microwave smelter

Remember how your parents used to say "don't put metal in the microwave"? Prepare to throw that cardinal nugget of advice straight out the window because we're going to do just that. We're going to use a domestic, unmodified microwave to melt metal! 

I happened upon an article in an old Popular Science magazine (c.2003) about microwave smelting and thought it was so awesome I had to try it for myself. So, just what happens when you try to smelt metal in the microwave? Turns out, it works!

Also, if you do it wrong you end up with a fiery microwave disaster:
Want to see how it's not done? Let's go!

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Step 1 Tools + materials

tools: oven mitts safety goggles + face shield metal tongs / grips old microwave .

materials: stainless steel measuring cup (crucible) silicon-carbide block (details in step 2) ceramic casserole dish / fire bricks tin / lead / silver solder (details in step 2) mold for metal ingots (pancake mold)

Comments

[freeza36]

my science teacher (who by the way is awesome) put a cd in his microwave. he advised me NOT to do it

[State50]

I don't know who had cancer, because I read this after the thing had been censored and cut-up all over. Silica dust can result in lung irritation called silicosis. Constant irritation, due to external influences or toxic chemicals externally or internally made from the environment or stress can trigger cancerous growth abberations in cells. Having said that, I pray for the person with the cancer, that God would act on their behalf for their salvation and healing - in Jesus' name.

[hopsman]

I wonder if some combination of centrifuge/smelter would be useful in spacce applications?

[67spyder]

I applaud Mikeasaurus for including the failure as well as the success. Sometimes we learn more from failures. Plus it will stop someone else from from trying it.

[flie727]

BIG TIME SAFETY WARNING!!!!
NEVER pour toward yourself  & Please wear safety faceshield & glove!
Somehow make a handle or tongs to allow you to pour to the side!
There is a VERY REAL POSSIBILITY of SPLATTER when the molten metal strikes the mold.
*Extremely Important*: If there is a HINT of MOISTURE on the mold this is not simply a possibility, it will be a reality.
PLEASE, be super careful about this, molten metal burns are not funny!
BTW, I'm an assayer for a refinery - I've had pours splatter & I've seen others have this happen to them!

[Earthscum]

I definitely agree with djimdy's assessment.

One thing (out of all that could be added about safety) that I would like to add, if I may, is ALWAYS HAVE SOMEPLACE NEARBY TO SET YOUR CRUCIBLE.

Worst than having an accident is dropping your crucible and creating bigger splashes. Bear the pain for a split second and put the crucible down. This is why it is important to have someplace in the immediate area.

I prefer a couple bricks (fire), and having a bucket of sand can also be helpful to allow any unused or remaining molten material to flow to a clump in the edge by sitting your crucible at an angle to cool.

I love this idea... it's freaking crazy, but considering using a propane forge, I guess this isn't so bad. At least it won't blow up, and you can just throw a switch to stop the process at any time. I'd like to see someone "in the know" with this process do a Pewter casting before I attempt one, though.

[djimdy]

Great comment and one that should be added to a basic fact sheet or at least pinned to the top of the comment thread.
What makes this so important is that it's one of those 'at the last minute' things you don't realize until you're already there and it's effectively too late.

[Christopher B.]

I was fine with the crazy metal-melting antics, up until you poured water into the microwave. Please, please get a fire extinguisher and don't kill yourself!

[porcupinemamma]

The GoodWill and Salvation army usually have Thrift Stores where you could pick up a microwave for very little cost. Was that what you were wondering?

[porcupinemamma]

I soooooooooooo wish I had the guts to try this!!!!

[jobergy]

if you go to Salvation Army or Goodwill, I have seen several old microwaves for like 10 - 20 bucks! so much better than risking your own! :\

[Capn_Clawhammer]

Dec 19, 2011. 10:53 AMSIRJAMES09 says:

silicon is another cancer causing agent..


