And other metal melting techniques:
Propane melting furnace using cheap YTONG blocks as refractory
Propane melting furnace with larger capacity made from Mizzou concrete
Homemade optical (disappearing filament) pyrometer
Potassium chlorate making electrolysis
Punching hemispheres with dome punches and block
is a device with usually hemispheral dies in it, made of hardened steel (sometimes of brass or even hardwood) intended for making hemispheral shapes from sheet metal. A
is a globular punch to force sheet metal into a globular shape by giving it a hammer blow on the metal sheet disc which is laid in a dome block die. I use sheet metal of 0.25mm thick in a disk shaped 22mm diameter to get a 16mm diameter sphere. I just cut this out of sheet metal. Punching doms of silver or other malleable metal requires some experience. The problem is that the edges of the dome can be damaged when putting into a smaller die of the punch block.
Fortunately, all errors made by damaging is not a waste of material, as I just remelt them, pour it into a small slab which I rollagain into sheet.
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