Hey everyone. i decided to remelt my chunk of gold into a button to test my new torch. it was really shiny and smooth before and now it looks like it has a rough surface. i suspect it to be impurities, but i dont know why the original chunk didnt have this look. has anyone had this happen before? the close up pics are a little off on the color because this is my cell phone camera.
is this normal?
- Thread starter kronix
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I suspect your right about the impurities and I'd also suspect you didn't get the metal fully molten and you didn't flux your dish.
Geo
Well-known member
yep, looks like some kind of oxide to me. dont be afraid of the heat, it only takes a few seconds at white heat to get a good melt.
I used a fused silica melting dish with borax as a flux and i got it fully molten and held it there for a few minutes before i let it solidify and then i grabbed with pliers and dipped in water to cool it down. i did it twice actually and even tried to just melt the surface to make it smooth.
Geo
Well-known member
impurities become part of the metal matrix. its not just on the surface. if you polish it and the remelt it would still look like that because the impurities rise to the surface and oxidize. you will have to refine it again. take care to use dedicated glassware to precipitate, wash and rinse per Harolds instructions, use a clean melting dish, be sure the torch tip is clean and free of dirt and contamination.
Geo
Well-known member
too, it looks really lumpy. like it didnt melt really well. im not saying it didnt, but when i melt, it gets so bright i have to wear welding goggles.
