Der Ami. My feeling is you would try to talk this subject to death or failing that until our King Henry the Eighth forgave Ann Boleyn for sleeping around.
When you are given a set of barrels you have no Idea what type of solder is used just stating melting point temperatures does not make them a practical cast in stone fact for the barrel or barrel you have in your hand. So I will repeat DO NOT PUT VINTYAGE SIDE BY SIDE BARRELS IN THE TANK THAT USES THIS BLUING FORMULA!!!
Stop throwing chaff in the air in a vain attempt to justify what you have said. You should remove all residues be them solder or oil or anything else for that matter from any metal you put in a bluing tank if you dont you will contaminate the bluing mixture, after all it is not a cleaner. I have no idea where you get your information from but it leaves a lot to be desired.
