Smelting iron in a microwave

[Iron Falcon 72]

Interesting experiment. Would it really work?
Smelting Iron Ore in the Microwave

staff warning: trying this may result in your death

Edited July 11, 2009 by mod07

[Glenn]

This looks like it could easily go wrong in so many ways. Microwave ovens are generally used at under 212*F (boiling water) and he wants to go 10x that temp. Plastic, aluminum, and copper parts all melt at lower temps than iron.

It has been years since we purchased our microwave, but I recall a disclaimer saying that you should not use the microwave with metal objects inside.

[Mike Ameling]

It would be something along the lines of an Induction Forge - but without the specific frequencies and safeguards. And the temps involved would end up destroying your microwave oven. Plus iron ore has other ... impurities ... in it that could lead to explosions. Any small rock with moisture in it could explode!

You would be better off using a proper casting crucible and the old Carbon Arc leads from an old style welder. Still dangerous, just a whole lot less.

Mikey

[thingmaker3]

Get all the math right first...

Microwave Steel made at Institute of Materials Processing

[Glenn]

Disassembling then wired the magnetrons together is beyond the ability of most. The sample in the above article was 2-/2 inches dia and 1/2 inch thick, made under lab conditions, and most likely not the first result of their efforts.

It does look interesting, but not recommended for using your mother's microwave in the back yard.

[KNeilson]

I think he took a torch and quickly warmed the kaowool and crucible Then put it in the nuke.........Woulndt the plastic sides melt after 30 min of red hot wool and metal being in there...K

[orgtwister]

well it looks very interesting and i can hear and see the ems on there way for some one trying this in there kitchen

[thisaw]

Looks like smoke and mirrors (or camera tricks) to me.

He starts with the microwave standing on its side, but when it's shown hot, it's setting upright.

The temperature switches alone would have shut it down long before it got that hot.

And if he had disabled them, then the copper tube in the consumer grade megatron would have melted brfore the iron would.

Just my two cents on the subject.

[DClaville]

ehmm.. Microwaves does not affect metal that is why if you put food or any thing organic in a steel foil and put it in the micro wave oven it will not get hot... all that happens migh be some sparks if you are lucky or els nothing happens..

DC

[Sweany]

atually this was discovered several years ago, by a guy who ddidn't know you couldn't melt metal ina microwave, so he did.

If its fake they are doing a pretty good job of fake it's all over the web.

http://www.y12.doe.gov/capabilities/pdf/microwave_fact.pdf

Y-12's microwave casting of warhead parts | Frank Munger's Atomic City Underground | knoxnews.com

Method of investment casting employing microwave susceptible material - Patent 4655276

Microwave melting and casting of metals at 1000 degrees Celsius - A foundry in your kitchen. : WTF

[John B]

Sorry its not strictly smelting iron in a microwave but may be of interest.

I showed this at the recent iForge blueprint weekend we had at Westpoint as a next prgression after you have made the cross.

The attached pictures of a cross with a red glass insert was done in an experiment in a standard domestic microwave oven. (Thought it may be a cool way to put glass eye effects into dragon heads etc)

The glass was placed in situ in the cross and then full power for six minutes applied until the cross became red hot, and the glass became molten and flowed into the central aperture on the cross, the whole was then allowed to cool very slowly to prevent the glass popping out or shattering.

NB If the metal is not suitably shielded it WILL short out the microwave, and the glass must be suitably shielded so it does not adhere to anywhere it is not supposed to adhere to.

The experiment proved it could work on small items, and I am now looking for an easier way to get the glass into larger items

Edited August 28, 2009 by John B
Extra data

[Walking Dog]

Melting or Smelting in a Microwave Oven

Yes, very high temperatures can be attained in a microwave without damage to the oven, IF you know what you are doing. I am aware of metal melting and casting being done very nicely BY USING A SPECIAL CRUCIBLE which is very lossy at the microwave frequency (2.5 GHz). If you are just experimenting without a good understanding of the principles involved, there are several things which could go wrong. However, as long as you don't hurt the integrity of the door seal, the likely damage is limited to 1) a burnt mess inside the oven, 2) a burned-out magnitron, or 3) a burned-out transformer/power supply. Operating with a damaged door seal could be bad for you personally.

