which are themselves edible) that are creating compounds that are not salts (since a salt is ironically bonded, learn some chem. for implications) the anion does not matter. The salt is a copper delivery system, not a unique toxin.

Furthermore, being a metal used in bodily function, you do have means of clearing Cu out of your system when levels are in the manageable range.

Water leaching standards are based on the assumption that you are already consuming average amounts of copper containing foods and drinking average quantities of water. So rather than copper being toxic if you ingest >1.3mg Cu diluted into 1 L of water, the maximum contaminant level also assumes that is your average liter of water, not a single given liter of water.

My opinion as an informed researcher, not an expert, is that this should not be an item for daily use, but given proper cleaning/maintenance is safe for making espresso.

@cobright, thank you for your concern. I hope this helps.
"it sounds like there may be some value in determining the corrosion rates for copper exposed to an espresso mixture"...

I've been stuck at this point myself. Here's what I did:

I built a porta-filter out of copper that would mate with my espresso machine.

With the stainless steel filter I ran 40 shots of distilled and tap water through using a plug to slow the water down through the filter-head (it's used for cleaning the unit). I drew off one liter from each and called them samples A and B. I tested both samples with a test strip that reads positive at >=0, .3, .7, 1.0, and 1.6 mcg/liter. Neither sample tested positive at any level.

Then I did the same with the copper filter head. Samples 1 and 2. Neither sample tested positive at any level.

Then I tested both systems using tap water from my brother's place (a different water system): Samples C and 3. C tested positive at > 0 and 3 tested positive at >.3.

Conclusion so far... I have great tap water, distilled water has no copper in it, My brother's tap water not only contains copper but is acidic enough to absorb some copper out of a copper espresso brew head. I suspect his water was just under the threshold for the higher result and actually absorbed a very tiny amt. but enough to change the result in a sample size that large is significant.

Then I brewed 20 shots of a three different types of coffee using distilled water. Samples I, II, and III in the stainess and Ic, IIc, and IIIc in the copper filterhead. I passed the results through a ceramic filter to remove particulates that tinted the test strip. Samples from the stainless system did not test positive at any level. Samples from the copper system tested >0, >.3 and >.3 respectively.

Any sample brewed through coffee in the copper head, when dried on filter paper and burnt produced a green flame.

That is the end of my diagnostic capacity. I don't have access to atomic machines anymore and it is little more than a corollary interest to begin with.

As I said at the very beginning, I'm not terribly worried about this build making anyone sick. But the distribution of bad information by ill-informed and self-proclaimed authorities could do much worse.

When someone tells you that copper is not toxic, they are wrong. Like most toxins there is a level of intake below which you will not suffer from copper toxicity.  An WHO report on the subject found a significant portion of the population will experience harmful effects at levels as low as 3mg in a day. Considering that you might already be taking in this amount from your normal diet and drinking water, I would say that steps to avoid additional exposure are reasonable.

If you know with a certainty how much copper you are taking in presently and exactly  how much copper using this device will add to that and exactly how much copper you excrete a day ate every level of intake, then you could reasonably calculate your risk of copper poisoning. All of these are dependent on a multitude of  variables, none being easy for the average person to measure.

Further, there is the concept of 'best practices'. When you settle for second best once, it becomes easy to do it as a matter of practice. I do it all the time when best practice adds no value to my build. A high-gloss finish on metal adds no value to me so I rarely expend the resources to do it.

But putting that finish on a project takes a lot of extra time, effort, even money, and I get nothing I value out of that investment.

Building this espresso maker in a way that mitigates all or most of the exposure to copper poisoning and heavy metal contamination does not add to the time, effort, or cost of this build. If you can reduce a risk under these conditions you probably should. Unless you just like risk. In which case I recommend taking up skiing. If skeeing goes badly people will love to hear your story about a broken leg. If you get too much copper, no one will let you tell them about your sticky black BMs and accompanying stomach cramps.
apperenty my reply didn't post so i had to do it this way.
As far as i know the solder plumbers use is silver solder,and needs oxy acetaline,ie very high heat.
Some old houses still run lead pipes ,and copper ,with lead tin solder.
I get that heat will release toxins from the solder. I just doubt that this gets that hot. When I make one I will know for sure. However, I do know that there are copper pipes that have been soldered coming out of my hot water heater and I seen to still be alive even though I have ingested a decent amount of it.
vreme2 years ago
I have used an electric stove for soldering copper parts (cpu water block) with good results. The only drawback is that it heats all the copper parts at the same time, so you have to secure them in place somehow.
After some further research (including talking with a materials science engineering professor at my University, it sounds like there may be some value in determining the corrosion rates for copper exposed to an espresso mixture (the details of running such tests were left out of the recent discussion pending further research pertaining to EPA standards for copper contamination).

Speculative assessment (given this is NOT his specific field of study, but his background knowledge of material chemistry) puts expected leaching quantities for the physical scale of this project in the nanogram order.

Additionally, one of the hard facts he did provide was that unless we are getting different reactions from the acids, (which are themselves edible) that are creating compounds that are not salts (since a salt is ironically bonded, learn some chem. for implications) the anion does not matter. The salt is a copper delivery system, not a unique toxin.

Furthermore, being a metal used in bodily function, you do have means of clearing Cu out of your system when levels are in the manageable range.

Water leaching standards are based on the assumption that you are already consuming average amounts of copper containing foods and drinking average quantities of water. So rather than copper being toxic if you ingest >1.3mg Cu diluted into 1 L of water, the maximum contaminant level also assumes that is your average liter of water, not a single given liter of water.

My opinion as an informed researcher, not an expert, is that this should not be an item for daily use, but given proper cleaning/maintenance is safe for making espresso.

@cobright, thank you for your concern. I hope this helps.
TwistedJack2 years ago
This is fantasic, cant wait to make it. only thing i wish i couyld take it to school and show it off, but no lighters or fire preducing things.
You sir are a genius. I can't wait to make this but mine will probably end up making an alcohol fuelled pipe bomb! thank you for making this instructable!
I'm sorry that I upset you. I'm not saying that to be flip or imply that you are emotional; it truly was not my intention to be offensive. I try to say only things I am certain to be true and which can be supported by credible sources if challenged. When I am shown to have said something in error, I correct it and thank the person who does so. It is my nature to speak boldly as Keynes said, "Words ought to be a little wild for they are the assaults of thought on the unthinking."

Please remember that I entered this conversation after you (or acoleman3 if he is not you) made factual statements about the safety of a material used in this instructable. Namely, that the materials used in plumber's solder is not toxic and that copper is not toxic. I think everyone would agree that these types of remarks are exactly the kind of statements that should be scrutinized.

Statements which, rather aggressively, berated the concerns over the safety of these materials raised by fellow members. " many MORE people will spout this ignorant crap..."

