Charcoal Smoker Modifications

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Smoking Guru
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Jul 7, 2005
Midvale, UT
Folks, Here's your chance to post the modifications and (hopefully) pictures of what you did to your smoker to make it work better. This topic will remain as a sticky so all the new folks don't have to hunt to far to find it.
I got tired of having to watch the smoker to prevent runaway temperatures. I went to EBAY and bought an old bimetallic spring assembly removed from a 70s Volkswagen Beetle Solex carburetor. It's a spiral spring that works by opening the choke as the engine comes up to operating temperature.

What I wanted to do was set it up such that this spring would actuate an internal flapper on the chimney from inside the silver smoker. The plan was for the flapper to be normally open, but to then close off the chimney outlet when the temp gets too high. Theory being that if the chimney is closed, the fire is "choked" and will die down (or at least the fire can't vent through the smoker very well, allowing the chamber to cool a bit as a result).

A little sheet metal for the flapper and frame, coat hangers for axles and actuator rod, and washers for a balance counterweight and you can see the result. As you can see from the photos (hope Iâ€[emoji]8482[/emoji]ve attached them correctly), when the bimetallic spring assembly is rotated to the correct position, the hook on the outer edge of the bimetallic spring will catch the tab on the actuator rod, pushing down on the actuator and holding the flapper open. When the temp rises the spring will back off and allow the counterweighted flapper to return to its default position and close off the chimney. I set it up such that I can calibrate the flapper to close at any value between about 150F and 350F.

I'll see how this works in the long run. My concern is that the bimetal spring will get too filled up with residue and jam up (failing in the “open†position). Might have to clear out with a little carb cleaner from time to time.
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