Build an Egg Candler

Building this homemade egg candler using a coffee can, light fixture and some rubber will allow you to see inside an egg.

| November/December 1983

To shed some light on the hen fruit fertility question...

"Don't count your chickens before they hatch" is one proverb this poultry raiser has learned to take literally. I know from experience just how frustrating it is to have a hen (or an incubator) waste time trying to hatch an unfertilized egg. However, since I put together my homemade egg candler — a device that allows me to see inside unhatched eggs — not only can I glean the chicks-to-be from the mere omelet fixings, I can also check the freshness and purity of those infertile, "eating-grade" hen fruits. Best of all, my tester was fashioned from a few inexpensive parts and took only minutes to make!

Candler Construction

The main component of my little lantern is a good-sized metal can with a lid (mine happens to be a candy container, but a coffee can or any canister with a tight fitting lid would serve just as well). To make the candler, I first positioned an ordinary light fixture inside the can... punching a few mounting holes in the container's bottom... and then securing the fixture in place with a couple of small nuts and bolts. I made one other opening in the bottom of the canister for the light's electric cord.

On the free end of this wire, I attached an electric plug, and then (for convenience's sake) I added an in-line switch to the cord. To make a "porthole" for illuminating the eggs, I cut a 1 1/2" diameter hole in the container's lid. A 2 1/4" diameter cork gasket glued around that opening prevents any egg from cracking, should it accidentally bump the can while being examined. (If you have a hard time finding such a part, cut your own from gasket material, felt, or rubber.)

I added four legs to the side of my candler to allow for horizontal viewing. These supports were easily made by cutting two 6" long strips from thin sheet metal and then bending each strip to form a pair of legs, which I secured to the can's side with sheet metal screws (you could use pop rivets instead). I also punched a few holes in the container's sides for ventilation before adding a quick coat of high temperature auto engine paint to produce a really snazzy looking finish. Once that had dried, I screwed in a 40-watt light bulb, plugged the contraption in, and darkened the room. With that, I was ready to start candling my eggs!

2/25/2010 1:22:00 PM

I've made simple portable candlers using flashlights. Most of us have one or two around, so the cost of making one is really cheap. The smallest one I've made is a pen light with a short piece of 1/2" pond plastic tubing. This channels the light and works well with small eggs like quail. For a larger version simply purchase table leg covers at the hardware store. The inner diameter must match the outer diameter of the flash light. Next drill a small hole into the center of the cover. 1/4 and 1/2 are desirable. This works well with larger eggs. Hint the brighter the flashlight the better. Simply put your hand over the light and see if it shines through your hand. If it does it will work with large eggs. If it only shines through your thumb use if for small eggs.

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