Kiln - Making

[Robbo3]

I have a couple of really old magazine articles on how to build your own kiln written by A Jung & Chris Child.

Has anyone made their own?

 

[Woodmonkey]

Thought about getting one of these...

http://www.logosol.co.uk/all-products/sauno-kiln/

 

[Tazmaniandevil]

I've used the airing cupboard in the past, with varying success. Same principal really. Air in & out, mostly constant temperature/humidity. Some woods benefit from being bagged with shavings to help slow down the moisture loss. I found oak, beech, and sycamore dried really well. Yew and cherry dried very quickly and needed shavings to prevent splitting. I know cherry is particularly prone to splitting anyway, so as an experiment put it in a poly bag with shavings. Once a week I emptied the timber & shavings into a dry bag and turned the empty bag inside out to dry. It worked a treat with minimal cracking. I also did a batch of pen blanks using this method.

 

[Random Orbital Bob]

how thick was the cherry, what diameter etc and how long did it take in the airing cupboard using the bag method?

 

[chipmunk]

I know this may be controversial but I've got to ask - what's the rush?

Natural air drying creates the best working timber IMHO - as anyone who's compared it to kiln dried stuff will attest. It's also the most environmentally sustainable way to do it, and the cheapest. It just takes time.

Rough turn by all means or reduce the cross-section but then leave well alone.

Jon

 

[Woodmonkey]

That's fine if it's for turning, but if you are sawing boards from logs, for me anyway, it's a case of storage. If I can use fresh sawn boards within say a month of felling a tree it means I haven't got to store it for 12 months or more in my quite small workshop.

 

[chipmunk]

That kiln's not small though for drying boards of any size, is it? The insulated box to make it anything like efficient is all then dead space in the workshop IMHO that could be used for something else. I actually think it probably only makes sense if you have lots of room.

Jon

 

[Tazmaniandevil]

how thick was the cherry, what diameter etc and how long did it take in the airing cupboard using the bag method?

Cherry was cut & ends painted as soon as it was on the ground. I rough turned cylinders of about 6" long by 4" diameter and packed them away with the shavings in a clear poly bag.
The drying (until the bag stopped gathering condensation) took about 4 months IIRC. Next time I will be better prepared and use scales.
I had no issues with warping or cracking on finished items using this rather crude method.

 

[Random Orbital Bob]

Thanks for that

 

[Woodmonkey]

The insulated box to make it anything like efficient is all then dead space in the workshop IMHO that could be used for something else.

The box can go outside, & they can be disassembled when not in use

 

[Inspector]

There is a little book on making small vacuum kilns suitable for roughed bowls and other pieces wood turners love to play with. I have the first edition and think it has all the information needed to make and use one from locally sourced materials. The book shows the one he uses made from the PVC water / sewer pipes that cities use underground. Large pressure cookers, pots, paint spray vessels etc., would all work too. Makes it possible to dry the bowl blanks in as little a few days. Making one is on my someday to do list. :roll:
http://vacuumkilndrying.com/index.html

Pete

 

[blackrodd]

I have seen several kilns home made from old deep freezers and 1 was a redundant 'fridge unit off a lorry bed!
I think there are still some items on u tube from a while ago.
This is the sort of thing that can quite easily turn timber viewed as firewood, into a really useful source of good stock.
Regards Rodders

 

[Robbo3]

The Chris Child article (The Woodturner Vol 1:4 Dec 97) is partly about re-using an old fridge & I'm sure that I've read another article that explained how to use an old fridge or freezer with a 60w light bulb as the heat source, a small PC case fan for circulation, possibly a fan timer & a hygrometer to record the moisture content.

Youtube has a number of videos about solar driers which I dismissed as being no better than the carport that I'm currently using - well at least my 'chuck it & chance it' method has been 95% succesful.

I was really more interested in the smaller self contained versions with low, or nil, running costs.

 

[Robbo3]

Came across two more articles :
Tony Davis - http://www.woodworkersinstitute.com/page.asp?p=4035
Alan Holtham - http://www.woodworkersinstitute.com/page.asp?p=760

The second one describes using the body from a refrigerated delivery vehicle.

Regards
Robbo

 

[Aden30mm]

I normally air dry, but in winter I use dehumidifier in my conservatory/garage, which works well, and it does speed up the process. However, the temperature needs to be above 5 degrees C for the dehumidifier to work.