In Shop Blog

We may receive a commission when you use our affiliate links. However, this does not impact our recommendations.

I was surprised by how much my CompWood arm
bow dried out overnight. It went from 20 percent moisture content to 12
percent moisture content. But I’m not ready to take it out of the
clamps yet, and Megan wouldn’t do it, either (she smelled a
trap/workers’ comp claim).

So I decided to do what I’ve done with
steam-bent arm bows: Put them in a homemade kiln. I first learned this
old trick from bodger Don Weber. Build a cardboard box and put it a
lightbulb in it. Then make some “Dukes of Hazzard” noises – “coo-coo!”
And wait.

I dug up two used boxes from the mailroom, swiped a
desk lamp from the cube of a co-worker who had been let go and had the
whole thing up and running in 15 minutes.

The contraption raises the ambient temperature by 10° Fahrenheit. I’m not sure how much that will help, but it sure can’t hurt.

— Christopher Schwarz


Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.

Recommended Posts
Showing 18 comments
  • DENIS

    I MADE A SMALL KILN, BOUT 16" X 16" X 10′,OUT OF PLY AND VINYL SHEET. HAS A SMALL CERAMIC HEATER AND A "IN THE DUCT FAN" HAS HOLES IN THE TOP AND BOTTOM FOR VENTILATION. WILL DRY BOUT 60 BD FT IN ABOUT 30 DAYS.
    OPERATING COST IS BOUT $ 1.00 A DAY. $ 0.88 PER BD FT DRY AINT TOO SHABBY. IF INTERESTED I COULD SEND PIC OR DWG.

  • Mike Sarver

    Chris,

    I work in a steel tank manufacturing facility, we use an old refrigerator to dry our flux in. Basically take an old refrigerator, take out all of the shelves, drill a hole through the side to run a wire thru for an 100 watt light bulb. Plug it in, turn on the light, close the door and instant kiln.

  • I live in Arkansas and if that really was an Arkansas Insty Kiln you would have used a Tyson Chicken box or better yet a Walmart box :0 )

  • Tom Bier

    You might think this trick will be short-lived with the upcoming phase-out of incandescent bulbs, but I just heard a story about ‘heat balls’. There’s a German businessman selling these little spherical heaters – they just happen to screw into a light socket and incidentally give off some visible light along with the heat!

  • Mike

    OSHA is a broom and dust pan 😉

  • Don’t use the pretzel light. If it breaks you need to call OSHA to clean up due to mercury in the light.

  • R francis
  • Christopher Schwarz

    Steve,

    A lightbulb inside a large cardboard box – not touching the cardboard box — causing a fire is far-fetched.

  • Steve

    It is fitting that you ended your article on how to start a fire using a lamp and cardboard box with the famous last words "it sure can’t hurt."

    Hope I am wrong.

    Steve

  • sqrft.blogspot.com

    The light bulb will work quite well, especially if it is around 100W. If I remember correctly, 90% of what a light bulb produces with it’s 100W is heat, only 10% goes into producing light. Want proof? Look in your daughter’s Easy Bake oven. Same thing for dehydrating foods (hmmmm, home-made jerky…. hmmmmm) a box, a light bulb, and a computer fan hooked up to a D cell battery like was previously mentioned. The fan will spin just fast enough to remove the moisture without sucking out too much of the heat as well. As well, instead of just using the blue foam, look for the foam that has been covered in aluminium foil. Holds heat something fierce, hence the need for the fan.

  • Derek L

    Agreed on the fan, you need a way for the air to circulate and a way for at least some of the warm and now moist air to escape. A closed environment is a stable environment, not a drying environment.

  • Bill

    You should have a PC around that you are not using. Pull one of the fans and a D volt battery. I know it supposed to be 12v but it should spin enough for what you need. Cut a hole in the top side panel and lay the battery on the top it will last as long as you need it too.

  • Don Williams

    I always collect the fans when a compewder goes to the great scrap yard in the sky. They are great for little projects like this when you need only a little air moving around to carry off moisture.

    I also use little computer fans or squirrel cage fans to construct activated charcoal air scrubbing filters. the computer fans are almost exactly the same size as a case of .223 ammunition, so voila you have a ready made tiny box fan with a chamber for activate charcoal. Keeps the basement shop from stinking up the house in the winter.

    Great info AL. will store that one away in the cerebral archive.

  • Doug F.

    Instead of cardboard try some of that blue foam insulation that they use around concrete when building houses.It’s cheap, holds in a lot more heat, and is just as easy to work with.

    I agree on the fan, also.

  • Steve

    Ditto on the fan. In fact, I think the fan is really all you need this time of year, when indoor humidity levels are pretty low.

  • Charles Davis

    Pretty cool idea. Reminds me of back in elementary school when we cooked hot dogs in tin foil lined shoe boxes set out in the sun. This is just like that without using a shoe box, the sun, and hotdogs… well, I’m sure you could bend a hot dog in your kiln jig if you wanted.

    Geez, Megan is really getting wise to your traps anymore. I’d suggest slathering peanut butter all over the arm bows. This always works for me in fooling local squirrels into traps… even the really smart ones.

  • Don

    It’s also helpful to have some ventilation holes in the top of the box. Warm air will escape, but it will take moisture with it.

  • Al Navas

    Chris,

    I believe it will work, if you give it a little time. Also, use a small fan, to make sure you have some air circulation.

    Background: My brother-in-law harvested some trees on the family farm just South of where we live. Took the boards to a saw mill, then drove home with the load. He stickered the stash in the garage, and spread a tarp over it. He dug up an old fan, and aimed it at one end of the stash. A month later, moisture was down to 12% (if I remember correctly). The garage was warm, so the entire arrangement behaved like a solar kiln.

    In your case, using too strong a fan might defeat the purpose of the light bulb, depending on the temperature in the room/shop. But it’s worth trying it.

    This all happened in late Winter, as he harvests trees only during the Winter months, "when the sap is down". The temperature in the garage did not reach that which a solar kiln normally will, but still the boards dried nicely.

Start typing and press Enter to search