Dear Orchid members,
It’s my first post here, although this forum is my go-to resource any time I get in trouble . Usually I find the answers without asking my own questions, as there is a lot of info available.
This time I was not able to find anything, not saying it’s not there…
So, I am trying to fuse Pt dust to 18k gold with little success and I was hoping maybe someone could point me in a right direction.
I am using 999.5 Pt filings, which I make with a Vallorbe #2 needle file and 18k gold sheet, 0.6mm thick, alloyed with 12.5% silver and 12.5% copper. I paint the spots on the gold with a solution made of gum tragacanth, hard flux and distilled water, roughly 1/3 of each. I sprinkle platinum dust on top of the painted areas and leave to dry.
I get the gold to sweat under the Pt dust with a Little Torch, oxy/propane with #5 tip, slightly reducing flame, by brushing the flame on the surface for a longer period of time.
After the gold sweats I leave it to cool, quench, pickle in warm sodium bisulphate solution and the Pt just won’t stay on. I try to time my heating such that it is the maximum possible without melting the gold base plate, but it’s just a subjective judgement.
I have roughly a dozen failed experiments and one that was successful, but I could not replicate further, although I was using the same setup.
Any ideas on what I could try next would be highly appreciated.