I’ve mentioned before that I use a light bulb kiln to cure the oil on my spoons and bowls. My old kiln got kicked around a bit during the move, so I decided to convert my old shop heater cover into a new kiln. You can get really fancy, but anything that holds some heat in will work. So, just a box with a porcelain light bulb fixture and a recycled electric cord and plug.
There are nine recently-finished spoons in there. I still have to take some photos, then I plan on posting them for sale Monday.
I used to use incandescent light bulbs. They are being quickly phased out. But I’ve found these reptile aquarium heating elements to work perfectly. You can find them many places easily, including pet stores. The come in different wattages and screw right into a light socket. My kiln is about 4 cubic feet of space, insulated somewhat. I find that the 75 watt element keeps the kiln at about 130 degrees Fahrenheit. According to what I’ve heard, wood can start to degrade over 140 degrees, so I keep it below that. And that’s plenty hot enough to decrease the curing time by at least 20x (for both linseed and tung oil). Of course, a kiln like this can also be used to dry chair rungs and things like that.
My new kiln doesn’t take up much space. It tucks into the corner of the shop where it does double duty as a stand, typically holding a bowl of dog treats and other stuff.
The doors are secured with a wooden toggle controlled by a simple handle on the outside.
Inside, the toggle is really a semicircle with a bit of a spiral shaved off one side to serve as a cam
When the handle moves up, the cam catches behind the top rail of the cabinet and pulls the door tightly closed. The rabbet holds the narrower door to its left closed.
And, this time, I got really fancy and dropped $25 on a digital temperature controller. These things are made for greenhouses, pets, and all sorts of uses. I plug it into the wall, then plug the kiln element cord into it. If the temperature gets over the max setting, then the power is cut to the element. Once the temperature gets below the minimum setting, the power kicks back on. There’s a cord with a temperature sensor that I’ve run through a little hole into the kiln. On the display above, it shows that the ideal temperature has been set to 130 F (+/- 3 degrees, thus the 133 and 127 numbers). The actual temperature is currently showing 129 F.
As it turns out, the combination of my box and the 75 watt element keeps the box at around 130 anyway, without the controller, but it’s still some peace of mind. With a little experimentation with different heating elements, you can manage the temperature without a control.
Or, this time of year, you can do as I often do and just let oiled bowls and spoons sit in the sun on a hot day. Just be sure to wipe off excess oil from the surface before it cures!
David Fisher, Carving Explorations 