i have an old timer knife that is not stainless steel.i bought it for my son last year.the knife looks like it is rusting already but the residue on there doesnt even look like rust.ive seen knives that look like this before and im sure some of you know what im talking aboutwhen this first started i thought this was blood he didnt get cleaned off but it wasnt and just continued to get worse.i have another knife like this that i dont use ofter so it isnt happening to that one.how can i stop this from happening and what can be done to fix my sons knife