I have a lincoln tombstone ac/dc welder. What would be the best way for me to weld aluminum. I have an old airco 300 amp water cooled tig torch and a homemade water cooler I made from a bucket and pond pump. I been running on dc- under 180 amps with no overheating problems. Could I tig on dc+ without killing my pump or would the power backfired into the water causing problem? Or just aluminum stick it?