There is a product on the market called Cupronil that prevents fire
scale when soldering. It works very well. Clean and polish your
silver piece before soldering. Warm silver and spray on Cupronil
till it coats all surfaces. Once the silver is coated solder as
usual. Coat the silver each time before soldering. no fire coat!!!
fire scale!!! or that.
Lee, I’ve been using Cupronil for years, originally for silver but
now for all my gold soldering as well (hate the green stuff) and I
love it too. BUT … If you overheat the metal enough to burn off the
Cupronil, you will get fire scale. Trust me, I’ve done it! And
despite a good, even coat of Cupronil, which is imperative. If you
don’t overheat the metal, on the other hand, you’re right that you
won’t get fire scale and I find Cupronil far more effective than boric
acid/alcohol plus conventional flux.
Thanks for the heads-up on Win-ox.