Never! Any machinist with even half a brain will not wear gloves. Gloves are very tough, they get caught in the cutter your fucked.

The idea of water cooling an antminer may be a good one, but only if you put the radiator outside, or use well water and discharge it back into the ground. You could also use water from a stream or pond on your property. Just to get the heat out of the building, especially if you're running a few KW of mining equipment.

I would use 6063 aluminum alloy or similar, failure from corrosion would take much longer than an antminer will be worth running, unless your pumping saltwater through it.