I think the cause of confusion on this issue for most might actually be a spelling mistake. *Silicone* (notice the 'e') is in fact a proven carcinogenic compound of several polymeric and plasticine components. *Silicon*, in compound with additives such as carbidinium, may in fact be carcinogenic (I personally don't know for certain), but by itself, its practically an elemental substance and is at least 98% inert. It doesn't break down into other components. If you melt it down (extremely unlikely in ones backyard microwave) it stays the same substance, just in a liqiuid state. It is, in fact, a major component of such naturally-occurring things as basaltic magma and lava, (and of course basalt itself), and is also present in almost every crustral formation on earth. The last I heard, basalt doesn't cause cancer. I may, however, be proven wrong on this. Only time will tell.
.

[jobergy]

Cool story bro.... But seriously, may I ask why I was spewed all of this information as a reply to: [quote]

"if you go to Salvation Army or Goodwill, I have seen several old microwaves for like 10 - 20 bucks! so much better than risking your own! :\"

I read this in my email and am confused beyond belief, but i learned something non-theless :P

[porcupinemamma]

Tell you what, why don't you come over? "My mom makes a he## of a brisket" Bazinga ;0)

[jobergy]

HAHA! I LOVE THAT SHOW!!! Sheldon seriously is what makes it great.

[lasersage]

All these people worrying about lead poisoning and yet nothing about the fumes from the building foam :)
I'd be more concerned about breathing that.

Have any of you ever read
http://www.gizmology.net/stovetop.htm

there is a fantastic article about smelting Zamak. Its Zinc, because of its low melting point, with Aluminium (and a touch of copper) dissolved in it.
Makes for a very useful alloy for casting, but can be made at relatively low temperatures.
The next candidate for microwave smelting?

[bonpierce]

You do realize this contains LEAD right? Lead is a carcinogen whether it is being melted or held in your hand a a charm or around your neck as a necklace.

You don't want long exposure of any kind to this stuff. Seriously.

[weesuzi]

hiya folks Safety is a myth, risk is the reality. Paracelsius said " The poison is the dose" in the 15th century. As abinger says below, risk/dose increases with, time exposed and the ability of the product to get into your body due to its form (gas, fume, mist, powder, pearls, bricks...its pretty hard to inhale a brick). Spoken by someone with 16 nuggets of mercury amalgum in his gob(mouth) I feel Ok about it. Loook at it this way Acetic acid /vinegar pretty much the same chemical different concentration use one in the lab and a lower concentration use it on your chips(french fries) Whisky....like drinking it ...but don't want it in my eye. Same chemical same strength different risk. Phosphoric acid used as a disenfectant sanitiser in breweries, used as a main ingredient of Coke...okay bad example. As a safety professional( and ex lab tech with 30 years behind the bench) I genuinely appreciate people's need to communicate safety ideas and protect their web community friends. High five hazard spotters! But educate yourselves to the risks not just the hazards. Google EH40 and you will find the UK occupational exposure standards for all controlled chemicals and peruse the Health and safety executives website at www.hse.gov.uk all info free and usually pretty practical. I would love to write a safety bible for this site but where would you start and end..ohh yes Asbestos to Zoonoses (an A to Z of not so common sense) Bout ye.

[terpodion]

Lead isn't a carcinogen. It's a toxic, heavy metal - a poison. That's different. It isn't going to hurt you unless you ingest it, either by eating it, chronically getting lead paint (which isn't sold anymore) on your skin or by inhaling the fumes after it reaches it's vaporization point which is a whole lot higher than it's relatively low melting point. If one were to smelt lead every day, there would be danger. One time isn't dangerous if you are the least bit careful.

[samurai1200]

So why is there this huge push away from it for consumer (and most other) electronics?

[SIRJAMES09]

AMEEN!

[terpodion]

Because it if it ends up in landfills it contaminates the water table. Of course, every public waste disposal site that I know of keeps electronic junk out of the landfill and recycles it properly but because it once did end up there; politicians created the legislation to eliminate lead in all forms. Makes for good campaign bragging rights. "Senator Jones drafted legislation to eliminate lead and protect our children."

[paqrat]

I think too there is a certain paranoia about lead. This paranoia is, in part, spread by certain legislators who, in an effort to look as though they are actually earning their salaries, play up the supposed dangers of "demon Lead" and pass legislation against it. If the web site I looked at earlier is correct, easy flow silver solder contains cadmium which is definitely something you don't want to breathe the fumes. I have read cases of jewelers killed by melting cadmium and breathing the fumes. I have yet to see anything about anyone dying from melting lead. If melting lead was that dangerous plumbers should have been dropping like flies before legislation banned it in plumbers solder. I believe the effects lead has on the brain and nervous systems of immature humans is the main thing we must be careful of when dealing with lead and that is more likely to incur through ingestion.

