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Some of my wood has take on a slight curve, the picture is of a set of spruce for a top. Some of my backs have a similar curve.

Is there a remedy to get them straight again ?

John

John, sticker and weight them. Are you control the relative humidity in your shop?

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Aoibeann

Thanks, I have put tape on them.

I moved them for a few hours from about 35% humidity to about 60% as I was preparing a new storage area for them.

John

You need to sticker the wood but that is a case of low humidity. Bring the RH up and that top will flatten out again.

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

If it's quarter sawn wood, the concave side is dryest and that tells you what to do right there.

I've found that wood, when it cups, will ocassionally hold the memory of cupping even when you
restabilise the humidity. When that happen, I will dampen the concave side and wait for it to staighten out.
When it does, you can re-sticker or, even better, clamp thicker material to each side of a stack.

I'll bet that your wood cupped when one side was exposed to air and humidity fluctuations and the other wasn't.
That can happen quite quickly even when the humidity is stable, depending on the moisture content of the wood.

OK this may seem like a daft question but as a new builder can you define the meaning of "sticker" ?

(;-)

John

Hi John, not a daft question at all. You are in luck, this was just discussed the other day here on the forum.

Follow this link. viewtopic.php?f=10101&t=24889

Cheers,

Dave

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Dave

Remember, to always plant trees under which you may never sit.

Thanks, I have an old oak table top that I can rip some 1" * 1" * 20 stickers.

Do you think if I stacked my cupped boards with this method they would eventually straighten out, or will I need to so some remedial work first ?

John

You can draw this cupping out in 24 hours by laying it cup side dowm on a bare concrete floor. Now you must sticker the wood after to give it a chance to aclimate to your shop in the flat condidtion. I never leave plates loose stacked all my wood is sickerd the day it is recived and stays there till I need to work it.

Hi runamuck

The water treatment seems to work, I sprayed a couple of sides today and left them in a room with RH of about 50 - my only problem was I sprayed the wrong side on one of the pieces &^%£(*&^%!

It is currently turned over and very wet on the correct (cupped) side !

John

Whilst on the subject of cupping, storage and RH

I will take you advice and stack my timber as suggested once I have got it flattened out.

I build in my garage which is currently abour 4 degrees and 70% RH, so I store my wood in the house - most of the rooms are a constant 65 - 75 % RH - the only place which I can get near to 40% is in the hot water tank cupboard which varies between 30 - 40% but it is also very warm - sometimes 85f.

I was thinking of moving it to the adjoining cupboard which is a more stable 40% RH - and a more moderate temperature 50 - 60 f

Any suggestions will be appreciated.

John

Ideally you want to store and work in a constant temp and RH. If the wood is seeing regular swing of 10% or more it really never stabilizes. Slow changes are not bad but quick and frequent changes makes wood dance better than the pros on “Dancing with the Stars”.

If like me where you build in a shop where the mean averages between 30%-38%Rh at 70F-80F then you want to store in that same condition, I only have to control the temp for the most part. But if your work shop sees frequent and rapid changes in either temp or RH then you want to think about creating a controlled environment for storage.

When stacking using stickers what is the rule of thumb for the maximum number of boards stacked ?

Jc

Is the a minimum size for the stickers at the moment I'm using 3/16" mdf, with sets back to back with a sticker between sets.

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Formerly JJH

I learn more from my mistakes than my successes