jimdoc said:
I plan on using this 6 grams to experiment with getting into solution, and when I get it right I will do the rest of my wire and make an ingot or bar. Do you have any tips for that? I have read about palladium absorbing oxygen,sounds like I should stick with gold to learn casting first?
Thanks. Jim
I've commented on this before, but to this point it hasn't been an issue.
Understand that the platinum group is very unlike gold in that it will NOT precipitate well, if at all, from dilute solutions. Even then, it often will not precipitate completely, so your processed solution will still test positive. You may have to recover the traces on scrap metal and include the black powder in a future batch.
To precipitate, you'll want your solutions as concentrated as is convenient. If you've not done any of this before, I strongly recommend you read Hoke on the recovery of palladium.
I didn't melt much of my palladium, although I melted enough to know how it reacts. I simply calcined the salts to sponge, and stored the sponge.
Palladium, unlike platinum, reacts with oxygen readily. You'll see that when you calcine your palladium salts. They end up covered with the most beautiful peacock colors of green, blue and red. Hoke suggested that a fast wash with alcohol prior to melting would reduce the oxides, which I tried. It wasn't real obvious that it was effective, but I achieved respectable results in melting to a button.
I simply torch melted what few times I did anything with the palladium sponge. I allowed the button to form in a melting dish and removed it after cooling enough to set, but before the partially melted dish glued the button down. The button was then pickled with acid to clean it well. to be perfectly frank, I do not recall what acid I used, but for platinum, HFL was used, in a platinum container. It should be avoided like the plague by those that are not well versed with handling acids----it's a killer.
Aside from one tiny button that I will, hopefully, include in a future picture of the various states of palladium, I no longer have any of the buttons, and only a small vial of the sponge. It was all sold some time ago when palladium went up in value.
I recommend you do not try to learn about casting ingots with palladium. For one, you're not likely to encounter enough of it to gain much experience, and it melts at, roughly, 850° higher temperature than gold does (I'm trusting memory here, so I could be off a little). It's not pleasant to melt, unlike gold. You might consider simply creating buttons, as I did. It's the course of least resistance, and adequate. I'd suggest you investigate the high temperature melting dishes provided for the jewelry industry for melting the Pt group. Those nice little clay dishes I recommend for gold aren't an acceptable choice because of the high temperature involved.
Harold