How can i focus a magnetron beam from a microwave , to make a small metal forge?


I have been looking for a number of ways to cast my zinc with, along with just melting other metals namely aluminium.
I have come across the microwave method, however i feel that just using a microwave is a wasteful and hazardous means of meting metals like zinc , since the metal vapors are very flammable, even explosive, even as a dust

I thought, since the microwave is basically just a box which the magnetron beams microwaves into, why not build a forge, which consist of a crucible laying in the center-point of a magnetron beam. all this would sit outside, done at a distance to avoid exposure to rouge microwaves.

I dont wish to introduce anything new into the equation, just use prexisting things form the microwave, and probably some aluminium sheet.
Anyone know if it will work better than just using a microwave? and how i should focus the beam? i want to keep the whole thing as compact as possible, probably which the crucible being no further than 10-20cm from the magnetron.


While I, personally, have never used a microwave to melt metals, I have head of someone using a microwave to smelt iron ore. http://www.thomasthwaites.com/the-toaster-project/

Not sure about zinc... I suppose with adequate ventilation the fumes will be nothing to worry about. And wouldn't the crucible be effected by the microwaves as well?

Hopefully that helps a little bit!