# Keeping kiln dried timber dry



## Benpointer (18 Oct 2022)

Hi all, I have some lovely kiln-dried quarter sawn oak which I plan to make a sideboard from. It was sold to me as dried to 12-13% which seems to be true although I have yet to cut any in the middle and check there... but I trust the supplier. 

The boards have been stacked in my lounge for six weeks (against Mrs P's wishes), so I am confident it will be pretty stable. 

My question is when I take it to my fairly dry but unheated workshop next week for cutting, planing, jointing & finishing do I need to do anything to protect it from gaining moisture again? If so, what should I do?

I am a slow worker so I think it could take me two months or more to build the sideboard and it's just not going to be practical to keep taking the timber back and forth.

I'd be grateful for any thoughts or suggestions.

Thanks


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## Bingy man (18 Oct 2022)

In my limited experience with storing timber I’d say to leave it it your workshop to acclimatise to the temperature within. Stack it with air gaps all round and maybe rotate the stack from time to time Others with more experience will hopefully be along to advise you further .


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## rogxwhit (18 Oct 2022)

There are so many imponderables here (= missing information) that my counsel would be to just relax about it and proceed at your own pace.

I'm curious as to whether the boards were separated or stacked in contact whilst they were in your lounge?


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## Yojevol (18 Oct 2022)

12% doesn't sound like very kiln dried to me. I would expect something more in the region of 8%. 14% can be achieved with air drying alone. If it is as you say then it's not going to alter much in your workshop. 
I would take a small sample and put it on a c/h rad to accelerate the drying out process. Measure the m/c daily until it reaches equilibrium. You'll then have a better idea of the m/c of the stock. 
If the timber has been properly air then kiln dried there won't be any noticeable difference between interior and surface.
I wouldn't worry about trying to control the m/c. You're sideboard design should have the usual features built in to accomodate movement and, if in the fullness of time, it does dry out some more, it should be of little consequence. 
Brian


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## rogxwhit (18 Oct 2022)

Yojevol said:


> 12% doesn't sound like very kiln dried to me. I would expect something more in the region of 8%.


Kilning in itself doesn't betoken any particular moisture content, which is up to the operator. It's just a method of accelerating the drying process compared to air drying. And your notion of 8% sounds a pretty fierce target.


Yojevol said:


> If the timber has been properly air then kiln dried


People often rush things, the motive being money ...


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## niall Y (18 Oct 2022)

We are going into winter now, so depending on the insulation and heat in your workshop, it's going to be colder and damper in there. Despite having a fully insulated workshop, I try and limit the making of large ,cumbersome items of furniture to the summer months, so the temperature and moisture difference between workshop and indoors isn't too great. If the pieces are easy to move then you can ferry them back and forth, so no problem on that front. 

A clear indication of dampness in my workshop is that any sheet of paper I take out there always looses its crispness and softens up. Unless one can match the conditions in ones workshop to those indoors, there is always going to be that nagging doubt that the piece of furniture will react badly once brought inside.

Not sure you really want to here this, but it might be wiser to delay. Not sure how your partner will react to this news. I once had a whole pack of oak floorboards acclimatising in the main bedroom at home. It was meant to be for a few weeks- though it went on for a few months. And , yes we are still together.


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## Benpointer (18 Oct 2022)

Thanks (I think!) for the advice so far. 

I am definitely going to design to accommodate movement but I will also try some of the other suggestions too, except delay - Mrs P. tells me that's not an option  

Thanks all!


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## Sgian Dubh (18 Oct 2022)

The commercial kiln drying target for North American furniture grade wood is 7% MC ±1%.
Similarly, the target for commercial European kiln operators for furniture destined wood is 12% MC ±3%.
Air drying alone here in the UK is extremely unlikely to bring wood down to 14% MC. The most likely low MC purely air dried wood will reach in the UK is in the region of 18% MC, and that's really only the south east of England, e.g., Essex and Kent. 

