As promised, my first incubator

[Stockwell]

Hi Ryan and Trev
Ryan, yes my incubators as you know are all constructed of plywood, and are in the 3 to 4 cubic foot range.
I only use a maxium of 4 1/8 inch soldering iron holes in each egg box... usually one in each corner of the lid.

Trev
Yes, Heat tape is what I currently use in all my incubators. It has the advantage of
distributing the heat very evenly, and this is actually an improvement over most other heat sources. Even without fans, there are no major hot spots in incubators using heat tape.. Fans of course mix the air constantly, and makes hot spots a complete non issue. It's critical to use low power low RPM fans, otherwise they will contribute to heating the box, and standard Radio Shack type computer fans move too much air.... Fans around 5 watt moving a mere 18 to 30 CFM is best.

You can screw the heat tape to a board, or silicone it to a piece of plexiglass.
I recommend elevating it slightly off the bottom just in case some water does end up in there...you don’t want your heat tape or any connection to it, sitting in water...

Just keep in mind you need only 5-10 watts of heat per cubic foot of incubator volume, in order to raise the temps 20F above ambient.(70 room temp to a max of 90 for pythons=20F)

A 30 watt element such as those in the hovabators is actually a little more power than is really required for our use with herp eggs.... You must remember that hovabator elements are for chicken eggs which are hatched just under 100F, so they must elevate ambient by 30 degrees F where we generally need less than a 20 degree rise

20 watts would be loads for a typical fish size styro.... Using 4 inch 8 watt heat tape, that would be 2 and a half feet......Should be no problem.I'd start with 2 one foot long pieces and lay them side by side the full width of the bottom... I think 16 watts would do it...

If you're using a big camping cooler or other wooden enclosure, then simply determine the cubic feet volume(LxWxH) in inches,divide by 1728 and do the math to figure out how many feet of heat tape you will need....10 watts per cubic feet of air, is easy to remember. In most cases, a little less will actually be fine.
The way to test for this is set the unit up, and see how long it takes to reach 90F from a room temp of 70F
If it runs longer than 20 minutes before reaching setpoint, you better add another strip of heat tape..(this is my personal test criteria with wooden boxes with sliding doors)

Also worth stating, is that too much power will cause the temp to increase very rapidly and over shoot your setpoint causing wide swings in temperature.
You want to avoid that… and must remember it takes time for everything to heat up and it takes time for the metal in the thermostat to respond…

Have fun building!!

[BoidKeeper]

Good stuff Roy.
Thanks,
Trevor

[Scales Zoo]

Roy, ever considered writing a book like "Tidbits of info learned in 25 years of herpetoculture, and I've lost the hair to prove it"

I'd read pages and pages of your general rambling - I've learned so much over the years stalking you on the internet.

I think I plan on trying heat tape in my next incubator. After reading what you have wrote, I'm suprised that the dead band (overshooting of temperatures) isn't more of a problem with my incubator and 40 watt heat element.

I'm guessing, that because I use a lot of wet vermiculite in the egg containers, and have used multiple egg containers in the past, it dampens the temperature overshoot in the container because of the inherent capacitance, and holds the temperatures more by fluke than by thoughtful design.

Anyone know people who use nightime temperature drops for incubating colubrid eggs? I know a few people doing it successfully for a few years, and they are firm beleivers that their hatch rate percentage has increased for it, and that the babies start feeding earlier since doing so. I don't have the guts to try it, but I won't argue their successes.

Ryan

[Will]

I think I'm gonna use the Heat Tape method, got tons of extra 4" stuff lying around anyways, may as well start using it up.

I have a question about the thermostat -- how do you decide where to attach the thermostat...? Top/bottom/middle...?

[Scales Zoo]

I'm not sure if it would have made much of a difference with my incubator.

I put the wafer thermostat near the middle (from top to bottom), put my thermometer probes in the egg containers, and then calibrated to the temperature I wanted (inside the egg container - before any eggs went in them) by increasing the setting on the thermostat.

Ryan

[Stockwell]

Thanks Ryan...
I guess I have written a book...the pages are just scattered around on various servers and in poor innocent herpers mailboxes(like yours)

[crocdoc]

I had a small fan, almost identical to the one pictured at the top of this thread, running all of the time in my incubator when I first set it up. Because the incubator was very well insulated the heat kept rising well above what I had the thermostat set for. It wasn't until I aimed a temp gun at the fan that I discovered the culprit. The fan itself gave off enough heat to raise the incubator temperature a few degrees C. When I put the fan on the thermostat line (so that it switched on and off) the temperature stabilised.

In my current incubator I am using a dimming thermostat, so the fan has been removed entirely.