Introduction: DeskTop Steam Boiler

Picture of DeskTop Steam Boiler
This is an instructable for my small sized steam boiler.  I wanted a solid boiler that I could use to run small steam engines, turbines or in this case a "steamfuser" which is a heated aluminum container that lets a scented liquid vaporize and be carried into the air with the rising steam...there are store bought units that will do this much more safely with flicking lights and scent infused paper, but lets be honest, fire, steam, copper and brass win hands down.

The unit was built entirely in my apartment with a hand drill and a rotary tool.  I used a small soup can for the boiler and some various hardware store fittings to plumb the system.  If your looking to make a little, attractive looking boiler to steampunk up your place read on!

Step 1: Parts

Picture of Parts

The main parts you'll need for this build can be changed wildly depending on your available materials.  I picked up most of my parts from my local hardware store and a couple items from a hobby shop.  The main things you need are a soup can for the boiler body, some heat resistant tubing to carry the steam around (I used model airplane fuel line), and a little bit of sheet metal to form the boiler housing (I used brass sheet) and some 1/4" copper tube to make a few connection points and the heating coil.  A torch and solder are also needed to make a few connections...the one pictured is massive and while it did work I used a small handheld one for most of the connections.

Note : The vinyl tubing picture DOES NOT work which I soon found out.  Silicone is the way to go for the high heat resistance.

Step 2: Boiler-1

Picture of Boiler-1

First you will need a small soup can and a drill bit just slightly smaller then the tubing you plan to use.  In this step we will drill 2 holes into the soup can to empty its contents (pick a can of something like broth or tomato paste to make emptying easier).  The 2 holes in the end of the can will serve to hold a small section of tubing which will act as our sight glass to see the water level in the tank.  Make sure your tubing slides into these holes quite tightly as it needs to be airtight.

TIP - flushing hot water into one hole will help move the contents out a little easier...especially if its thick expired tomato paste like I used.

Step 3: Boiler-2

Picture of Boiler-2

Once you have the contents of your can removed you will drill the 3rd hole to work as the filling hole.  I chose to use a small brass fitting and matching plug to make opening and closing the boiler easy.  Once you drill this 3rd hole you want to make sure the inside of the can is as clean as possible as this is the last time you will have easy access to the inside.  After sizing my hole to my fitting I gave both the brass fitting and hole a light sanding to rough up the surface to make soldering easy.  Screw the fitting into the can and apply a small amount of flux to keep the joint from oxidizing.  Heat the thicker brass fitting and then the can until you can easily flow the solder into the seam.  Once again all joints must be air tight so take your time and do a clean job. 

Once the soldering is compete clean any remaining flux from the can.  The only solder I had at the time was silver solder (expensive) and general electronics solder (60/40 mix).  While the silver solder is nice I don't plan on drinking from this machine I used the leaded electronics solder which worked very well on this small job. 

Step 4: Boiler-3

Picture of Boiler-3

At this stage you can cut a small section of tubing and feed it into the sight glass holes.  Clean up any remaining glue reside from the can as we will be starting the boiler housing in the next step.  You can also check the boiler for its "air-tightness" buy installing the fill plug, putting one end of the fuel tubing into the sight glass hole, plugging the other with your finger and blowing into the free end of the tubing.

Step 5: Boiler Housing

Picture of Boiler Housing

Here I used the boiler can to slowly bend the brass sheet to form the main support.  By working the metal slowly in your hands you should be able to form a nice smooth curve.  Take note of the center of your metal sheet to keep both legs the same lenght.  I eyeballed the lenght to lift the boiler high enough off the ground so I could slide my heat source underneath the can.  The height will vary depending on your method of heating (tea light candles, container of liquid fuel...wood fire box???).

Using a straight edge and finger power you'll need to bend 90* feet at the base of the boiler support to fasten the unit to the wood base.  This step is greatly simplified if you have access to a bench vice but since I was building this in my apartment I decided to go with the finger power approach.