The magnitron is coupled to the metal cavity, which contains strong standing waves in operation. The door is part of the cavity. The window in the door contains a metal screen, which makes it opaque to the microwaves, even though it is almost transparent to visible light. The fit up of the door over the rest of the cavity is critical to keeping the standing waves inside where they won't be harming you. The plastic liner, glass shelf, and other decorative doodads are irrelevant and can be removed.

Metals are generally quite conductive and quite reflective to microwaves. Operating the microwave empty, or with a few pieces of metal (foil, silverware, etc) is bad because the standing waves will be very intense, having spots throughout the cavity of high field strength. Even though foil sparks and burns when you do this, relatively little damping of the standing wave is occurring. There will also be hot spots inside the magnetron, and it will overheat if you persist. That's why your instruction book says not to do this.

If you place something which absorbs energy (is lossy to microwaves) into the cavity, there will be a lot of power transfer from the magnetron to the lossy object, which will get hot. The intensity of the standing wave will be reduced, the oven will be able to run happily for a long time in this condition, and odd bits of silverwave and foil can also sit in the cavity calm and cool under this condition. The microwave frequency was chosen to make a strong energy transfer to water and fat molecules (food), naturally. The lossiness of other materials varies.

A good approach to heating a metal to a very high temperature would be to get a crucible which can stand the target temperature and is lossy at 2.5 GHz. There are certain ceramic materials which can do this. The crucible will get very hot safely, thus heating the things put into it. You will also have to set the crucible on a material which is an excellent thermal insulator, and is NOT lossy to microwaves. I would try (don't know firsthand) typical refractory materials such as kaowool. By the way, the temperature inside the crucible will rise WITHOUT UPPER LIMIT until the radiant and conduction heat losses from it counterbalance the available power from the magnitron. If your crucible is very well insulated, it is possible to reach plasma temperatures(!). You will need to adjust the insulation and/or heating time so that you only get to a safe temperature for your insulation.

I don't know the source for just the right crucible - only that this is how it's done.

The consequence of a bad door seal is exposure of yourself to a strong microwave field. This may lead to cataracts in your eyes. This was learned the hard way by radar technicians working on the fairly powerful radars introduced in the 1950's during the cold war.

Sorry for the rather long dissertation, but this is an area I know something about, and there seems to be a lot of interest in the idea.

[double_edge2]

please!.......do not put any thing but food in your micro wave. do not alter the faraday cage of the (open doors while running or rig to run open)the microwave.
i have worked with dc to daylight, and a fun toy they may seem for the short, 2400megs though not so short and a short half life, can destroy you or leave the beginnings of the end in you without you knowing.

please learn about more about the induction coil and the frequency they use for the proccess of induction forging.

any radiation is harmful! regardless of what university said it was fine to use your mobile or hand held two way.

buy an arrl handbook, and learn of some cautions first please!

you seem to have a fair understanding of this, to add, yes the right food presents the correct loading for this frequency....meaning most of the radiation is absorbed and turned to heat with the 2-5 min half life, not bounced as spurious and hamonics outside the faraday cages range.
when you start experimenting with materials not designed for this cabinet and cage you change the ratio between forward and reflected power ratio which can allow for wierd spurious and harmonics, more rf reflected/bounced to the insuficient cabinet that is not earthed enough to begin with and not designed for this type of use, and allow for unforseen events.

im done :)

Edited August 29, 2009 by double_edge2

[John B]

I agree entirely with the dangers of trying anything else but food in a microwave, the glass insert into the cross was done as an extension of an existing project, and should NOT be attempted without the equipment nescessary to allow it to happen safely.

