Picture of Styrofoam Forced Air Egg Incubator v 2.0
In order to hatch fertile chicken, duck, turkey or other domestic poultry eggs, you need a broody mother bird, or an incubator. If you have the money for it, you can buy extremely functional styrofoam incubators for just over $100 (and smaller, 3-4 egg "classroom" dome models for less yet). And of course you can always pay a lot, lot more. But if you don't want to spend that kind of money, it is still possible to put together a functional "forced air" box incubator at home for just a few dollars, using items you may have around the house or can buy readily at any grocery, thrift, or drugstore (except for the thermostat, which you'll find at Home Depot or other hardware store.)

My total cost for the incubator in this Instructable was about $30. Your cost may be less if you can salvage or re-purpose parts you already have around the house.

Estimated assembly time once you have all the bits together: about 2 hours

You will need:

Serrated knife or hacksaw blade
Duct tape
Electrical tape
Tin snips
Leather gloves
Wire cutters
Wire stripper
Sharpie pen or other marker (to mark on the wire and cooler, not the eggs)
Vacuum cleaner
Pencil (to mark the eggs if desired)

1 styrofoam ice chest, the thicker-walled the better (I got my Omaha Steak shipping box free by asking on Craigslist.)
1 bottle lamp assembly (Home Depot, about $10 - I salvaged mine from a lamp from a thrift store for $6)
1 lower-element, single pole water heater thermostat ($7.57 at Home Depot)
1 25 W bulb
1 12 Volt transformer (from any defunct electronic device)
1 PC Core fan (scavenged or a dollar or two - I got mine from PC Recycle for $2)
1 plastic (preferred) or glass from an inexpensive picture frame ( I salvaged mine for $1 at a thrift)
1 shallow dish for humidity
Wire hardware cloth (about $9/roll if you don't have leftovers from another project)
Aluminum foil

1 indoor/outdoor probe type thermometer/hygrometer, about $12 at Home Depot or Walmart
1/2 C salt
1/4 C water
Large zip-close plastic bag

For candling: 1 Mag-Lite flashlight or other similar extremely bright light
A source of freshly laid, fertilized eggs (NEVER refrigerated)

To increase humidity rapidly: a spray bottle of water

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admin5 years ago
This is a great Instructable, but you need to add a main image of the final project to the intro step. Please do that and leave me a message when you have so that we can publish your work. Thanks!
chotii (author)  admin5 years ago
(removed by author or community request)
dr909 chotii5 years ago
I homeschool, and my 8-year old wants to incubate an egg for a science project. Your incubator looks like it is simple to build and inexpensive. At the time of publication, though, you had not yet completed the incubation cycle for your own eggs. I am wondering how it worked out. Did you successfully hatch any chicks?Thanks!
chotii (author)  dr9095 years ago
Hi there, I had 6 out of of 15 eggs hatch yesterday and today in this incubator. 2 more may yet hatch. These were 'shipped' eggs bought online, so a 50% hatch rate is average, and I'm pleased! I can tell you now, this design works very well. It really, really needs to be in as cool a location as possible. It's excellent at keeping itself warm; it has a hard time cooling itself off. We're having a heat wave (it was 104F yesterday in late afternoon, and about 90F in my garage) and this incubator occasionally crept up to 102F inside despite sitting on the concrete floor AND having a fan blowing across its surface. The eggs hatched (which just goes to show you they're resilient little creatures) but I've had to really keep an eye on it.
chotii (author)  dr9095 years ago
Hi there, you might want to look at this instructable again - I have completely revamped the incubator instructable, with much better pictures and (now) a proven record of a successful hatch inside it. It does make quite a large incubator, so you know in case your space is limited.
chotii (author)  dr9095 years ago
I got a duck egg to 21 out of 28 days, and then transferred it to a larger incubator with a built-in thermostat (using this set of instructions: ) and the duckling did hatch and was fine. I can't know whether it would have survived in the smaller one.

