So this card is a second hand Zotac 1070Ti Mini, i got it for a really cheap price (ofcourse it's because of the white stuff and the copper pipes being worn out). I don't really know the environment it used to be in, but i thought that i could clean the white stuff and polish the copper pipes. I tried using a brush and some metal solutions, alcohol, etc, but nothing works (the copper is now shiny tho). I've also changed the thermal pads and paste, now the temps are 55-70ish and the card works fine. I just can't figure out on how to get rid those white stuff.
Sorry bad grammar
I see. Have you any reason to suspect this card could possibly have been used in some mining operation? I've known of people renting warehouse space for mining and sometimes not ideal environmental conditions. The cheap price has me suspicious. Anyway, only other thing i can think of is to use a polishing attachment on a rotary tool like a Dremel. I am assuming it functions well and its great that you changed the thermal paste.