[gladiator327]

Then why do we still use Lead Acid Batts for vehicles?

[static]

Lead Acid batteries are still being use for vehicles because an all around substitute hasn't been created. The hazards of using them have been mitigated to a large degree on both the manufacture, and consumer end. The salvage price for lead has always been constantly high enough that persons in the know, never sent them to the land fill. The high deposits we see now on new batteries is to keep the ignorant, and lazy from sending them to the landfill.

[skrubol]

Also, due to the large deposits encouraging battery exchanges, something like 98% of car batteries are recycled.

[terpodion]

Because there is no acceptable substitute. It's pretty much as simple as that. No other type of battery can stand up to the thousands of cycles of charge / discharge, put out as much current and withstand the environmental conditions that vehicles are subject to. At least not in that price range. How would you like to have to pay $350 to $700 for a car battery (installation not included)?

[skaar]

i've read that iron acid batteries are better for lifespan and resiliency, but they're low capacity. now ni-mh could be used, they have low size, high current and capacity. at least acid iron could be built at home.

[samurai1200]

This is a good point. It's easy enough to find "Lead Free" solder these days (Sn-Ag-Cu), people should just use that if they plan on handling their ingots (as a paperweight, etc) created here.

[yogadavid]

Lead free solder was used in a lot of volkswagons, xbox, and pretty much everything else where the environmentalist went on a rampage to get rid of lead. that is why you get the red ring of death in an xbox and your airconditioner in your volks wagon. Especially in deisel. Environmentalist did not think ahead about all the crap going into a landfill because it can't stand up to any heat and or vibration.

[static]

Would appear that not all lead free sold alloys are created equal. Who knows exactly why they weren't properly researched by manufacturers, or those specifying manufacturing specifications prior to their use? This is not the first time a change(for any reason) in manufacturing methods created problems, and it will not the last. Of course it's all the fault of the environmentalists.

[canucksgirl]

You realize however that lead-free solder is actually worse for you.

[wocket]

Certainly is. Always read the material Data Staftey Sheets about any of these things.

[samurai1200]

*citation needed.

[canucksgirl]

I had originally heard about a Danish study through a television program, so I had to do some quick research to get you facts you can read yourself.

Heres a pdf from a company called OK International, who is a global supplier of soldering products. In it they reference the study and explain the results. Obviously being a supplier, they have no reason to manipulate the results either way...

[icyfyer]

While I find the linked PDF interesting, I can't give it much credibility because of their inability to correctly quote the name of the largest occupational safety organization in the US. It seems like a miniscule detail, but they're making a lot of claims, and citing a lot of other works, not to have done their research, or at least proofread the work before publishing.

[canucksgirl]

Yes, I see too that they referenced OSHA incorrectly as OHSA.
I only chose this source because (someone here wanted me to back up my statement and) Ok Int. references the Danish Study that I had heard about from a TV program.

If anyone wants to read the full Danish Study for themselves they can read it here.

[chamunks]

Wow thats really quite the paper I said to myself I'm just going to skim it than I got to the end and was like wow that was informative. I reccomend that to anyone who wants the real scientific answer to whether or not LeadFree Solder is More harmful to you. Which apparently it is.

Que instructable about making an effective deskmounted airfilter for your soldering station.

[canucksgirl]

I'm glad you found it informative. Too often people just assume that lead-free means safe and they use it without proper ventilation, doing god only knows what to their lungs...

In fact, an Instructable member has already made an inexpensive air filtration system that was intended for use with soldering.

You can see it here.

[chamunks]

Well thats handy, I dont exactly work in a production environment where I'm soldering ALL day. But this is good to know I also was under the same assumption.

I've been using this stuff the "Special Blend" at Sparkfun, http://www.sparkfun.com/products/10243 enjoying it quite a bit I will definitely look at that Ible though I do really appreciate my lungs. :)

The area I work in is a pretty open area but its probably still insufficient.