OK, so why is this in the “what not to do”? Because I think we’re about to find out why these thin drums are a very bad idea. They are light, sure, and moderately easy to build. But particularly here, in the always-wet hay filter, I don’t think they will last much more than 18-24 months
What else can be done here? Thicker metal would last longer, but will eventually rust just the same. Still, I would recommend using a water heater over these thin drums.
Pesonally, I’m planning to experiment with plastic. I think the temperatures are fine, corrosion is a non-issue, and it should last indefinitely, if taken care of.
I’ve ordered two of these 15 gallon drums: http://www.newpig.com/pig/US/nut-bolt-ring-open-head-colored-poly-drum-drm772
I plan to stack them up and weld them together. Adding fittings will be a challenge, but not impossible. Plastic welding is actually quite easy. Here’s the kit I got:
Plastic welding can be useful on other areas of the gasifier, I’m pretty sure. For instance, instead of taping over those wiring holes on the blowers, I plan to weld them shut, and redrill smaller holes if needed.