Several of these factual assertions and resulting conclusions were, in fact, unequivocally wrong. It is not my fault that they are wrong. If the error was about a matter of low consequence instead of about the safety of mixing copper and food I would have ignored them out of politeness.

My post was polite and every statement of fact in it is verifiable. Copper and other metals used in many plumber's solders (even those labeled 'silver solder') are in fact toxic and unsafe for use in food preparation. This is not my opinion, it is the judgement of the FDA. If someone chooses to be less cautious than the FDA then that is fine too, but facts are facts.

Quick question: do you tamp the coffee down at all? if so, how do you do it with the screw in the middle?
urant (author)  bobiffer01232 years ago
No tamp is needed
kfifield3 years ago
I am having a lot of trouble getting the stove to light. any tips? I feel like the alcohol isn't vaporizing and is just coming out the bottom where the screw goes through.
urant (author)  kfifield2 years ago
When that happened to me, it was because to much fuel was getting into the stove. If you are using the syringe, paste a piece of tape to the open end of the syringe and poke a single hole into it with a needle. This will slow the flow rate of the fuel getting into you stove and should have the small volume necessary to evaporate the fuel.
Tell me how it goes
spdrcr10103 years ago
I saw your instructions and couldn't resist! It took me about 3 days to source parts and build. I did something a little different in the brew head by soldering a ring below the water inlet to sandwich an o-ring between the cap and reducer. Also instead of a syringe I just used some very small copper tube to meter the fuel. I might need to change that tho because the tank can get warm and start vaporizing the fuel in the tank making a larger than desired open fire.
Made some tasty black beverage tho. Cheers!
I'm having a hard time finding these:
1 1 to 1/2" reducer (the type that fits into a 1" tube) for the brew head
1 1 to 1/2" reducer (the type that fits over the 1" tube) for the boiler

I found one type, but not sure which one because I don't actually have any 1" copper pipe to test :-/
when you go to the hardware store just dry fit it into a piece of 1" copper pipe on the rack.
acoleman33 years ago
would it help to angle the preheat tube up like...3/16 in to help the fuel flow into the combustion chamber better?
urant (author)  acoleman33 years ago
Not really, since the fuel never flows in the stove. The moment it leaves the syringe and hits the tube, it vaporizes. As a mater of fact, the stove "ticks"; you can here the fuel hit the inner tube and vaporize.
tdshelton3 years ago
I'm really enjoying building this coffee maker, and was hoping you could clarify one point -- the syringe.

What exactly is a #10 syringe? Is that a regional description, or the way a particular manufacturer labels their syringes? Searches both in local pharmacies and online for a "#10 syringe" yield nothing.

If anyone has a link to a syringe that's appropriate for this 'ible, I would really appreciate it. Otherwise, advice on brand, syringe capacity (ccs? ml?), and needle gauge would be helpful, too.

urant (author)  tdshelton3 years ago

That's what the guy in the pharmacy called it. It's the next to biggest size they sell.
As a fiscal reference, it's diameter is 1/2"
BTW, the needle came with it
What's a "Number 10" syringe? I can't seem to find one on the internet...

or maybe I'm just bad at searching.
CurtR3 years ago
I'm just wondering what the volume of a #10 syringe is, nobody at any of the pharmacies around here has any idea.
in the first picture here, there is a fitting with a hole in the top. Is this the 1" to 1/2" reducer that fits OVER the 1" pipe, or is that a 1" cap with a hole drilled in it?

This instructable is really great, but I find that there are fundamental issues with some of the steps provided.

I want to build this for camping, but I don't want to waste a bunch of copper fittings either. That stuff is expensive these days :(
If you mean the whole in the bottom of the completed unit above in the pic in the intro I do believe yes. That is the boiler component.
Godfavored3 years ago
Hey I'm new to soldering copper pipe, Im a pretty good welder and do some electronic soldering but never done this before, im using a little blow torch from home depot but I'm having a problem getting the thing to actually seal... Any tips? It seems like by the time the solder starts to stick to the pipe it's too hot and it just runs down the pipe... Maybe I'm just heating it up too much?
not sure how much you know about this so im just gonna start from the beginning.....forgive me if i cover what you already know.

take 180 grit paper and shine the outside of the pipe and the inside of the fitting
clean off both parts with a rag and apply flux paste
assemble the pieces and heat them up until they start to darken
keep your torch flame on the connector and apply the solder to the pipe near the joint.
if everything has gone well, the joint will suck up the molten solder. once that happens, take the solder and torch away and let it cool.

my guess is that you havn't properly prepped the pipe and fitting. if there is any copper oxide present, the joint wont take the solder. also, like i said, you need to heat up the connector since solder flows to the heat. then again.....are you using plumbing solder? its specifically designed for this.

if there's any of this you're already doing, let me know so we can get to the answer better.
Izher3 years ago
so I think I'm going to make mine zippo powered o_O what do you guys think.
acoleman3 Izher3 years ago
i dont think it would get hot enough.
JKPieGuy3 years ago
Hey can you please make a video of it working? I found this very cool and was even thinking about making one so I wanted to see how it worked.
god.favored3 years ago
Absolutely Love it, im almost done with mine now:) just cant find a 6-32 screw thats 3 inches long:( closest i can find at my home depot is a 3" thats a number 10 and it just seems a bit big... guess ill have to go to lows...
photo (4).JPG
Doddity3 years ago
Doing Design and Technology at school this and next year, (only 2 days till schools out here in Australia). This will be a great help in my portfolio, thanks for the explanations.
jonnyboy3233 years ago
Finally got a chance to finish today!
Made a just a few modifications and included pictures :)
1. Put a filter in the bottom of the brew head that I found in the pluming section.
2. Added a little handle to the water filling screw
3. I left the pipe entering the brew head long, then drilled a few small holes in the sides so that the water gets dispersed evenly over the coffee grounds as it comes out.
So awesome. A lot of work but well worth it! And of course thanks for the help along the way!
urant (author)  jonnyboy3233 years ago
How was the Espresso?
How long did it take to brew?
Haha thanks!
Actually this was just a test with some really strong coffee from my Keurig called Jet Fuel. I still have to go to the store to buy some real Espresso :)
To be honest I don't know how long it took. I will have to time it next time. But I'd say your estimate of 3 min is about right. I sometimes have trouble lighting it, but I found that I can remove the fuel tank and use a small syringe to inject fuel straight into the vaporizer tube through the fuel dripping hole. (I did not solder the fuel tank to the inverted cap so it is removable!)
The only two issues I have now are that I need a large syringe or something to fill it with water completely, and I never found the large gaskets for the brew head. My o-rings work, but seem to leak a bit. Even after my mod to the tube entering the brew head.
But other than that it is awesome and everyone I have showed has been very impressed with your design. I have even had a request to make another one for a friend's father who enjoys coffee while camping!
Oh and a little tip I saw somewhere (probably instructables!), I have been using 5 hour energy bottles to store the fuel which seem to be the perfect size.
urant (author)  jonnyboy3233 years ago
Before you now it, you'll be a small scale espresso machine manufacture :D
EdgeCoffee3 years ago
What kind of PSI are you getting with this device? A standard machine will produce around 7-10 PSI in the group. From the pictures it looks like your pressure might not be as high as this since you're lacking crema on the top of the shot (or your coffee could've been sitting for a while.) This is a really cool little machine, your next project should be a tiny steam unit to have on the go lattes.
urant (author)  EdgeCoffee3 years ago
Hi EdgeCoffee,

