I've been looking for a place to give my tub an acid bath and was thinking of doing the frame too. I found a place that could acid dip my frame, galvanize it and powder coat it. I'm awaiting a price quote from them. Would being dipped into 850° molten zinc warp the frame at all? I was thinking I could possibly make some braces that bolt into body mount holes to hopefully keep it straight. Unless it would still warp anyways. I'm not sure if I want them to dip my tub because their process was designed specifically for metals to be galvanized. I'm pretty sure the tub would warp from that.