well you would think its more complicated then mixing sand with silver to make a putty to smear into the PCB, that is all he does. the laser cutting is optional
its like the easiest way to make a single sided PCB if you have the stuff I think, since its just the stencil, there is nothing else.. no photoresist, etching, etc. All those processes are quite tricky IMO. Looks like the apparatus might be a coil taken out of a electric heater laid around some firebrick
I thought you would need some 4 letter acronym organic flux magic binder chemical that costs 1000$ for 1g, is toxic, noxious, has a 3 week shelf life and is only sold to chemical companies... but its just fine sand and silver powder. The dangers of the refractory temperatures make up for all the good parts of this, but still.. that is just a question of being patient, there is no reason you can't fire it, leave it alone for 24 hrs till its room temp and never deal with anything hot at all.. so long you have discipline. more safe then chemical baths IMO. And the fiberglass dust is replaced with silica that is likely so fine it will be exhaled. I thought the sintering process required some 'insane industrial stuff'.