I then marked out screw locations, drilled pilot holes into my wood base (Maple) and screwed the unit down.

Tip - Use gloves when working with the metal sheet...while the edges may not feel sharp a small slip of the hand can yield some pretty massive slices...once again speaking from experience.

Step 6: Drilling Fill and Exhaust Ports

Picture of Drilling Fill and Exhaust Ports

I drilled a centered hole to allow my fill connector to pass thru the boiler housing.  When working with thin brass like this its best to start with a small bit and slowly open the hole to the size you need.  Since I didnt feel like drilling larger and larger holes I marked the hole location with a sharpie then slowly cut the metal away with a cuttoff wheel on my rotary tool until I was able to fit a small sanding drum into the hole to finish the edges nice and smooth.

The small 2nd hole will allow the steam exhaust port to clear the boiler housing.  You can see how I slowly cut away the black sharpie mark until I was left with a smooth hole.  I used a sanding drum to de-burr the holes on the inside to ready the housing for the boiler installation.

Step 7: Steam Output and Pressure Testing

Picture of Steam Output and Pressure Testing

Using the boiler housing as a guide mark the location for the steam output pipe.  I used a short section of copper tube which fits VERY snuggly inside the airplane fuel tubing.  Once again I sanded both the copper pipe and boiler body prior to soldering the connection.

After soldering the boiler body is complete.  Since we are not using a blow-off valve to prevent the tank from rupturing under a closed valve situation I decided to see at what pressure the tubing would pop off (assuming it would).  The safest way to carry out this task is by completely filling the boiler and connecting line with water then using a air pump to pressurize the system.  By using a large volume of incompressible water we minimize the amount of compressed air inside the boiler which greatly reduces the concussive force if the can were to rupture before a line popped off.

I used a shock pump which has a built in valve and can pump to extremely high pressures (200-300psi) very accurately to test the system.  I placed the boiler in my kitchen sink, connected the pump and boiler with a section of tubing and started pumping.  Out of the 3 tests I conducted the hose popped off at 50psi...a nice simple safety device.

Step 8: Boiler Supports

Picture of Boiler Supports

Now that we have a functioning air-tight boiler we need to support it inside the brass housing.  I used small 1" wide sections of brass bent into rectangular cross sections.  Metal this thin is easy to cut with scissors and bends easy with small flat nosed pliers and fingers.  The bent supports will not sag under the load of the water filled boiler, especially once they become hot from the heat source.  Your could simple use sections of threaded rod for boiler supports but I used what I had on hand (plus I have billions of those little brass screws and I like the looks of them).

To get the fuel line to slip over the copper pipe take a great deal of skill and dexterity.  I found it easier to add a little water to both the tube and pipe to help them slide together smoothly.  Also be sure to take any sharp edges off the tubing to keep from cutting the silicone.

Step 9: Shutoff Valve

Picture of Shutoff Valve

As I also intend to use this boiler to run a small engine or turbine it was important that I could close off the steam supply to allow the main tank to build up pressure.  I used the smallest 1/4" valve I could find at the hardware store and added to copper ends to it so I could attach the fuel lines to it.

Not much involved in this step, just make sure the screw together fittings are wrench tight.  You want the brass couplers to compress slightly into the copper to ensure a good air-tight seal.

Step 10: Infuser Vessel

Picture of Infuser Vessel

After searching around my house for a suitable container to wrap the copper heat exchanger pipes around I finally stumbled upon an old body spray can.  Since it was nearly empty I depressed the trigger to clear out as much of the compressed gas as possible then using a small drill I made 2 holes in the top of the can to release any remaining pressure and allow for a way to flush out the rest of the contents.  Since I planned on using a cutoff well to shorten the can I didn't want the alcohol in the can lighting from the cutting disk.

Once the can was cut to size I used a sanding drum to remove majority of the paint leaving a little here and there to add a little character.  I finished off with some hand sanding to clean up some low spots and take any burrs off the edges.

