My first question here - please be gentle with me (I've already tried the Search function).

I've been a good boy (I think)...
  • I bought a decent sized (Orca) torch, so I could heat the Silver more quickly than I could with a hand torch.
  • I've reduced the amount of air in the flame, so that flecks of yellow are visible and the flame is more 'roary' than 'hissy'.
  • I solder on a charcoal block. Every time.
  • I try my best not to overheat the Silver. I hold the flame on the join for 1 second after the solder has melted and then take it away.

...and I still get some firestain (although not as dark / deep as I used to) - even on simple pendants, with just a single jump ring soldered on for the bail.

Then I read that firestain can be 'brought out' by the frictional heat generated in the polishing stage and I think this may be what's happening (we use Tripoli and Rouge in our classes). It started appearing again yesterday, on a small batch of simple pendants, at the polishing stage, so I held a couple back and polished them at home with finer micromesh grades and fine 3M radial wheels. Guess what? No firestain.

For my next steps, I'm considering...
  • Abandoning the coarse wheel / Tripoli in favour of micromesh, then finishing with rouge on the soft wheel.
  • Checking out boric acid, or some other proprietary solution, as a preventative (suggestions / recommendations sought).

Does that sound like a plan? Any suggestions / constructive criticism welcome.