I need some help getting some silver solder to adhere to sandblasted stainless steel (aluminum oxide blasting media I think). I have 304/316 stainless plates of either thickness', 0.030 or 0.060 and I'm trying to get some solid copper wire to solder to the plates for electrical connections. I started with my digital soldering iron at 750F, but didn't get the electrical 60/40 solder to stick very well. Then I bought a 230W soldering gun and it worked better, but still not good enough. I bought some Harris High Temp Black Flux and it just dries out before anything will stick. I grabbed some miuratic acid as well and tried a drop on the stainless but all it did was make the metal black and the solder roll off worse. I bought some Solder-It Silver solder paste and it doesn't work either, everything just rolls off the stainless or if it does stick I can't get it to wet in the groove for the copper wire so that I know it joins good.