Today I built a three-legged support structure to hold the beer fermenter. My original design called for welding three square cross-section tubes to the sides of the conical tank. I decided against this method because I wanted to ability to remove the tank from the stand, and I was also a little worried about having inadequate argon coverage on the weld backside (in the tank).
The three legs are only held together by the welds near the ground. The tank just rests on top of the legs. I may add some strapping to prevent the legs from splaying outward from the conical tank, but so far, this doesn't seem to be much of a problem. The legs are all 304 stainless steel - same as the tank.
I was surprised how little filler rod I needed for these welds. Next time, I will make my tack welds much smaller, because the weld bead itself was very tight, and the globs of filler from the tack welds were annoyingly large.
I welded some stainless nuts to small sheet metal structures, then welded the assemblies to either side of the copper heat block. The two nuts will allow me to sandwhich the Peltier between a large heatsink and the copper block. I'll use nylon screws to prevent heat transfer and also to make the compression on the Peltier more gentle and balanced.