It's the same as a Moka pot, which is between 1-2 PSI
My next project will be a piston driven, fuzzy logic controlled Espresso Machine :D
stumpster3 years ago
I scaled one up to 4 oz size, using 1 1/2" pipe fittings, not quite finished as yet, but I found that, with a bit of tweeking, a tea light will fit in the bottom, and will test it to see if it generates enough heat to brew coffee... I'll post pics if and when I get the chance to finish and test it.
Izher3 years ago
You are AMAZING!!!! this is the COOLEST thing ever. I'm making one.

thank you
urant (author) 3 years ago
I came across a pic of an old camping stove that came in a square box...which got me thinking.
Should I take the stove out of the espresso maker, and get it into an Altoids tin and make a kind of general use mixed fuel mini stove?
That way, anyone can place a bialetti moka pot on it or cook a small meal.
Would anyone be interested in the design and Instructable?
plaverick3 years ago
this would be aperfect companion to this:
urant (author)  plaverick3 years ago
I had a cheap plastic version of this as a kid, and yes, it would make a prefect companion
fireice2893 years ago
I clicked on this project on a whim, and I am very glad I did. I really love how you wrote the instructable and it is even better for the results. Glad to have seen this.
codongolev3 years ago
I'd recommend a butane blowtorch. it'll probably give you better joints, and ones can be found for extremely cheap online (dealextreme has some for around two dollars, if you're willing to wait around a while for shipping). I know you said you wanted to stay away from torches, but I wasn't sure if you just mean the huge propane ones.

I paid a little more and got a bit bigger one for ten dollars. I'm kind of wishing I'd have gone with the two dollar one, though; the igniter broke pretty easy. (I still use it, I just have to light it with an empty lighter's flint.)
urant (author)  codongolev3 years ago
Well, I kinda want to stay away from anything with a huge flame that will most likely get me burned :S
codongolev3 years ago
I think it would be worth it to mention lamp-style stoves (like with a wick and stuff). it wouldn't be integrated into the design, but I believe that it would be fairly easy to make a methanol lamp-type stove with a cap on it to prevent spills. I'll post one if I ever get around to making this (which is actually a pretty good possibility).
MrRedBeard3 years ago
Well friggin done!!! I love it.
jonnyboy3233 years ago
Awesome Instructable, can't wait to try it!

On that note however I have a few questions pertaining to the stove. Having built a few pop can stoves myself, I understand how they work. But I've read and re-read and looked at the drawing a few times and can't figure it out.

So my questions:
1. What is in the first picture in step 10 on the right? A cut 1/4" cap and coupler  Leading to question 2,
2. Is there a 1/4" cap on the end of the vapor tube where the syringe enters the tube or is it soldered closed? 
3. What makes up the stove top? is it the 1/2" coupler? If it is a coupler, how does the stove work? to me it seems like the only way the stove jets would work is if the stove was made of 2 1/2" caps with the jets poking out the tip under the diffuser..
5. And lastly, what is the diffuser made out of? It looks like a washer or something similar.

urant (author)  jonnyboy3233 years ago
Retake a look step 10, I put some new pics that I had in my Instructable library but I forgot to drag them to the pic window
Thank you for adding those. I'm actually very impressed with stove design. Its size is revolutionary. I think I would have gave up after 5 or so prototypes :) As others have said, I love the included design process and especially sticking to constraints!
urant (author)  jonnyboy3233 years ago
I would love to know about your results (and help if needed)
Well I was very close to finishing yesterday. The stove works after some trouble shooting. Turns out the syringe was dripping too fast, which flooded the stove, which ultimately started dripping flame balls on my workbench. To anyone doing this, definitely only use it outside, just in case. All that is left is the brew head. :)
urant (author)  jonnyboy3233 years ago
It's really great to know that you're building one for!
Did you get the syringe to give you 1 drop per second? If it's going to fast, you need to make the air intake hole smaller. One way to do it (it's just to give you the hole size) is to place a piece of tape over the hole. Then, with a pin, make 1 small hole and see how the flow rate goes. too little, make a second hole and repeat.
after you know the correct hole size, close up the hole in the cap you made with a bit of solder until it's to correct size.
Once you stove is correctly set up, you be able to hear it tic, as the drop of alcohol vaporizes as it hit the hot 1/4" tube
After some late night trouble shooting I think I finally got it. But It will for sure need a few more tweaks. Here is a pic of the stove running for the first time. I was so happy I just had to capture the moment :)
urant (author)  jonnyboy3233 years ago
And you were able to take a pic of the flame!
urant (author)  jonnyboy3233 years ago
Hi jonnyboy
Here goes the answers
1) its a 1" cap next to a cut 1/2"
2) It's just solder shut
3) I made the stove top out of a small cut circle of copper, actually it came out of a 1/2" coupler cut in half (you could use two 1/2" caps, but I couldn't cut them thin enough)
4) you skipped it :P
5) the diffuser is made out of the second copper disk (also out of the 1/2" coupler)

If you see both the blueprint and the drawing you can see that the 1/4" tube has 4 cuts made with the hacksaw that are 1/4" deep. So that means that 1/16 of the groves are "in the air" between the stove top and the diffuser. The rest of the groves are in the stove body.
So, alcohol vapor enters the groves in the stove and exit in 4 jests between the stove top and the diffuser
ahhhh thank you very much. That clears everything up. I knew there had to be something on top in order for the stove to make sense :) I think I'll give it a go tomorrow. Will definitely post my results. Thanks for the reply!
arcraven3 years ago
Hey, congrats on making Boing Boing. Ur famous!!
urant (author)  arcraven3 years ago
Thank you!
I don't know about the famous bit, but a least a lot of people will come over to Instructables and hopefully get inspired to start making things!
diy_bloke3 years ago
"Is that an espresso maker in your pocket or are you just enjoying yourself?"
Mae West could not have said it any better
onrust3 years ago
Man, that is cool on many levels.
fidgety23 years ago
Many many thanks you have provided me with the perfect Christmas gift for my father and brother
Thank you
urant (author)  fidgety23 years ago
You have just made my day!!!
tig13 years ago
Bear with me here
first off butt ugly construction, given the tools you used and the lack of soldering
skills you did an amazing job, I’m impressed, I have been working with a vast variety of metals for the last 30 years I can see the passion you put into this project, If you like working with projects as much as your article shows, I would suggest taking a welding course, T.I G. in particular it's a very precise type of welding that would bode well with your talent ,this project would be intense with Titanium,you could anodize it a multitude of colors, or even stainless steel, seriously dude check out.
Tungsten Inert Gas welding.
A fan
urant (author)  tig13 years ago
Hi tig1,

