I was thinking more along the lines of swapping out the LG thermostats (wafers and solid) for a more accurate type.
Ok ... take a look
here
This is one I built using a Ranco. I was lucky, I have an old freezer that I use to brew beer and I had the Ranco to control it. I have the two stage version.
The problem is that the Ranco costs more than the incubator
The other problem is that better can be had cheaper. I used the Ranco because I had it, and results were excellent, but in my never-ending quest for perfection I have found better, cheaper.
The Ranco, like all the other electronic thermostats is an on/off controller. It just happens to be a very high quality one that is highly adjustable. For incubator purposes it is just fine, but the 2 stage is overkill.
Better would be a PID process controller from
Ebay, with a T-Type thermocouple. That's what I plan on trying next.
The contoller will be around $50 shipped, and the thermocouple about $15
The benefit is in the method of control. PID controllers have 3 settings. On/Off, proportional and PID. The proportional is a burst controller that aims to replace measured heat-loss by rapidly cycling the heater.
Brinsea uses them, as do R-Com. They are very stable, esp. in stable ambient temps.
PID goes a step further, and uses proportional control while, at the same time, measuring the change in ambient temperature and allowing for it.
It's probably the ultimate control, and would allow an incubator to be used in a barn or shed (not the LG, the heater isn't big enough)
Food for thought, come on back if you have more input.
Steve