First, HEED the warning of inhaling fumes. It WILL burn your throat and nasal passages if inhaled too much! So, be careful. I inhaled too much of the fumes, and I had pharyngitis as a result. Couldn't speak for two days..that's how bad it can be, and I was lucky I didn't burn my lungs. It's extraordinarily dangerous when you don't wear protection. It can also cause eye irritation. I'd say that you should probably wear protective goggles, gloves, and a respirator mask, especially for big jobs. I had a big job and therefore I was exposed to the fumes for too long without protection. I'm not exaggerating, it's harsh!Secondly, this didn't work well on old stainless..but it worked great on old brass.