You know, I left the build kinda "rough" on purpose. Some Instructables are so incredible and the builds so beautiful, that they due kind of intimidate the novice maker.
In this case, I'm hoping some kid will say....."hey, that looks really easy and it'll make a nice present for my dad"
That would really rock.
On the T.I.G. side, I hope one day to be able to both afford a welling kit and have enough projects to justify the cost.
TIG would be very nice, but it's rather expensive (I know as I TIG weld every day...) as the material and argon are far from cheap. Titanium is a pain to weld if you have not gas lenses and pulse. TIG needs also a lot of training...
A simpler but not so cheap alternative is a stainless steel 304 brazed with a alimentary silver alloy. A jewelry oxy-mapp torch is far more affordable than a TIG welder. You can find all the fittings in SS similar as copper.
It's a small DIY project so Copper with a lead free soldering alloy is enough. Just a lighter hand for soldering and more "elbow oil" for polishing.
Kickstart703 years ago
You've made me wonder if my 110v coffee cup "warmer" from Radio Shack could provide a high enough temp to brew from. If so, I could make the espresso using that, deliver it to the cup, add sugar and water (my preference) and then put the cup on the warmer to heat and enjoy.
stib3 years ago
I really like the way you have detailed the process in a way that would apply to any sort of project. Great instructible!

One question: stove-top espresso machines (aka macchinette) have a little safety valve, to release excess pressure should the outlet get clogged. I have actually had occasions where I've ground the coffee too fine and tamped it too hard and it has gone off, and there is a scary amount of hot steam inside one.

I dare say that there's not enough energy in the amount of fuel in this to be a problem, but should it perhaps have one of these valves. I think you can get them at places that sell spare seals etc.
urant (author)  stib3 years ago
Hi stib.

Yes, I also was a bit worried about not having a safety valve. Since I couldn't get one a Home Depot nor Lowe's, I tested the boiler under worst case: I filled it with water and fuel, and blocked the brew head. Nothing happens because:
a) there is very little water in the boiler
b) there is not enough fuel to super heat the water
c) the copper is rather thick compared to diameter.

Having said all that, you could buy one and place it on your build, just to add to safty.
sweet instructable. hey you should copyright and sell some of these.

as for those of you who keep posting questions about copper and especially lead:

first off it is CLEARLY STATED to use LEAD FREE solder. how would lead free contain lead? the solder referred to here is oatey plumbers solder or similar. lead in solder for plumbing has been illegal since i think the 40s somewheres around than(drain pipes could however be lead far as i remember). it is SILVER BEARING and runs probobly 5-8 dollars a roll at home depot(maybee 10) its the SAME solder that your local plumber uses on your mains. it is thick so a higher wattage iron is needed and DO NOT use the same iron that youd use for electronics. start out with a fresh iron thats pb free ROHS compliant.

copper contamination? hello most of our plumbing IS copper but to those who are concerned: you could use stainless steel piping or aluminum like is in the standard coffee pot but it may add to the price. just dont overdo anything if using copper but the amount of "overdose" of copper is so miniscule i wouldnt worry much. if you use hot tap water and coffee pots do contain copper also(expensive expresso machines sure do) also gutting an old electric coffee parts and harvesting the tubing and inside metals could prove useful and also contributes to recycling:)

its a great instructable just use your own good judgement with the build and youll be good as gold:) i think i shall save a copy of this baby to try myself.
urant (author)  walkerman19803 years ago
Hi walkerman,

Thank you for your comments but I would never copyright the design, I really wanted to give something the the Instructable community that has given me a lot of ideas and a boatload of fun.
anabors3 years ago
Is that non lead solder?
Yes. The builder was very specific about that in the first steps of this project.
oscarfalcon3 years ago
Nice! awesome project.
jtimmaj3 years ago
If you can stick a piece of solid copper wire into the syringe needle before you cut it, it will help prevent crushing the tip closed.
jtimmaj3 years ago
You may want to try re-flowing the solder over a kitchen burner. Apply some extra flux over the ugly solder, reheat, cool, and clean.
dbell3 years ago
Outstanding idea and instructable!
You have done a remarkable job putting this all together...

I saw only one quibble, and might be wrong at that.
In building the Brew Head, your step:
"Drill a ½ in hole through both copper filters once in place (just to make sure they’re aligned.)"
Shouldn't that be a 1/8" hole, for the 6-32 screw?

Oh - and be sure to use lead-free solder! :{)
(As if it hadn't been stated 100 times in 135 comments!!)

Again, great job!

Ugly betsy3 years ago
IMPORTANT NOTICE Cooking with bare copper is potentially dangerous it is not the copper itself that is poisonous but the reaction formed between the copper and the acidity of the food any vessel or container used with the intention to store or to prepare food must be coated with a secondary non hazardous metal such as tin or stainless steel this secondary metal is applied in a very thin coating to the interior of the pot NEVER COOK WITH AN UNLINED POT NEVER STORE FOOD IN AN UNLINED CONTAINER
urant (author)  Ugly betsy3 years ago
Hi betsy,

I didn't know this. I went with the logic "if all my house's water mains are copper, and copper is still used and sold as water tubes, it's ok to use"
I have a copper bottom kettle that I bought at Target 4 years ago, took a quick look inside and the inside is copper all the way.
Could this be because there are different alloys of copper, some which are food grade?

You could always build one out of any other type of metal (maybe bronze) since your design constraints don't have to be as strict as mine
I didn't know about copper toxicity either and had to read up on it. When acidic foods are cooked or stored in bare copper vessels, it makes it easy for copper to get into the food and therefore into your body. When too much copper gets into your body at once, your body has trouble metabolizing it and it builds up.

Your drinking water going through copper pipes is safe.

Also, fortunately coffee is alkaline, not acidic. When people talk about the "acidity" of coffee it's a reference to the flavour profile, not chemical acidity.  The actual ph of coffee is usually around 5.0, I think (7.0 being neutral, anything above being technically acidic.)
Um, I hate to say this Theprojectmaker, but I think you might want to revise your understanding of the pH scale. Any figure below 7, such as pH 5, is acid. Alkaline is any value above 7.
Thetis urant3 years ago
I love your idea but I too first thought "ooer" when I saw it was soldered copper.

