Be careful with that! I've been messing with the grinders and it seems like theres still some work to be done on it. max grind items dont seem to keep their grind and I just tested now with almost max grinded weps, half max grinded weps, and just barely grinded weps... same thing... they lose their grind in bank.
Next test will be to max grind then use a wep a while... see if maybe it needs to somehow "stick" that way? i dunno