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> That said, I wouldn't melt metal in an expensive microwave. The metal has poor absorption relative to the magnetron antenna itself, so both will heat. I wouldn't be surprised if the antenna is also glowing a bit (at least early on)!

You don't make the metal absorb the microwaves. Either your crucible or the inner lining of your insulator will be designed to do the absorbing.

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Ah, well I'm guilty! The videos I saw, in the past, were just a ball of fairly fine wire on a plate. This was probably 20 years ago, when I was looking into melting black beach sand in the microwave.

For a rant about that, it turned out pretty neat. I put the beach sand in a thin layer on a dinner plate that was a half wavelength above the bottom of the microwave, turntable removed. The beach sand would start to melt where the standing waves were, but then quickly grow into a wire structure, with the growth of the tips driven by where absorption would be maximized, allowing the thing to heat more, and grow more. I tried to model the resulting "antenna", but none of the open source tools at the time could handle the complexity.

This was a wonderful little read, thank you!

As was this, thankyu sir

> the inner lining of your insulator will be designed to do the absorbing.

That is exactly the case with our setup.

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