the vinegar etches it - like it does w/ any metal, and even concrete!! eek potent acid - I wouldn't worrry about the inside, that's prolly the kinda residue that ya always see on zinc coatings, and the gas will take care of it! grin

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature we find it attached to the rest of the world" John Muir
"When we tug a single thing on an old truck, we find it falls off" me
Some TF series details & TF heater pics & Rust-a-holics Unanimous parking lot