So I have been experimenting with adding an automatic control to my Ideal Steel. What you see in the picture is the primary and secondary inlets at the bottom of the stove. Both openings change when you open the main air control. They are being regulated by two bimetallic strips being held up by magnets. When you open up the draft, the cool air rushing in bends the strips to open. As you close the draft to 1/4 (base setting for my testing) the strips close as the stove warms up. This sends the stove into a blackout cat burn. The cat takes over and the secondaries disappear. Hours later when the cat starts to cool off the controls begin to slowly open allowing air into the coal bed to maintain the temperature. It never allows more air in then your base setting (1/4) so it can't run away. Last night was my first run with this setup. It was very successful. The box was black when I went to bed and I had red coals glowing and mostly clean glass in the morning with plenty of temperature to the stove. Usually if you close the air completely on this stove it will burn hot for a few hours then cool off fast. This way my base setting is basically for a medium burn but is automatically regulated down to a very low burn. I will continue to tweak and test it. The first picture shows what it does at wide open throttle. The second picture shows how it reacts to 1/4 open. Also, this setup does not interfere with the main draft control operation. You can move the air control throughout its entire range and the strips are not affected.
I don't completely understand since I don't have an IS to look at, but it sounds like an interesting experiment. I might mess around with the air a bit on the Dutchwest to try to get a more even burn, like what you're doing. Right now I have to open the air a bit as the burn progresses. First I will try to see if I can adjust the air wash since the load is burning hotter on the right. If I alter the stove, it could be something as simple as drilling a small hole in the ash pan housing, like BDF did. [The Keystone comes from the plant with this hole.] Right now, I'm playing around with how I load the box, such as putting some faster-burning wood in the back, or putting slab-like splits in the back and standing them on edge. More or less ash left in the back may affect how fast it burns back there as well...
I seem to have tapped into the sweet spot of this stove. Even when the strips are closed I am getting a very even long cat burn. When the strips are closed some air can still get by. I think there would be a way to cut out their air control pattern for a better low end burn. When the air control is fully closed maybe drill a hole in the primary plate.
