Well, it prolly wasn't, sand it back down, get a nice magnent you know is strong, try sticking it to the stainless, if it attaches itself well, theres your problem, magnents don't stick to stailness steel, you can judge quality of stainless with a magnent, by if it does stick, how hard does it stick, you need a strong magnent and test it with regular steel to be shure of it's magnetic power, then you can test quality, if it sticks compleatly, not stainless or stainless coated ( like some cheap stainless sinks ), sticks a little, could be a good coating or cheap stainless, dosen't stick at all, good quality stainless. Stainless don't rust, unless it's not really stainless.