In the UK, water companies add buffers to acidic water supplies to avoid copper toxicity - I imagine it's the same elsewhere. Scale building up in the pipes will also help reduce the amount of copper dissolving. If you do have an acidic water supply, you probably shouldn't be using your copper kettle.

Bronze is an alloy, which is mostly.... copper, so probably not much better. The same goes for brass. Aluminium is very difficult to solder. Stainless steel would be best but isn't the easiest to work with either. Silver would be cool....!
urant (author)  Ugly betsy3 years ago
Do you think I should add the step "tin every inside surface"?
mercurey8733 years ago
First off I want to say this is the most impressive thing I have seen on this site and have never been so interested in starting a project. Can't wait until the morning gets here and I can get moving.

One slightly lazy question.

After reading through your guide, which is outstanding, I would greatly appreciate a parts list of some sort. Going through everything I know I could probably come up with a rough shopping list but if it wouldn't take you very long a short one in response to this would be awesome prior to me heading to Home Depot. Thanks so much and once again WELL DONE!
urant (author)  mercurey8733 years ago
Good idea,
Just added a Parts and tools list
Thanks for helping me improve this Instructable
Perfect, exactly what I was thinking and I already see a few things I left off my rough list. So happy to see this done before I woke up, fast response time means a ton, thanks bud. Keep up all the good work, cant wait to see your next project.
agis683 years ago
man its greate....but there's a big BUT!!! One of the biggest reasons roman empire failed was the cooking devices was copper made....think about it.....that's why in modern times they dress up the copper with another nonactive metal....they galvanized them....(at least they do here in Greece in some traditional cooking devices)
Hi Agis,

The theory of one of the causes of the Roman Empire fall was the widespread use of LEAD for pipes, for tinning the copper with an alloy of tin and lead, and for glazing the ceramics, not the copper itself. Lead causes saturnism.
(see Wikipedia for further information)
Copper is not a very toxic metal for birds and mammalians. I would have a concern not with the copper but with the solders if the alloy used for soldering is not:
- at least a 95% tin.
- cadmium free solder.
A lot of soldering alloys are 50% lead/50% tin and are not suitable for food and drinking water contact.
Another alternative is brazing with alimentary silver brazing alloy (cadmium free, and very, very expensive) and maybe phosphorous copper (I haven't checked the suitability for food contact). But brazing asks for an oxy-fuel torch and is it's out of the purpose of this instructable. was from the pipes (where we get the word "plumbing" from) as well as the flatware for eating with, the plates and bowls, the fact their wine was cooked in lead cauldrons and drank out lead cups, babies were given lead to teethe on as well as what you mentioned.

one thing i have to say is get solder from the plumbing section of like home depot or lowes. what they sell if what is used in copper water lines and it *is* food safe.
To explain a bit further, the word 'plumbing' comes from the ancient word for lead which was 'plumbum'. This is why the atomic symbol for lead is 'Pb' and not something like 'Ld'..
agis68 Moodie-13 years ago
wow....thanks for the notification
thank you for the addition. i cant believe i didnt think to say it myself really.

oh yes and i caught a typo in my comment. i meant to say "what they sell *is* what is used on copper....." not *if*. -sighs-
tig1 agis683 years ago
I think it was lead they were cooking in. :) Wika galvanize,not a good choise for cooking in :)
That may have been the lead that killed the Romans.
The problem with the roman empire was the use of lead in copper alloys.
acoleman33 years ago
great instructable! being a coffee lover as well as someone who dont like to rely on electricity, this is perfect

but umm.....with the concern for copper and food? let me ask you this....whadia think they use for residential water lines to the sink tap. yeah....copper. if it was so toxic....there'd be no way in hell building codes would allow it to be used. especially with how stringent they're getting on health issues. copper is safe....*aluminium* is *not* safe. the oxides toxify the body since the liver is unable to filter it out.
i do have a design ? though. cant you make the fuel chamber out of copper, solder a copper disk to the bottom and drill it out with like.....either a 1/64 or 1/32 in drill? then solder that to the combustion chamber and use a cork at the top to seal it. idk....i thought i'd run that by you and see what you thought.
urant (author)  acoleman33 years ago
Lost you on the cork, could you expand you idea a bit?
acoleman3 urant3 years ago
lol my apologies....i was still waking up when i wrote that.

instead of the syringe, have a copper chamber with a thin copper disk soldered to the bottom of it with a 1/64 or 1/32 hole drilled in its center. then solder that to the burner where the syringe would have been as the fuel chamber. to hold the fuel in.....cork it.

in theory, the hole in the disk should be small enough to get the proper fuel flow as well as being more durable and integrated. less parts to go wrong, less parts *will* go wrong.
urant (author)  acoleman33 years ago
ahh, know I understand. Yes, you could do it that way, but the hole has to be way smaller. The smallest drill bit I have is 1/64 and that was still too big; it flooded the stove. The best solution I could come up with and that would satisfy the design constraints was using a syringe. You could very well use a 1/64 drill for a large, more powerful stove and bigger espresso maker.
acoleman3 urant3 years ago
huhh....ok. well what about some of the smaller dia number drills. is there something along those sizes that would work?

oh and thank you for you answered a ? i had about *my* project. i want to make one big enough to use a house hold espresso machine filter.
urant (author)  acoleman33 years ago
Yes, It would work beautifully. The thing for me is that being a bit clumsy and heavy handed, the only way i could drill a hole that small would be with a dremel strapped into one of those mini vertical drill jigs that they sell, over wise I would snap the drill in no time.
acoleman3 urant3 years ago
well bugger....yeah i can see why you went with the rout you took. thanks for taking the time to talk with me about this.
urant (author)  acoleman33 years ago
Thank you for taking the time to view this and comment on it!
The problem with copper toxicity arises when it comes into contact with acid foods. The more acid with more contact time, the greater the likelihood that copper will leach into the food. Coffee's acid level are sufficiently significant for it to be avoided being made in a copper utensil. The toxicity that results does cause gastrointestinal illness. Coffee pots for making classic Turkish or Greek coffee are often tin lined but the tinning does break down or is often penetrated by vigorous scrubbing to remove tannin stains so it loses its effectiveness.
I like the solder it makes it look kinda steam punk.
Panamaboob3 years ago
In France I have found all sorts of used copper pots, but they need retinning, and while I have drinked out of copper water pipes soldered with led/tin, I dont think Id want to cook or boil something in copper, especially copper that has been soldered with lead solder.

The copper pots that are sold for immediate use are either tinned on the inside or have a stainless steel inner coat.

I believe that coffee is acidic...what would be the reaction of this "acid" with copper? I know you can polish copper with catsup....where does the "oxide" go...