I will be making a new instructable describing the process of building the bigger-better one (although there are plenty of great instructions over at BYC. Here is the one I like best: but you really need the wiring diagram on the first link above, if you're anything like me. :D
david319q1 year ago
Would you suggest using a dimmer switch
B371 year ago
I don’t know if this is still an active article or not, but will try. --- A lot of very good information. I am wondering, if when calibrating a hydrometer using the method of a saturated salt/water solution, how accurate will this be at various temperatures, especially around 100 degrees F. TNX
chotii (author)  B371 year ago
The honest answer is, I don't know. I now use an electronic hygrometer/thermometer (like Oregon Scientific) - the kind you'd use inside your own house. I try to incubate around 30-35% humidity until the last 3 days, when I bump it up to about 70%. I get very good hatches from local eggs that have not been shipped. My suspicion is that as long as you're in the ballpark, healthy eggs will hatch. There must be a great deal of variation in nature, after all - temperature and humidity both.
Would it matter if you put the lamp and fan on the lid vs the side?
chotii (author)  CC Switchblade3 years ago
I think the important thing is to have the light bulb not touch the window, the walls, or the lid. The higher the bulb, the more the air will have to be forced back down to where the eggs are. Whatever else you do, make sure the temperature is stabilized at as close to 99.5 for at least a day inside your 'water wiggler' on top of an egg carton or however you choose to incubate the eggs *before* you put any eggs in. The temperature near the lid will always be higher as the heat rises significantly.

I have never tried putting the bulb on the lid.I can't think of a good reason not to.
amioten3 years ago
I like this instructable because since i made one of these i made over 40 chickens and still hatching ducks!!!!!
dbriggs13473 years ago
What did the internal temperature of the water wriggler range from?
chotii (author)  dbriggs13473 years ago
I have seen the internal temperature of the wiggler range between 97F and 102F without harm to the chicks. I aim for as close to 99.5F as possible. Put the wiggler at the same level as the eggs (I have even laid it on top of the eggs). If you lay the wiggler on the floor of the incubator, but use the egg-carton method of incubation, so some eggs are tilted up and some down, you'll find that the temperature in the wiggler registers as much as 2 degrees less than the eggs are getting a few inches higher. It's really amazing how much of a difference a couple of inches make, even with the fan blowing in the incubator. I have toyed with the idea of trying to make the fan blow down at an angle but have not accomplished it yet. Anyway, if the wiggler is at the same level as the eggs, it will record the correct internal temperature for the eggs at that elevation in the incubator.
I know what your saying. What I actually did was raise the platform for the eggs up a couple inches and lowered the fan to match the height of the platform. By doing this I also increased space for more eggs. It was a double win.
qclark3 years ago
Hi, I've been working on my incubator for a couple of days now and am having a problem with the temperature fluctuating from as low as 93.3 clear up to 103.3, bad thermostat? (i'v tried placing it behind and infront of the aluminum and still have problems)
chotii (author)  qclark3 years ago
Which kind of thermostat are you using, the 'lower thermostat' for a water heater, or a disc thermostat designed for incubators? I eventually gave up on the water heater thermostat because of similar temperature swings and wired in a disc thermostat:

I find as long as the thermostat INSIDE THE WIGGLER stays between 98F and 102F (but ideally as close to 99 as possible - I mean, brief spikes to 102 have NOT killed my whole hatch), it's okay. I've hatched 6 or 8 broods out now using the same incubator but with the disc thermostat.

The more water mass you have inside the incubator, be it the water tray underneath for humidity, a couple of small bottles of drinking water, or a larger quantity of eggs, the more stable the temperatures are going to be. I've been experiencing problems with the end of hatch, as I take chicks out and the reduction in mass inside the incubator seems to confuse things. I have now 3 different indoor-outdoor thermostats with probes inside the single wiggler. They each register slightly different temps, and I average the 3.

However, a 10 degree fluctuation definitely needs adjustment and possibly a better thermostat.
You've only done one duck? Wouldn't it make sense to hatch as many as you can even if you just sell them? I'm definitely going to make one of these. I and a neighbor have been discussing buying one to share but this would be so much more convenient and cost effective. Thankyou very much!
BoogieWipes4 years ago
Hi there I have 1 rooster and 11 hens and there all laying and i'm eating them and I had an idea and I was thinking breed for money. Awesome
michael39664 years ago
on the wire floor add 4 inches to the width and length after your measurements, that will add the 2 inch fold .
undrline4 years ago
Doesn't the humidity cause problems with the electrical items (fan/light fixture/etc)?
chotii (author)  undrline4 years ago
I can only tell you that I have never yet run into humidity problems. But most of the time the humidity is 50-60%. It only gets a little higher during hatching. I imagine that the humidity is higher in many parts of the United States all summer long, and I have never heard of problems with electrical fixtures there either.

