I have a smallish air compressor pump I rebuilt, and just picked up a tank (DeVilbis) that had a dead compressor on it. I need to weld an additional pad on the top of the tank to take my motor. Any special precautions needed for welding to a 150psi rated tank? I'm guessing 1/8" E6013 or E7018, since they don't dig much, and low amps, and short-spaced and/or back-stepped beads not more than a couple of inches long. Can I reduce any introduced stresses with a little pre-heat? A burst compressor-tank can knock a wall right out of your garage!