Moisture

[Anonymous]

Hi
I thicknessed some pine to size a couple of days ago and when I came to use it I found that it has now cupped and one board has twisted. We recently moved house and the new garage is heated and warm whilst the old one had no heating. Could the problem be simply that the wood dried out? I have owned it for about a year and it sat in new garage for 1 month before thicknessing without any cupping or twisting until after it was machined!!

This has raised the question (again) is it worth investing in a cheap moisture content meter?

Thanks for any help

 

[Drew]

Hi Tony

is it possible that you thicknessed it on one side only. That could leave an imbalance leading to cupping.

just my tuppence worth, probably going to get shot down.

Drew

 

[Alf]

Sounds plausible to me, Drew. Tony, it could be in preparing the timber you released some built up stresses. Or merely it's the usual 7 parts knots, 9 parts water "pine" which will bend like a banana at the drop of a hat and, as you say, it simply dried out. I don't have a moisture meter myself, so I do a few things to try and minimise this. Firstly with pine especially it pays to let it acclimatise to where ever it's going to end up for as long as possible (with some of the stuff I see you're probably talking months ), stickered to allow the maximum air flow. Then, when I come to machine it I try to take off some from both sides, as Drew suggests, and not get to the finished dimensions in one go. I get close then return it back to it's stickers in whatever nice warm place it was in before for "a while". With my strike rate this can be months , but you might get away with as little as a week. Then machine it to the final size and go from there. But don't make the mistake of leaving your timber in the workshop if it's not as nice and dry as the place it was stickered in, or all your hard work will come to nothing. Between working on the wood I tend to sticker it again, and often stick some weights on it too, just to give it the hint that I don't want it cupping. It's a total pain having to carry timber between the house and w'shop or whatever, but it does work. Hope there isn't too much egg sucking instruction in there, but even so it might be of use to someone else I s'pose. :?

As to buying a moisture meter; well if it was the stresses in the timber rather than the moisture, you'd be no better off. It's one of those things that'd be nice to have, but whether it's worth it depends on the wood you're buying, where from etc I think. If you were buying air dried, for instance... :wink:

Cheers, Alf

 

[Anonymous]

Hi

My workshop/garage gets quite damp @ times, as the rust does show its face on vunerable surfaces quite quickly.

I've been considering a external de-humidifier.

Anyone else been this route?

 

[Anonymous]

Thanks for the advice guys. I took it down from 22mm to 15mm on one side only......

 

[johnelliott]

One thing that puzzles me, why is pine being thicknessed, or worked on in any way? Pine is the 'Happy Shopper equivalent of proper (hard)wood. If you've got a planer thicknesses then you should be buying and using hardwood. Get some kiln-dried timber from a reputable supplier and make something worthwhile with it. There is no point in wasting your valuable woodworking time on material that simply isn't worth it, will twist and cup, is as soft as s**t and is quite likely to clog your equipment and your sandpaper with its nasty soft fibres and resin.
If you check the prices carefully, you will find that it's not that much cheaper than proper wood either
John

 

[Anonymous]

John

I usually use Ash or Oak but the pine was less than half the price and is from a good merchant (not B&Q) - quite hard for pine. I quite like pine as well - not to work but to look at.