I have been tig welding for years...make sure to remove the coating, even aluminum. Any kind of coating will gas off, and in some cases make you sick or can kill you!

Galvanized coatings will cause lung cancer...I know two people that died of cancer from breathing gases off of welding. Beryllium Copper will kill you dead very quickly.

Take the safe way out, always remove any coatings.

My 2 cents, Mark