Small home kiln design

[Jamesc]

Hi all,

This is a post on behalf of my father, he has a rather nice batch of air dried quarter sawn oak that he is looking to kiln dry for furniture projects.

Many moons ago we had an Arrowsmith kiln for when we were restoring a 400 year old farm house. Once the main project was finished and all the floorboards, stairs and paneling kilned he decided to sell it on as he thought that he would only by kilned timber as the need arose.

However this batch of 1 1/2" planks was just too good to miss. The timber is local (Dorset ) estate grown oak, quarter sawn and air dried for 3 years. We test a few pieces and they average at 20%.

He would like to kiln this down to around 8% as this is where all the furniture in the house seems to have settled to.

Does anyone have any simple advice or links for a small (2.5m x 1.5m x 11.5m should do it) and inexpensive kiln. He has two domestic dehumidifiers he can borrow indefinitely and I have plenty of fans I can let him have. ideal we want to construct a temporary kiln as we can't (as yet) foresee a need for it on a regular basis.

Thanks guys

James

 

[woodbloke]

If it's air dried to 20% I wouldn't even dream of artificially drying it further. Keep it outside, well sticked and under cover and then decide what you want to do with it in terms of a project, rough cut it to size and restack it indoors somewhere for a further period of time to condition it a bit more.
The Barnsley 'shop near you keep all their timber in this way...air dried :wink: - Rob

 

[Jamesc]

Thanks for you quick reply.

Being self taught (both of us) we have huge gaps in our knowledge, particularly on the more technical side of things.

Having used the kiln in the past to great success it seemed the way to go. I really must get back and re-read some of my text books as I should really know all this.

It doesn't help that my father is getting impatient to use the wood. He has a degenerative problem that is slowly eroding his ability to use his arms, particularly raising them above shoulder hight. This is time not usage related so he wants to make as much as possible while it is still not too painful to do so. Hence thinking about a kiln.

Regards

James

 

[L Harding]

by the time you go to the expense of building a temporary kiln would it not be easier to just rent time in someone else's? do you have any local saw mills?

 

[woodbloke]

Thanks for you quick reply.

Being self taught (both of us) we have huge gaps in our knowledge, particularly on the more technical side of things.

Having used the kiln in the past to great success it seemed the way to go. I really must get back and re-read some of my text books as I should really know all this.

It doesn't help that my father is getting impatient to use the wood. He has a degenerative problem that is slowly eroding his ability to use his arms, particularly raising them above shoulder hight. This is time not usage related so he wants to make as much as possible while it is still not too painful to do so. Hence thinking about a kiln.

Regards

James

If you decided on a project and roughed out the wood to size, it would take no more that a couple months to condition it to a point where it could be used. I don't personally like kiln dried timber and would prefer air dried. There's always the possibility though that if you kiln it too much you're in danger of 'sucking the life out it' (to quote David Savage)
My advice, fwiw, is to keep it air dried and btw, there is no finer wood to work with (apart from english walnut :wink: ) - Rob

 

[Mr Ed]

I don't particularly subscribe to the view that kiln dried timber is crap, or that it loses its character when kiln dried. I do however, agree that properly air dried timber is probably always going to be better, the question is how often it is properly air dried...

my concern would be that without optimal air drying conditions and set up, the timber is never going to get to the moisture content you want, which in turn will lead to excessive amounts of movement in the finished pieces.

I would personally lean towards finding someone with a kiln to finish the process for you.

Ed

 

[BigShot]

Accepting all the arguments given against making a kiln...
...what if someone wanted to make one anyway?

Let's say they wanted the project, or wanted to dry loads of timber, or didn't have a kiln they could get time in within 100 miles...

...what would they do then given the same parameters in the OP?

 

[SBJ]

This is what I'd do. Well I'd like to anyway. Seems reasonable..then you start looking at their miiling gear....and for a little under 3k you can have a nice little setup...[/dream]

 

[Mr Ed]

Classic Hand Tools sell the Sauno range of kilns

http://www.classichandtools.com/acatalo ... -Kiln.html

Don't know if they're any good but that would be one starting point.

Ed

 

[DaveL]

Classic Hand Tools sell some kiln units which you build a box to hold the timber, I have looked them and it does look like a good usable system.

 

[SBJ]

beat ya!

 

[DaveL]

beat ya!

I never have been fast, but CHT look to be a bit cheaper.

 

[Mr Ed]

Theres a .pdf on the CHT site thats quite interesting, going through the process of building one.

Ed

 

[Chems]

Kiln dried then air dried whilst waiting to be bought it the way to avoid cupping and the other associated issues IMHO.

 

[SBJ]

It was talksed about a bit here

 

[chipchaser]

Hi James,

there is lots of good stuff on the web. I did a quick Google for DIY Kiln Drying.

Some of the authoratitive results include:

http://www.fpl.fs.fed.us/products/publi ... eader_id=p

http://www.woodweb.com/KnowledgeBase/KB ... ation.html

http://www.woodscience.vt.edu/about/ext ... olar_kiln/

I don't somehow think the last (solar kiln) will be much use this year in the UK but there is much good information. Dr Eugene Wengert is, I believe, an expert. If your dad is keen to get on with using the timber you will have to use a kiln and I can't see any problems as long as the drying is not done too rapidly or the wood overheated.

I am sure you can make a useful kiln with your dehumidifiers and fans. I don't know whether it would be fast enough for you without adding a little heat.

Hope you find something of interest amongst that lot.

Regards
Graham

 

[Jamesc]

Thanks guys for your help, advice and recommendations. Some of the links look great.
I appreciate that air drying is the best and that kilns are expensive, its just that we have most of the expensive kit and my dad has limited time whilst he can work so we really want to get the timber ready as soon as possible. He also wants to make sure that his legacy will not be split or bowed furniture.

I plan on taking some photos of his work and posting them here if anyone is interested.

Regards

James

 

[Doug B]

Good luck James, & please do post photos, i`m always keen to learn.

 

[BigShot]

Thanks for responding so well to my nudge, folks.
It looks like quite a bit of useful info has been posted! Good on you all (pats on the back all round and all of that jazz).

James - as to whether we'd be interested in seeing the pictures - I think I can speak for most users of this forum when I say, we insist!
Haha.