Better safe than sorry...
I'd personally steer away from lead solder as well and use silver solder, however, I don't think that it'd be too much of an issue, unless you consume a lot of coffee, the acid reaction with the lead does cause some concern however. But coffee is a fairly weak acid, with a pH of ~5. You would end up with lead acetate, which is poisonous, but by the looks of it, it's not that bad except in larger quantities.

Copper is a relatively nonreactive substance, and coffee is a weak acid, so there wouldn't be much, and it would appear to be non-toxic.

Lead solder is a bit dodgy, the rest is fine.
if you use solder from the plumbing section of your fav diy, you wont have to worry about lead. idk why people still think residential water lines are assembled with lead solder. that is so archaic its not funny.
I think that depends on how old you are.....
wow....then i guess you must come from the "lead plumbing solder" generation cus im 34 and lead free solder has always been used as long as ive been around.
Uhh, uhh, watchu say?
thats right the pre-lead free generation, ...dribble, dribble...sonny boy....
Lead is cool...uuh, uuh...hmmmm?

Times do change...for the better...
I didn't say that it was.

I'd imagine that a lot of people would use electrical solder though, which does contain lead (or at least my 20 year old 3 kg roll of solder does).
oops! umm heh....sorry i clicked on the wrong reply button. you're right though, most people associate solder with radio shack......not lowes or home depot. i guess its us diy'ers who think of water pipes before electronics lol.
I thought about this issue some more...Might it not be better to just carry around some coffee bags or instant espresso?
They'd fit in your pants, too..
But they don't taste anywhere near as good as freshly brewed espresso.
moldyclint3 years ago
Beautiful! Simple, compact, and meets an important need. Kudos for your explanation as well as discussion of design process. Cheers!
acoleman33 years ago
north america health standards have determined 10 mg/day is the health cap, and even then its said its not likely to pose a health risk to adults in the general population.

what *is* toxic is copper(II) or cupric oxide also known as tenorite. this is the higher oxide of copper.

this is what is said about cupric oxide: Copper(II) oxide is an irritant. It also can cause damage to the endocrine and central nervous system. Contact to the eyes or skin can cause irritation. Ingesting cupric oxide powder can result in a metallic taste, nausea, vomiting and stomach pain. In more severe cases, there may be blood in vomit or black or tarry stools, jaundice and enlarged liver. Blood cells rupture resulting in circulatory collapse and shock. Inhalation can lead to damage to the lungs and septum.

this is what is said about copper(I) oxide: Copper oxide is used in vitamins supplements as a safe source of copper and over-the-counter treatments. Copper oxide is also used in consumer products such as pillowcases and socks, due to its cosmetic and anti-microbial properties. The risk of dermal sensitivity to copper is considered extremely minimal.

as i said before....copper is not toxic. i wish people would do basic research instead of throwing out uneducated opinions. i found all of that in a wikipedia article just by googling "copper oxide health hazards" and did it in less then five minutes.
From what I've quickly read on Wikipedia, copper(II) oxide isn't really that much of a concern, as it is formed by copper(I) oxide degrading. It's formed by the oxidation of copper by oxygen, which won't really happen in a coffee machine, and not very fast either, you need quite a bit for it to be harmful too, I've heated copper up to ~500C and all it produces is a thin coating of copper(II) oxide, which I've then handled without harmful side effects. So in essence, you're right, no-one needs to worry about poisoning.
hate to be contrary, but this is whats on the msds for cupric oxide.

Section 3 - Hazards Identification

Appearance: black to brown black. Warning! May cause eye irritation and transient injury. Causes skin irritation. Causes severe respiratory tract irritation. Causes digestive tract irritation. May cause central nervous system depression. May cause liver and kidney damage. May cause blood abnormalities. Inhalation of fumes may cause metal-fume fever.
Target Organs: Kidneys, central nervous system, liver, red blood cells.

Potential Health Effects
Eye: Causes eye irritation. May result in corneal injury. May cause conjunctivitis.

Skin: Causes skin irritation. May cause skin discoloration.

Ingestion: May cause central nervous system depression, kidney damage, and liver damage. May cause gastrointestinal irritation with nausea, vomiting and diarrhea. May cause circulatory system failure. May cause vascular collapse and damage.

Inhalation: Causes respiratory tract irritation. May cause ulceration and perforation of the nasal septum if inhaled in excessive quantities. Inhalation of fumes may cause metal fume fever, which is characterized by flu-like symptoms with metallic taste, fever, chills, cough, weakness, chest pain, muscle pain and increased white blood cell count.

btw...the information from my previous post *also* came from wikipedia. it was a direct quote no less on both cupric oxide and copper oxide under section 3: health effects. so i have no idea what article you looked up to find that copper (II) is non toxic.

i do wish to thank you for seeing how copper (I) oxide is *not* toxic. at least someone had the wisdom to also look it up.
Shoot. Another good 'ible for my to do list.
i wonder if this could be cut down used to fit. the rubber doesn't under preform and the gasket head/ filter is really strong i know it could be in potential breach of you rules
urant (author)  tdawber-mandeno3 years ago
Yes, it could.
BTW, my rules don't need to be your rules ;)
I know but it makes it so much more fun
urant (author)  tdawber-mandeno3 years ago
Yes, it really does :D
gotparsley3 years ago
Any chance you could elaborate a little on the four holes drilled into the 1" to 1/2" reducer? Perhaps take a picture or something? I'm just a little confused. Thanks!
urant (author)  gotparsley3 years ago
Sure thing.
There air holes. The stove sucks air from those holes and the exhaust leaves up the chimney.
Void Schism3 years ago
Brilliant instructable! Great to see an original idea with the design process, something that non-engineers might not know to go through
urant (author)  Void Schism3 years ago
Yes, that was part of the idea, here's me hoping some kid will read this and get inspired to design and build the next great thing.
Damn man you have one hell of a head on them shoulders don't let it go.
urant (author)  monsterbuddy103 years ago
Already lost it to a young lass that I made my wife ;)

Thank you for the compliment!
Hey, is that an espresso machine in your pocket or are you just pleased to see me?

Genius idea BTW. Perfect instructable. i.e. clear instructions and something that nearly anyone could knock up themselves by following the steps.

I think I have found my weekend project.
urant (author)  skirmishmonkey3 years ago
Hope you post some pics come Monday :D
siafulinux3 years ago
*Bows in humble admiration!*
nice instructables !
iknowad3 years ago
Interesting concept. But this is not ture espresso. This more more like an integration of a burner and moka pot. The necessary brewing pressure that classifies espresso is at 135 psi or 9 bars of pressure. Tose pressures are capable of producing the crema that espresso is known for. Good idea though.
awalsh53 years ago
I'm concerned about the amount of lead (in the solder) in a device for human consumption. The device is also heated to boiling point which makes the lead softer and more likely to contaminate the water. The metal filter could also be made by scoring horizontal "v " shaped channels on one side then vertical channels on the other side. Where the channels cross would form very fine holes if the depth of the "v" is right.
urant (author)  awalsh53 years ago
Great idea on an alternative way to make the filters! (btw, I did use non-lead solder)

This might be a great thing to mention in bold in the instructable itself for those who don't read the comments and have just the right (wrong) balance of ingenuity and lack of foresight to end up building their own one of these that slowly poisons themselves.

