I want to sweat solder a middle-sized piece. I started to melt the medium solder pallions. Strangely on one part of the silver surface all the palliums balled up.
I sanded the piece to have a flatter surface and then rinsed the piece with clean water. But even at a second attempt the pallions don’t melt - on the rest of the piece they do. I used lots of flux but to no avail. Can someone please explain to me why the melting of the pallions is so uneven? Thank you very much!
There are lots of reasons why this might be happening and you appear to have tried to remediate most of them. Dirt is the usual reason why solder balls up and won’t flow. It’s possible that just sanding and rinsing isn’t removing all of the dirt. You might try a degreaser too. There may also be firescale in this area. Firescale can keep solder from flowing. If it were me, I would clean the entire piece with a degreaser. Heat it up and pickle it again, coat with boric acid and alcohol, burn off the alcohol, flux with a heavy borax flux and try again. These things are very frustrating. I use a lot of boric acid and alcohol and borax flux and it seems to make my soldering a lot easier and more successful than commercial liquid fluxes. Good luck and keep us posted…Rob
Thank you very much Rob! I’m proceeding as you say. I will keep you posted!