Although this trial was undertaken it was done with a great deal of confidence due to using existing established techniques that gave it more than a good theoretical chance for it to succeed, and it was done knowing that it may not work, and the microwave may be destroyed (along with anything in the vicinity)

There is a safer way to achieve the same effect just using the forge.

[Walking Dog]

I also should have said more about safety. There are at least 3 serious concerns.

1) If you tamper/modify/damage the door, cavity, or magnetron, you may get a microwave leak which will be harmful to anyone in the vicinity of the oven.

2) The voltage/current levels in the power supply are lethal.

3) If you do get something in the oven to a very high temperature, you will need to handle it safely. See metal casting discussions for mention of the safety precautions needed for molten metals.

For most cases using the microwave wouldn't be very practical anyway. As John said, just use your forge.

[Sweany]

I promise I won't change the door, and I will stand 10 ft back. I'm pretty sure no harmfull xrays will be coming from my microwave.

[double_edge2]

yeh please, and a long stick on s/one elses microwave.:cool:

[Richfieldsmith]

um...i had a friend who put a frozen bottle of pop in the microwave to thaw it once. What he didn't realize is it had a layer of metal (i think aluminum) in the label.

He said the result was an unexpected light show inside the microwave caused by arcing, and a bunch of molten plastic plastered all over the inside of the microwave from when the pop started to boil and the bottle exploded. All in under 2 seconds.

It is possible he was exaggerating but i have no intention to find out. Microwaves are scary things.

That was from just a little bit of metal and an unmodified microwave. I wouldn't wand to be anywhere near a microwave that is filled with a handfull of iron in it.

EB

Edited September 3, 2009 by Richfieldsmith

[pkrankow]

Odd, I forgot to pull the wire off the Chinese leftovers yesterday, and the wire was cold, no sparks or fireworks, no scorch marks.

On the other hand, Mom's china is like the 4th of July or Chinese new years in the microwave! Mom put it in, not me.

I have also read some home made microwave popcorn recipes that use METAL STAPLES to close the paper bag for cooking. I haven't tried yet, but just got some GOOD popcorn (Tiny Tender) much more flavorful than the gigantic fluffy stuff.

Phil

[Richfieldsmith]

Could it be the type of metal then? What do you think was in the china that caused it to light up? I need to do some research I think.

E. Benz

[pkrankow]

The china had gold and silver trim on the edges. You could see where it burned away after the nuking. Both colors of metal were affected, I say colors because I do not know the alloy.

Other plates, stoneware I think, get hot because of water trapped inside the ceramic.

Phil

[Jack Hirsch]

Hello everyone after watching a youtube video by Shake the Future about his microwave kiln (he was supposed to release a how-to months ago but has disappeared since), and his microwave smelter is incredibly interesting as he is able to melt cast iron in it (I know not really practical but it looks cool). Does anyone know how he makes it? 

[George N. M.]

Given the rather spectacular effect when I put a gold rimmed plate in a microwave once I wouldn't try it with a good microwave.  If I wanted to try it I'd get a cheap/used microwave and set it up outside with a way of turning it off from a safe distance, e.g. unplugging it, full PPE, and a fire extinguisher handy.  This is NOT what a domestic microwave oven was designed for and would probably exceed all known safety limits.  The reason the poster has not released another video may be that he is still recuperating from a disaster or someone had a long talk with him about liability.

The more I think about it I'd give it a hard pass.

"By hammer and hand all arts do stand."

[Steve Sells]

I cant imagine how a microwave smelter could work, how do you feed the ore when its operational? where does the dross bleed off too? so many problems there

[Buzzkill]

IIRC these types of machines use the transformers from microwaves.  They rewire the transformers with some very heavy gauge wire and only a few coils and then use electric arc for *melting* not smelting.  I've seen a few videos over the years that are similar, but not sure if any were the specific one referenced. I've never tried to replicate any of the items myself.