I'd even add a design constraint "The product won't kill me" since from the comments it looks like that was in fact one of your constraints.

It's probably worth mentioning the copper concerns that people have mentioned as well. It'd be a shame to have such a beautiful creation kill its maker.

refer to my post on copper to see my research findings on "copper poisoning".

All I'm saying is that it might be nice to include this information in the instructable itself. It sounds like what was built was perfectly safe, but clearly there are a bunch of people with concerns - founded or not. It sounds like the maker has built something safe.

Also I took the few seconds you said to do some googling, and found that under certain conditions, cookware can also leech toxic amounts of copper:

I'm sure it's all more complicated than that though, but I didn't make the instructable. I'm just recommending that the instructable be updated to include safety concerns. Maybe I'm wrong though. If it would be nigh impossible to build this device with hazardous materials that may result in poisoning the user, then a warning is likely not necessary in my opinion.

urant (author)  KarmaAdjuster3 years ago
Took you comments to heart, called a MD who's a friend and asked you to look at tje 'ible and give me her thoughts. I added an extra step in me intro.
Thank you for helping me make this a better 'ible
The coffee may well kill you at the same rate as the copper - a bit slowly, say, 60 years?
lead has been removed from commercially available pluming solder, hasn't it? Use silver solder?
Yes it has. It is also immune to the softening from the heat from boiling.
You're right about the solder problem. But it's easy to solve.
As building codes currently almost universally require the use of lead-free solder for potable water piping. This:

is commonly available.
just use lead-less silver solder.
ldmorgan3 years ago
Lead-free solder is non-hazardous, being 94% tin and 6% silver. It is also called silver-bearing solder.

The copper construction is also non-hazardous.

The ugly soldering can be improved and made even easier by stove-soldering: flux and assemble the parts, lay them in an old metal jar lid, and set them on an electric stove burner. Turn the burner on high, and when the parts are hot enough, turn the burner off and touch the solder wire to the joints and they will flow perfectly.

Then use a pair of pliers to set the lid full of parts off on a cool burner until they can be handled.

Note: Burn any paint off the jar lid before using, or it will smoke. Do this in a small fire outdoors. The dirty (sooty) lid will not solder to the parts when used.

You can clean the cutwork up (and drill the filters) with a Dremel tool.

FINE job, by the way.

urant (author)  ldmorgan3 years ago
That's really a great idea! I'll try it the next time I have to solder big pieces of copper, which may be soon, because I've been asked to make 3 more espresso makers as Christmas presents.
Edgar3 years ago
Not only it's a great idea, Steampunks will make it into Art!
(of sorts...)
urant (author)  Edgar3 years ago
Yes, please steampunk it!
Urant. Very clever design. The "problem" was not so simple to solve and you did it with elegance. That gives ideas...Bravo!!!
urant (author)  Ilan Voyager3 years ago
Yes, it was one of those projects that you gut tells you is possible, but it's a bit harder than you think. My wife tells me that's the most common way I get into DIY trouble: I utter the phrase "ohhh, how hard can it be..."
VoidKeeper3 years ago
You think it would be possible to change the alcohol stove with an electrical one? might add some bulk to it, but even if it were slightly bigger I don't think it would be a problem.

I'm just trying to figure out how to build it using a 9V battery, maybe using a wire wound coil in the water to heat it up, I just wonder if it would generate enough heat, or even if it would damage the battery... mmmmh, something to check out I guess.

The only reason I'm posting this is just because I showed this to a friend and she asked me is it could be done with a battery =P. Maybe I'll do some tests, see if it generates enough heat, maybe for such a small amount of water it'll be enough, although I'm not too sure about that, also, not too sure about how safe it would be, I'll post any results if I get the time to test some circuits.
urant (author)  VoidKeeper3 years ago
Before you start to experiment, a little tip. Part of the energy that the stove needs to produce is to heat the espresso maker itself. I don't know if the amount of energy in the battery is enough to heat the machine and the water, but it will help you a lot if you thermally isolate the machine.
Keep us posted! That opens up the lucrative college student portable espresso market!
mysss3 years ago
This is amazing. While I kind of fear the power a pocket espresso maker would give me, I'll certainly be coming back here when I finally get around to making an alcohol stove.
urant (author)  mysss3 years ago
Try modding the stove in this project. It's safe (it won't burn you i you happen to accidentally tip it over) and you can refill it while it's still on.
darkblood3 years ago
I'd be tempted to see if anyone makes a cheap pressure relief valve that could be added to the boiler.... To prevent the boiler from failing catastrophically in the event that the outlet port becomes plugged. I bet there's something in the auto-parts department waiting to be re-purposed.
The pressure would most likely blow out the obstruction with a pop and make a mess. I wouldn't be worried about explosions.
urant (author)  lukeyj153 years ago
You know, I did try to make the boiler fail. It survived without a problem, probably due to the small diameter/copper thickness and the fact that there isn't that much water in it to build up enough pressure to blow it up.
astrong03 years ago
Not to be crude but I just have to say it, why excuse me sir but is that a pocket sized espresso maker in your pocket or are you just happy to see me?

Oh this is just an espresso maker.
Ah...well ain't that a kick in the pants.
urant (author)  astrong03 years ago
Hahaha, the funniest thing is, my wife said something very similar when she took the picture
LMFAO! oh that was *brill*!
Calling a doctor, now that's going the extra mile ! Nice to see a concerned poster. Cheers !
urant (author)  Lectric Wizard3 years ago
It was the least I could do
darnduk3 years ago
Can't help but ask.....are you happy to see me or is there an exresso machine in your pocket?

I would like to see a video of this at work!
80$man3 years ago
Very good ibble! Two things, one, the name: Moka pot rather; two, the solder issue seems a hot topic, could you redesign to use shrink fits rather?
Edgar3 years ago
Where's that "vote" button?
acoleman3 Edgar3 years ago
the stars at the upper right. mouse over them and the degree of approval will be highlighted. then just click and your vote is recorded.
mobiledeb3 years ago
Absolutely awesome idea! I also liked the step by step process from inception of idea right up to fruition! Not only are you a gifted hands on engineer 8) You are a mensa level process writer!!!
urant (author)  mobiledeb3 years ago
Thank you, just made me blush :D
Now you just need to make a milk steamer for your other pocket. Combine the two and you have a latte machine :)
urant (author)  killersquirel113 years ago
you know, if you do mod it and build the steamer, it would be able to power some stream driven machine...something really steampunk
lykle3 years ago
I am only at step 3 and I am already loving it.
For me this is the way an Instructable should be, including design constraints etc.
Great work man great work.
ironsmiter3 years ago
Brilliant little contraption.

