Friday, July 27, 2018

a friday night film


John Wells said...

Melting down sterling silver flatware and casting ingots. I needed to mill a new graphite mold for the project. The tiny furnace heats the mold up to about 1,800° using just a propane torch. I can only get about 10 -15 casts out of a mold before it is destroyed by the high temperatures and the force of the torch flame. Sterling silver is an alloy of silver that consists of 92.5% pure silver and 7.5% of other metal, usually copper. The alloy is harder than just pure silver. It is interesting to note that the melting point of pure silver is 1,761°, but the melting point of sterling silver is 1,640°. I had to add a little extra sterling silver I had on hand to cast six 35 gram ingots from these pieces. A troy ounce (the standard used to gauge the weight of precious metals)is 31.1 grams. A standard ounce is 28 grams. News Theme 2 by Audionautix is licensed under a Creative Commons Attribution license ( Slow Tango by Andrew Haung used by permission from the YouTube Audio Library.

Robert said...

I see you don't use a crucible but the graphite just curious but why? I have smelted pewter in a forge and poured it but the temp is of course lower for pewter
It's all good fun too . When I was a kid I used to draw so the etch a sketch was somewhat of a mystery then one day while using my mini mill (it's sometimes boring ) I had an Aha!! moment . I'm simple like that he's sir and that steam engine never got done.

John Wells said... is really difficult to pour an ounce of silver unless the mold is already heated red hot. Might as well just let the silver sit in the mold until it gets hot enough to melt. The melting point of pewter to pour is less than 600° - sterling silver has to be about 1,700°.

David Johnson said...

Nice job John