What is revere ware copper lacquered with?
I don’t beleive any coating was placed on the “vintage” copper bottom RW. I know of know coating , certainly no coating that would have been economical or even available in the 30-50’s , that would not char and make a nasty mess when exposed to dirct flame. If any coating was ever applied it was probably only put on at the time of manufacture as a temporary coating to prevent oxidation of the copper until first use – possibly a paraffin or plant based wax originally , maybe a silicon in later years. I wipe the copper bottoms of my RW with a sponge pretty well soaked with dishwashing soap. This will keep the shine from oxidizing and also makes the bottoms easier to keep clean, especially if you use a gas stove.