Wellall the things I have done with metal in my life and been lucky enough not to get hurt there is another aspect of the work I do. I went to a technological university in Oregon years ago and took machine shop and welding. I had to take other classes too but that was my main reason for going. So when you know how to weld then doing soldering is a piece of cake. We learned how to use the acids to clean metal and all so as to make it work better. With most steel you have to use an acid called Muriatic Acid that is so bad it will eat your skin off. This is the only thing they use to clean brick when they build a brick home even.              Well with copper and stainless steel all you need is RUBY FLUID it is a pinkish color and it will not eat the skin off but safer to not wash your hands in it. It cleans the metal so the solder bonds better and on cold copper I can change the color of the copper by brushing it on and leaving it. the Basic Soldering Kit consists of 5 sticks of 50/50 solder a pint of Ruby Fluid and a cleaner block yo clean the tip of your soldering gun. If you heat the copper it will turn blue and purple by how much you put on it but you must clean it or the solder will not work. I would not advise using any other type of acid to clean your metal.

copperdan

Zirconia, NC