What happens to the wood's MC after it's left the kiln is down to how it's dealt with, e.g., stacked, banded, wrapped, transported, storage conditions, and so on. Slainte.


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## Adam W. (19 Oct 2022)

Benpointer said:


> Thanks (I think!) for the advice so far.
> 
> I am definitely going to design to accommodate movement but I will also try some of the other suggestions too, except delay - Mrs P. tells me that's not an option
> 
> Thanks all!


Stack it in the loft.


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## Yojevol (19 Oct 2022)

Benpointer said:


> Thanks (I think!) for the advice so far.
> 
> I am definitely going to design to accommodate movement but I will also try some of the other suggestions too, except delay - Mrs P. tells me that's not an option
> 
> Thanks all!


One suggestion to make some progress and help with the storage problem - ASAP saw all the component parts with a generous planing allowance. Stack it for a while to allow any consequential movement to come out. Then proceed with planing in 2 stages with a rest period between each.
Brian


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## somean49 (20 Oct 2022)

if you stack it in the loft the house might tip over


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## dzj (20 Oct 2022)

November and December are months with the highest natural EMC. If this is when you're going to make your sideboard,
keep the door and drawer gaps as tight as possible. 
I would suggest that you rip your stock 5, maybe 10mm wider than final dimensions (depending on length) and then
bring it inside for a week or 2. It will lose some moisture and it will show bowing and twisting
if there are any internal stresses.


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## CStanford (20 Oct 2022)

If your home workshop has no HVAC, then keep the project stock in the house and move it in and out of the shop and house as you work on it. There's really not a lot else you can do. It's a hassle.

Whether or not the supplier/sawmill, etc. have done a proper job drying it is another matter altogether. You have to buy wood from somebody you trust. Once it's in your hands, it's up to you to acclimate it to its permanent home as best you can. Unless the project will be of very short duration, you really can't leave it in a damp shop and not expect something bad to happen.

The other alternative - leaving it in the shop to come up to its climate and moisture level, and then guessing about how much it might move when the completed piece is moved into your home, is playing roulette. If you're working an endless supply of Cuban mahogany it might work, but otherwise, no.


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## Benpointer (5 Nov 2022)

Thanks for all the suggestions. 

I have set up a background heater and a de-humidifier in the 'inner sanctum' of my workshop - a separate insulated room where I keep all my tools. I have stacked and sticked all the timber on a trolley made of two dollies joined by a couple of length of straight dry 4x2 and wheeled it into the inner sanctum. It just about fits in. I have to wheel the stack out into the working part of the workshop each time I do some work on it and back again at the end of the day.

I will report back if this proves to be successful or not (!)


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## Reffc (6 Nov 2022)

Short of keeping a dehumidifier going and stacking cut timber with plenty of air gaps, there's nothing much you can do to prevent it gaining MC %.

I have, for a long time, stored my ply sheets indoors much against Mrs R's wishes and taken them out for cutting and jointing in the workshop for the speakers I make. Each pair of large ones can take a month as they're a very complex build, internally and externally. Invariably once they're completed and back inside a nice dust free environment for finishing, then left a few weeks to a month whilst I build up the oil and wax final finish, any junction of hardwood or ply end grain to ply which was planed and sanded flat in the workshop develops a step as the ply tops shrinks back on the layers, creating a miniscule step in the veneer above. You can just about see it on the veneer and you can definitely feel it but short of mitre join everything it's a fact of life when joining dissimilar timbers and laminates this way as once inside, you'll get dissimilar shrinkage at such junctions. I think 8% is very optimistic personally, as the final piece will inevitably take on whatever MC it's final location will be. With energy prices being what they are, heating a workshop and running a dehumidifier is a non starter for me as things are expensive enough as it is, so the best I can do is store materials for my next job indoors somewhere for at least a month or two.


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## hugov (29 Nov 2022)

I've been very happy with what a small zeolite-based electric dehumidifier (EcoAir DD1) has been able to accomplish in my workshop. Admittedly the workshop is a garage attached to the house, so doesn't get as cold or damp as a shed or something would.


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