You're more likely to run into humidity problems in the eggs themselves - too much humidity through the incubation process, and the chicks won't hatch properly. Or they may drown when they pip internally (break into the air cell, which by hatching should take up at least 1/4 of the volume of the egg). If the humidity in the incubator is too high, the moisture in the egg won't evaporate adequately, and the air cell won't be large enough. The chick will drown when it tries to breathe.

pitajames4 years ago
Fantastic instructable. One of the best I've ever read. Well done.
chotii (author)  pitajames4 years ago
Thank you. I just finished hatching out my second batch of the year in this incubator and am picking up eggs from a friend to start another. I need to make a change to it though: I have given up on the water-heater thermostat and now am using the GQF wafer thermostat for the Hovabator incubator: It holds a far steadier temperature with less fussing. I wish I'd just splurged for it before.
 What's up with the bag around the temp probe? Maybe I missed it but I couldn't figure it out.
chotii (author)  josephcrawley5 years ago
Hi, that's actually a "water wiggler" toy, meant to simulate an egg. The probe goes into the wiggler; the water in the wiggler reaches and sustains the desired temperature; then you know the content of your eggs will also reach and sustain the desired temprature.  You can also purchase "eggs" on Ebay that will perform the same task. People have done all sorts of creative things, like blow the contents out of a real egg, fill it with dishwashing liquid, seal the ends with the temperature probe inside, and put that into their incubator....

I found that water wiggler toy at a local specialty toy store, but they can be purchased in many places, such as local WalMarts.
halolord5 years ago
You should an egg carton to hold your eggs in, so that they are staying straight and not harming your specimen.
leaving it straight up the whole time WILL HARM IT.

u have to turn the eggs a few times a day at least

chotii (author)  Mr. Smart Kid5 years ago
However! You can put the eggs in an egg carton, small end down, and put a block of styrofoam or what-have-you under one row of eggs (that is, along one long side), and then under the other, at least twice a day. This accomplishes the same thing as 'turning them', and  there is no chance you might accidentally drop an egg (as does happen sometimes when you turn by hand). Also, moving the blocks can be done quickly with little heat loss to the incubator, versus the time needed to turn each individual egg.

I have successfully hatched eggs using this method of tilting the eggs from side to side.
I've spent ages recently looking at creating an incubator, your's is a good example and I'm sure works well. I'm now somewhat obsessed.
I've decided to over-engineer mine as much as possible with automatic thermostat control, fans etc. I work from 6am until 7pm away from home, so want to automate as much of the process as possible. I also want to make it large enough to use as a small brooder as the controlled temperature and seem a good idea.
I'm also going to try and build an automatic egg turner, which is where I'm struggling. I think some Arduino experts may be able to help. Have you any thoughts on automatic turners and how to go about it? They'd make a great addition to any DIY Bator.
chotii (author)  Nemesis2010775 years ago
I'm afraid I don't know anything about making an auto-turner, but they've been discussed (right down to gear ratios et al) on in the 'incubating and hatching eggs' forum. With my own eggs, I just turned them by hand morning and evening, and got a 50% hatch rate from shipped eggs (which is average, regardless of what incubator/turning method you use).

Good luck!
I did look on but they all seem to be talking about much larger systems.
I have come up with a cunning plan however, which involves a servo motor with a simple controller that tells it to tilt one way, wait 4 hours, then tilt the other way.
Now all I need to do is learn electronics, soldering, PIC programming and fabrication of the egg turner. EASY!
Thank you so much for this instuctable! I am so glad that i found this site.
I have been looking for a 'how to' on making a cheap incubator, and this is just perfect! I think i am going to make this (i just have to ask my dad, but i think he will say yes). Thank you for putting pictures up with your step by step instuctions, if you didnt then i would be very lost.
Beautiful job, keep up the good work!
chotii (author)  shelly1239875 years ago
You're very welcome. the first one I made, working from less detailed instructions / zero pictures, took me HOURS. I hope this will only take you a couple of hours, and not cost much.