kiln drying question

[Lee Alkureishi]

Hi all,

A potentially dumb question, but bear with me! let me preface this by saying that I know very little about kilns and kiln drying.

That being said: my wife is just getting into pottery as a hobby, and I've stumbled upon an electric kiln for a great price. After some very preliminary googling, it looks like wood drying kilns operate at a much lower temp than pottery kilns (120-190F vs 2-3000F).

Is there any way to safely run an electric kiln at the low temps required for drying the odd bowl or 2? Or is this craziness?

Thanks,

Lee

[Roger Chandler]

I have little knowledge here, but I have an aunt that has done pottery for years and has two kilns. They use them to fire the ceramics and glazes that make the hardened outside shiny and durable. These kilns are very hot.........hot enough to burn wood. I am not sure that they will got down to the temp to dry wood..........

I believe this to be the facts, but again I do not have personal knowledge here........only what I have seen and know that the kilns for ceramics have fire brick linings in them and that indicates to me that there are way too high temps in the thing for wood.

Maybe someone else can give you more definitive answers, Lee.

[Bernie Weishapl]

I think that the heat from a creamic kiln would be way to hot to dry wood. My frig design uses two 40 watt bulbs.

[Richard Coers]

You can't start drying wood much above 90 degrees, especially thick stock. The highest they ever get is 135-140 and that is when it's finished drying and at that temp, bugs and bug eggs are killed. They also take pine to that temp to set the pitch. Also kiln drying is not all about heat. It's air flow, measured moisture loss, and time. If you are drying pre turned bowls, it's a little different, but with those, you start at room temp if the wood is questionable for cracking. As Bernie said, a couple light bulbs give you plenty of heat.

[Lee Alkureishi]

Thanks for the advice - was thinking that was the case, but never hurts to check!

[Darius Ferlas]

No need for any source of heat other than the Sun, and even that can be a tad too hot at times.
I built a small solar kiln a few years ago. I can put up to 400bf in it and depending on the species, weather etc, it takes 2 to 3 months from green to 10% MC

[Thom Sturgill]

What I've seen done and called a 'bowl kiln' is to gut an old refrigerator and put vents top and bottom. rig a small fan at the top to extract moist air and make a light mounted in the bottom turn on if the temp drops below some pre-set value. Seen the same done in a closet.

David Ellison claims that it is air flow that causes cracking and says just put the bowl where the air flow can be minimized (like in a bag, or pile of shavings). When I built my shop, I built cabinets along one wall with deep full extension drawers. I use some of these to dry bowls. While I have not done that many yet, success has been good.

I have a pottery kiln and it uses a heating strip similar to a toaster. I seriously doubt that you could regulate it down to a suitable temp.

[Jerry Marcantel]

As a Flintknapper, I can say without a doubt that you can convert electric kilns to produce low temperatures. When cooking rock, we need to keep the first 24-36 hours under 200 degrees to evaporate moisture in the rock. If you go over 212 degrees right away, the rock builds up steam causing it to explode, crack or potlid. Someone came up with the kiln conversion for low temps. Cooking the rock changes the workability of the stone and in some cases, will change the color..
My kilns after being converted now can maintain as low as 100 degrees for weeks if I wanted them to. The drawback to making this change is your kiln will now only create temps from under a 100 to 700 degrees or less. That's done by changing the coils and switch in the kiln. When making the coil, it l should read 17 ohms, using about 80 feet of stainless welding wire at .035". The switch part number can be gotten to you if you really go that route.
If you plan on doing pottery, save the old switch/coils and put them back in for higher temps............. Jerry (in Tucson)

[Lee Alkureishi]

Jerry, thanks for that info - that's pretty awesome :) I'm not sure I'll go down that route, though - it seems like it wouldn't lend itself to easily switching back and forth between wood and pottery temps, and I can just hear the wife now... "you did WHAT to my new kiln???" :P

Thanks to all for the other info on wood drying kilns - it'll happen at some point!

Best,

Lee