microwave smelter

Step 7 Pour ingots

If all goes well, after a few minutes you'll notice that your crucible has heated up and smelted the metal. Grab your crucible with tongs and pour it into your mold. I used a cast aluminum pancake mold found at a local houseware store. The melting point of cast aluminum is 660.32 °C (1220.58 °F), well above the molten temperature of the lead/tin and silver solder.

Pour molten metal into mold and allow to cool, then gently tap reverse side of mold to release the cast ingot.

Comments

[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.

[culinaryoverlord]

I have worked with all the metals mentioned here, hell, I can alloy you a low melt babbit that will melt in a cup of hot coffee. There are a few good points among the bar-de-bar-bar in this thread too. The metals are toxic, and precautions should be taken, but staying upwind should suffice.Get some bismuth and antimony in there and you could have much better results, and much more possible toxicity The alloy would be more able to take the detail. The alarmist folks really outnumber the risk takers here, nothing wrong with ringing the bell, do it too much and people stop listening.

[dr2chase]

Was that aluminum coated with anything? Is that an anodized surface, or something anti-stick? Teflon is supposed to start degrading at 500F, and decompose at 662F (Wikipedia is a little vague on this -- "pyrolosis ... is detectable at 392F").