Homemade Incubator Temp fluctating too much. HELP!!

[Vnctan]

I made a homemade incubator out of plywood with a plexiglass door, a 150 w light bulb, and a water heater thermomstat. The only problem with it is that the temp is fluctuating too much. It goes all the way down to 93 degrees before it turns on and goes up to 110 degrees before it turns off. I'm going to be using it for duck eggs. I'm using the same water heater thermomstat that everyone who make their own incubator uses. What am I doing wrong? Has anyone else had this problem with it varying so much?

 

[Daidohead]

If the thermostat is mounted tight to the wall it must wait for the wall to heat and cool, kinda slow. If you put a couple of spacers behind the mounting bracket it will allow air to get to the sensor and may speed things up. It worked very well on mine with just a 3/8" spacer. It takes a while for them to warm up but do very well once they get there.

 

[MissDeb]

Daido,

I did that and also mounted a metal plate behind mine and it still fluctuates from 95-100

I think what we are going to do is to mount the thermostat backwards so that the plate on
the back of it will face outwards. Then have a little hole in the side so we can adjust it without having
to open the bator. Maybe moving it closer to the light would help too? It's on the other end of the cooler....

 

[Daidohead]

Quote:
I think the individual designs vary so much that it is just a matter of finding what works. I started with my thermo close to my heat source and it just cycled on and off way too much to suit me. I have 6" between my thermo and heat source, with a 25W bulb and a 2* temp. swing. My bulb is on for 5 min., off for 10min.

Here is a pic of my set up.

 

[MissDeb]

Nice!

 

[Vnctan]

My incubator is plywood about 15" tall x 16" wide x 15" long. It is still air at this point but I have a fan I can install I just didn't because space was an issue. I have 3/8" weatherstripping around the door to seal in heat. I have three 16 oz water bottles for heat sinks. My thermostat is only about 3 inches from the 150 W bulb and it has a 1/2 space behind it to let in air. I have no idea what I'm doing wrong. My humidity is around 60%.

 

[MissDeb]

I hear most folks only use a 40-60 watt bulb?

 

[mitch324]

I would try a smaller bulb.