After building the Franken-bator, I was pleased at how well it held temperature. It seemed like it was working well.
However, I noticed that it was not retaining humidity as well as it did before. Prior to gutting it and adding the Incukit Mini to it, all I needed was one or two wet sponges to keep the humidity above 65%. After, I couldn't keep the humidity above 45%, even with all the water wells full.
My first step was to assess my hygrometer to make sure it was accurate. To do this, I put some salt in a bottle cap, added water until the salt was very damp but not covered in water, and put the cap and the thermometer/hygrometer in a clear sealed container.
After 6 hours, the humidity inside the container will be 75% and how much your hygrometer is of that number, is how much you need to adjust when reading the humidity. Fortunately for me, the hygrometer is very accurate. So the problem is the incubator.
The next thing I decided to check was if there was too much air and humidity was escaping from the holes I put in the incubator box to make room for the Incukit and it's cord.
So I took a Ziplock bag, cut a square out of it, and taped it over the holes in the insulation on top of the lid. This immediately fixed the humidity problems. There was too many air holes that was allowing the humidity to escape.
The next couple of weeks, everything went fine until we had a heat wave that pushed the temperature into the upper 80's for a week in April. During this time, I noticed that several times the incubator thermometer was reading low temps (97 degrees F) and the internal thermometer/hygrometer was reading temps in excess of 103 degrees F. What I discovered was that in an attempt to keep the thermometer at the level of the eggs (the black wire hanging down from the middle), I was allowing it to slip down into the water wells underneath the eggs when I shut the lid. This tricked the thermometer into thinking it was cooler in the incubator than it actually was and quite a few of my eggs got cooked.
My solution for this was to loop the wire up into the fan guard and bring it back down so it would only drop down as far as the level of the eggs.
After that, I noticed that the incubator was still holding at high temperatures for a long period of time and not cooling off as it should. The solution for that has been to remove the insulation from the bottom of the incubator to allow for more heat to dissipate now that the air wass warmer.
I still have a few kinks to work out of the system, but I don't currently trust it to maintain temperature for starting eggs while it is so warm this summer as I have no AC in my house to maintain a steady temperature. I've gone back to using it as my lock down incubator and starting my eggs in my Brinsea Ovation 28 EX.