The last and nearly most difficult set was bending the copper coil.  If you try and bend the coil by hand (or around a form) you'll quickly see the tubing will kink.  I tried filling the pipe with sand which works great but its quite hard to get the sand to pour back out considering its small ID.  Finally I settled on filling the section of pipe with water and crimping the ends closed.  I then carefully bent the pipe by hand to match the aluminum can and used the cuttoff wheel to trim the ends and remove the water.  While this worked OK there has to be an easier way.

Step 11: Valve Mounting

Picture of Valve Mounting

As mentioned in my video I have decided to attach the valve to the base in a simple method that will easily let me remove the assembly later to try out different designs.  I placed the valve on the base where I wanted it to sit and marked 4 hole locations.  I then used a small drill bit to make thru holes and finally used a small end mill in my rotary tool to notch out the bottom.  Through these holes I ran wire and basically twist tied the switch down. 

I toyed with the idea of machining a nice channel for the valve to rest in with my CNC machine (also homemade) but came to the conclusion that not all people have a CNC machine in their apartment :) .

Note - If your interested in the CNC machine you can find my build thread (with DXF drawings of this machine) over here:

Step 12: Final Hookups

Picture of Final Hookups

From here all the major work is complete.  To fire my boiler I had planned on using tea light candles...after taking a look thru my cupboards I realized tea lights were scarce, there were none to be found.  I did however have a couple copper end caps which I figured I could burn alcohol fuel with.  I was going to devise a neat little wick system but decided to go with the KISS rule and simply sanded the oxidization off the end caps with some fine sandpaper and used it just like that.

Also mentioned in the video I connected the heating coil to the valve with a short section of fuel line.  Initially I had the output from the coil routed to the side but I didnt like the fact that it would spit water onto my table from time to time so I ran a silicon tube back into the side of the "steamfuser" core.  Not only did this solve my water problem is also helps carry the scent into the air much better...which I think is still trumped by the smell of burning alcohol, unless thats the smell your going for in the first place.

All in all I am very happy with the results of this build.  I kept the cost low and functionality high.  With the modular design of the steam output I can attach all sorts of little creations, now that I know the heat output of this little core I have the idea of using steam power to melt candle wax, to make candles, to heat water in the boiler.  Its uses like that which make me smile.  Devices built for the sole purpose of running themselves.  

I hope that people take what they learned here and apply it to make the design better, smaller, sleeker or stronger.  I've learned a lot from the many users of this community and thank all contributers for ideas and insight.

Happy tinkering!


xecarol (author)2017-09-08

that's awesome!!!

FyreAntz (author)2016-01-20

Try filling a section of copper pipe with water and seal it on both end and place it in a freezer. Bend the tubing when the water is frozen! The tube wont crush or flatten if your careful, and it drains out when you're done. This works for me!

valvue (author)FyreAntz2016-01-27

I recently watched a U-Tube video on how to bend PVC. He capped one end, preheated some sand with a propane torch, poured it in-- to make it soft/pliable enough to bend it. My point is, "maybe" just putting unheated sand in the tubing would make it bendable without kinking. Interesting project, but like someone mentioned, I'd consider making something move--as in a piston or gears or??? Juss thinkin!

Engineering (author)2016-01-20

Very interesting.

The concern about not having a pop-off valve for pressure is very valid. While the hose popping of at 50 PSI is good, don't let this lead you to a false sense of security. 50 PSI is still a lot of pressure and under bad conditions easily exceed this quickly. Most model steam engines are set lower than this.

Consider adding a pop off to ensure safety as it could prevent injury. Steam explosions are nothing to be laughed at.

Raccoon77 (author)2015-08-13

Be sure to burn off the plastic coating inside the can prior to use, or else you will have awful-smelling steam and possible spontaneous fires/explosions. A way around this is to use a pineapple can (they don't have the internal coating due to pineapple's acidity).