Just stay away from airports, government buildings, schools, people, surveillance devices, banks, stores...

Aww heck, better register it with the ATF as a bomb, just to be safe.
then lock it up in your gun safe, bury it in cement, then hope THEY never read :-)
Good point - definitely something to keep in mind. It's a sad reality of the modern nanny state..:\
digus digus3 years ago
This is still absolutely brilliant though. I am building one...
imperio3 years ago
...sono Italiano! l'espresso che ottieni deve essere molto cattivo! [ contatto con metalli: ottone, stagno, piombo ecc]
Non traduco...gli italiani capiscono! cli altri...spero!
urant (author) 3 years ago
Update 2:
I added a picture I forgot to post of the brew head filled with coffee
I also drew up a "zoom" of the stove to better explain how it works
urant (author) 3 years ago
I updated the Instructable to address the following points.
A) use only lead free solder
B) two alternatives to the copper in the brew head.

Thanks for the great comments and helping me make this Instructable better
You might want to mention the lead free thing in the body of the 'structable, it's really important when "food" is involved. Many people don't read the comments. Other that that, great job !!
urant (author)  Lectric Wizard3 years ago
yup, you're right. Just did it. Thanks for the tip!
friger3 years ago
I will be building this little gem, I might up-size it to make a proper size shot of expresso. Well done, excellent Ible.
urant (author)  friger3 years ago
Hi friger,

It will be quite easy to up scale by either make the boiler longer (no need to modify the stove size) or go with a bigger diameter tube.
That one will need a stove re-size.
To do that, you will need to increase the fuel flow rate (start by trying a bigger hole in the cap to increase the drops per second with the syringe).
If that doesn't do the trick, get one of those syringes that are used to inject butter into turkeys and find the correct flow rate by controlling the amount of air that goes into the top of the syringe (use a piece of tape first, and punch small hole in it until it gives you the drops per second you need).
In the stove, increase the diameter of the vapor diffusion plate and if needed, make 6 groves instead of 4
how about an action video.
Agreed - this is a fascinating beastie, but seeing it on the go would be a boon to anybody copying your idea.
urant (author)  Kiteman3 years ago
I friend borrowed it last Sunday and has yet to return it (even went as far as suggesting that it would be a GREAT Christmas present) As soon as I get it back, I'll post a samll video.
nireves3 years ago
Nice build. I like the design process before each step, that overview is sorely lacking in many instructables. (Give us the big picture first!)

I think what you've made here is a side-chamber, self-heating, Moka Pot.
which is a very cool thing that you've come up with.

The fluid flow is about the same between your device and a Moka Pot, except your brew-chamber is next to the heater rather than over it. The slightly pressurized water is forced out the exit tube by the pressure increase in the heating chamber. It then flows through the coffee grounds and out to the atmospheric pressure environment. Your deign needed to move the brew-chamber to the side to allow the exhaust of the alcohol stove to rise up and out.

This is not a criticism - I love the concept, the design, the build, and the 'ible. I just wanted to point out that this is similar to a low pressure Moka Pot rather than a higher pressure espresso machine.

A "Pocket-size Moka Pot with integrated alcohol stove" is still a very cool thing.

urant (author)  nireves3 years ago
Yes, you are right and...well, " Pocket-size Moka Pot with integrated alcohol stove" does sound really cool :D

I did decide to call it an Espresso maker because I thought more people are familiar with that term that a Moka Pot, and since a bunch of cheap, electric moka pots say "espresso maker" on the box (and the definition of an espresso is a bit lax) I went with the more common name
rhead3 years ago
Plumber here: nothing wrong with alil lead in the solder. Most water mains in new york City are 100% lead, and the ones that are not still have lead inside of the water meters so the amount of lead you will receive from this would be the same as drinking some water out the tap. Leads in alot of products not a big deal.
dnullz3 years ago
Somebody is playing Xbox while the rest of the class is at the prom...
ilpug3 years ago
This is quite simply one of the best ideas i have seen on this site. Hands down.

I must say however, that I doubt the safety of copper and solder when used to cook, especially at high heat.
TonicLime3 years ago
I like the idea!
DNAgent3 years ago
I'm curious as to what kind of solder you used. Is it an alloy that doesn't contain any lead?
urant (author)  DNAgent3 years ago
I did use a lead free solder. I got it at Home Depot and it's used for water tubes. It says "Lead Free" on the I decided to trust them
kwall43 years ago
Bravo, Bravo!
The best instructable I've ever had the pleasure of reading. I've been guilty of boxing up either my home or office espresso machine for extended trips.

This may be one of the best written instructables that I have read. Informative and entertaining; especially regarding your heat source. I kind of felt like I was reading about a DIY, portable drug lab.

I've got to build one of these before our next winter black-out.

Good Job!
rotoqueen3 years ago
LOVE it. Love the idea, but most of all, love reading the instructions and getting the feel of your creative mind in action! I want to try this! It will be my first time with solder and I'm thinking of making it "steampunk" looking, (steam gauge, etc)!! It probably won't fit into my pocket after I start adding stuff, and kinda defeats your efficient design, but that's okay! You made a very inspirational design, thanks for sharing! (Applause, applause!!)
urant (author)  rotoqueen3 years ago
Rotoqueen: If you make one, you will make my week :D
ancienthart3 years ago
Did you use lead-based solder?
Does the solder come in contact with the hot water?
Plenty of lead-free solders.
actually pretty hard to FIND leaded solder these days.

Yes, there will be SOME contact between solder joints and the water/steam/expresso
I had a concern about the solder as well.
Most solder that you can use with a soldering iron are primarily tin, which has a low melting point, and I would worry about the longevity of it in a piece that includes its own alcohol stove. In addition, solders with high tin content aren't very strong.
Some quick googling tells me that tin has a melting temp of 449 degrees F, whereas silver is 1761 degrees F.
There are many solders that are mixes of both tin and silver from plumber's solder all the way up to jeweler's solder that I think would fit this application better and safer for usability.
urant (author)  Squee3 years ago
Hi Squee,

Yes, this also worried me. The thing is, that the stove doesn't have enough fuel to get the machines temperature high enough to melt the solder. I actually did a test to see if my logic held up. I loaded the fuel tank, filled the stove with water and then blocked the brew head. I got hot, but the stove ran out of fuel before any damage was done.
urant (author)  ancienthart3 years ago
No, I used a lead-free solder
mikeasaurus3 years ago
Awesome, I want one for fresh java on the go!
FoolishSage3 years ago
Great instructable. I've got some caffeine addicted friends that will freak out with this next time we go camping!
Sovereignty3 years ago
Absolutely awesome. An original.