Putting older posts here. Going to try to keep the novice forum pruned about 90 days work. The 'good' old stuff is going to be put into appropriate forums.
I was honing my brazing skills last night on two scrap pieces of .024 copper. After silver soldering the joint I turned the now conjoined pieces of copper over and discovered that what looked to me to be the top layer of copper was black and flaking off. Is my Mapp/oxy torch too hot? Will this issue effect the integrity of my still? If not how do I remove the grimy black film?