Kinnishian (author)Raccoon772016-01-19

Wouldn't the plastic internal coating be more important for the acidic stuff, not for the non-acidic stuff? Plastics are typically acid resistant more than metals.

Theoretically the tank should not get drastically higher than 100C (i mean, depending on what pressure you get.) So that is well below typical combustion temperatures for liner-plastics. But below melting temperatures or glass transitions, though.

BoolookN (author)2014-12-03

great! but why only small amount steam air coming out? how to make much more steam?

Raccoon77 (author)BoolookN2015-08-14

Try running pipes through the inside of the can for hot air to pass through, like in steam locomotive boilers.

Raccoon77 (author)2015-08-14

Try running pipes through the inside of the can for hot air to pass through, like in steam locomotive boilers.

joey.heider.1 (author)2014-10-31

Cool building one my self

mr1vizio (author)2013-07-30

What's that tube on the side of the can do

foggy34 (author)mr1vizio2014-02-06

i found this in the comments below.

to quote the author :

The tube on the side of the boiler is a makeshift sight glass that lets you see the water level of the boiler.

itri45 (author)2012-12-02

Is it possible to run a steam engine such as this:
without having to use some sort of pump?

foggy34 (author)itri452014-02-06

not sure what u mean by pump, but all you would have to do is run the output (step 7 above) to one of the inputs on the link you mentioned. ask if you need more explanation. foggy34

nsager (author)itri452013-09-14

I'm Wondering the same thing..

joshabgvghn (author)2013-04-04

Maybe have it nearly all copper tubing but add a small amount of silicone tubing to connect the boiler up

[corosive] (author)2012-11-24

will copper pipe cleared to 65 Degrees Celsius work? Does it need to be rated for higher?

mase2150 (author)2012-10-13

how dud you bend your copper tubing did you heat it up or what

jaksjerky (author)2012-08-04

Great project! To easily bend copper tubing, fill it with water and freeze. Then bend by hand. Works great.

Click796292 (author)2012-07-10

How dee do ( ^ ^ )
I was browsing the internet for good steam projects and man, this one caught my eye. I'm afraid that I may not have any of the materials for this project in my current possession, so naturally being new to this, I wanted to know if you had an estimate to how much this project would cost all together. Where I live we have quite a few hardware stores and hobby shops, but I wanted an idea of how much cash I should have in my wallet before I go running around.

myakka (author)2012-06-14

Hey i was wondering if enclosing a boiler would keep the heat in longer and therfore make it run better?

longwinters (author)2012-03-18

I certainly like your project, but I must confess there is not nearly enough potential for injury or death.

When I saw the steam coming out I thought of a superheated fuel reheating the boiler and the excess being used for a mantel lamp or stove, in other words put fuel in the boiler and use half to heat it, and the other half to cook or produce light.( never mind the fact that that defeats the purpose of driving a turbine.)

Come on isn't the idea of flaming fuel and metal shards blowing in all directions more exciting than just scalding water and shards?

This concept can be seen in the pop can stoves that heat their own fuel and burn quite well on alcohol.

Your soldering seems quite talented so why not but in a smoke stack up the middle and get rid of the wandering flames, maybe a peice of 1/2 copper.

Don't ya just love after the fact advise? Thanks for posting I love these types of projects.

Haha, many thanks for all the kind words. I completely agree with your comments on danger and destruction :).

Falkenzz (author)2012-05-20

I do hope that base wasn't made out of wood...

Falkenzz (author)2012-05-20

I think this creation calls for some random gears to be glued onto the side!

wreckedangle (author)2012-03-13

This might be a dumb question, but how much water is recommended in the can?

Never a dumb question.

I usually fill the can about half way and shut the unit down when its nearing the bottom of the slight "glass". Filling it more then half will just lead to a longer boil damage is going to ensue if you fill er up, might just get some water coming thru the steam lines if you reach a rapid boil and possibly a smaller area for a good head of steam to build.

Trooper555 (author)2012-01-04

I still dont understand what is the tube on the side of the boiler for? is it really nessasary? i still love this design, I'm just curious.

The tube on the side of the boiler is a makeshift sight glass that lets you see the water level of the boiler.

Thanks for the kind words :).

Thanks! I hope you make more Instructables.

cramsey2 (author)2011-12-13

How much did it cost for all the materials?

Going off memory it had to be right around $50 assuming you buy everything pictured.

kingbirdy (author)2011-09-29

so has anyone built any kind of "add-on" to theirs? It seems like it should be more than possible with the modular nature of the system.

dbanbery (author)2011-09-22

I think its a hydraulic valve or microbore central heating valve

viktorg (author)2011-08-24

I have now also build my boiler and it works fine, but it is only the boiler that is ready for now. =)

I have used a solder that is for 235 degreas Celcius, and I hope this is enough?

I haven´t tried the boiler at full capacity jet because I dont want to do this inhouse. I have used a "saftyvalue" that is orginaly used on Wilesco toy steam engines. I have built it with my multi-knife, and mini-burner when I had all the tools in the boat.. but it worked well. :)

sam D (author)2011-08-15

This is a great instructable. I like the 50psi test method - very handy.

A question - what was the wattage of the electrical soldering iron that you mention please?

Confounded Machine (author)sam D2011-08-15

Many thanks!

I actually only used a butane torch for the soldering work on this boiler. The soldering station pictured in the background of the parts photograph is one I use for electronic work and its the weller WESD51.

Baronrc (author)2011-07-24

i love this little boiler! I have been thinking of building a basic steam engine for my son, a little father-and-son project. I was thinking of a wheel/turbine that's rotated by a jet of pressurized steam. I think your boiler is perfect for my needs.

ducktape3618 (author)2011-07-19

wow! i like this. it's very simpel! i think i am gonna make this.

Many thanks, my goal was to keep is simple for everyone to construct.

x-tian (author)2011-07-21

Rubber tubes mostly don't like fire, so you might want to put a small copper tube between the boiler and the rubber, to keep it out of the flames.

Actually the tubing is silicon tubing which can handle much higher temperatures then rubber or vinyl tubing can. However a length of copper tubing would probably look better at the expensive of being a little more difficult to connect.

techno guy (author)2011-04-08

Where can I get alcohol to use as fuel? Can I get it at a store because I will not buy online.

ducktape3618 (author)techno guy2011-07-19

you can buy it at the super market.

ImageMaker (author)techno guy2011-07-05

You can buy the 91% rubbing alcohol (isopropyl alcohol) from the store, if you prefer the grocery store or pharmacy over the hardware store. It's not quite as clean burning as denatured ethanol or methanol (HEET), but at around $2 for a quart bottle, it's inexpensive and does work. Like those lighter alcohols, it will burn without a wick, but you'll get a cleaner, more concentrated flame if you build a burner with a piece of cotton clothesline or similar for a wick.

drahcus (author)techno guy2011-04-08

Most hardware stores carry denatured alcohol that burns well enough. I've used it to run jet turbines before.

mazzas (author)drahcus2011-04-23

I'm guessing that a Sterno can would work nicely.

jgraznak (author)techno guy2011-04-11

I use gas line anti-freeze/water remover sold in the US under the brandname of HEET, in my backpacking beer can stoves. Under $1 a bottle on sale, nearly pure methol alcohol. Easy to find, easy pour bottles, cheap and clean burning.

_Scratch_ (author)2011-06-15

Try acetone, almost burned down my house with it, but it burns clean and with a nice, small and hot flame.

compgeek86 (author)2011-06-04

I wonder if using a little hobo stove like this one:!/
would make for a more controlled heat source without too much complexity?

About This Instructable




Bio: I'm a electronic engineering tech with massive love for DIY building, and tools that make tools.
More by Confounded Machine:Concrete Metal LatheThe Mint Tin MoleskineDWC Hydroponics
Add instructable to: