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Help Warping in storage
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Author:  John Hale [ Fri May 30, 2008 4:41 pm ]
Post subject:  Help Warping in storage
This is probably a stupid question from a beginner, but I've recently bought some woods for a top and have been given the wood for the back and sides and they've started to warp now they're in my shop I have no way to control my climate. Currently I've weighted them with books shiming the ends up to reverse to bow. How do you all manage? It must be a common problem.

Thanks

John
Author:  WaddyThomson [ Fri May 30, 2008 4:48 pm ]
Post subject:  Re: Help Warping in storage
You are going to have to come up with some way to control your storage environment, even if you don't control your building environment, and you should control both. Otherwise, you will have to limit certain parts of your build to specific "good humidity" days.
Author:  SteveCourtright [ Fri May 30, 2008 4:51 pm ]
Post subject:  Re: Help Warping in storage
We sticker the wood so that both sides are exposed to air circulation and do our best to keep the RH stable as possible within a range (in the 40s). In my basement shop that means humidifying in the winter, and dehumidifying in the summer.

Others will have to weigh in to help you straighten your wood, which should be possible without too much trouble.
Author:  Michael Dale Payne [ Fri May 30, 2008 4:54 pm ]
Post subject:  Re: Help Warping in storage
Personal opinion you should always sticker your wood for at least a month before working with it if it is at 11percent of so moisture content or sticker it till it reaches about that range if wetter. Even better buy you wood a year in advance and leave it stickered till you are ready to work it.

Depending on where you are and where the wood is coming from there is likely to be a significant difference in RH then add to that the fact that it has traveled through several climatic conditions to get to you of course it want to warp
Author:  Laurent Brondel [ Fri May 30, 2008 6:13 pm ]
Post subject:  Re: Help Warping in storage
What kind of hardwood warped?
If not too thick you could probably carefully flatten the plates with an iron, and a tiny bit of moisture if resilient. Once flat sticker them with rubber bands and some weight.
Depending on how they were cut and seasoned some woods warp no matter what, but humidity control is a must, no doubt…
Author:  Hesh [ Fri May 30, 2008 6:19 pm ]
Post subject:  Re: Help Warping in storage
John buddy what the other guys have said is right-on and there is really no way around the requirement for proper humidity control. Even waiting for those rare favorable days is problematic in as much as the wood does not get time to acclimate properly.

I am having to rebuild a new shop now and although my basement has been hovering around 45% on it's own I plan on wrapping an area in construction plastic so that when it gets more humid the dehumidifier will not have to dehumidify the entire basement.
Author:  John Hale [ Sat May 31, 2008 2:58 am ]
Post subject:  Re: Help Warping in storage
Hi I'm trying to setup a shop in my loft I know, I know not the best of environments, but its there or nothing! The spruce top has warped and twisted slightly and the mahogany I was given was already slightly warped which I'm hoping will come out when I build the sides
Author:  Michael Jin [ Sat May 31, 2008 7:04 am ]
Post subject:  Re: Help Warping in storage
I'm in a similar situation involving my building/storing environment. My wood is suffering from warping. I had hoped to get away without RH control, but frankly given the weather changes around here, I'm finding it very difficult. I think I'm going to have to cave and get myself a humidifier and dehumidifier to control the RH at very least..
Author:  John Hale [ Sat May 31, 2008 7:32 am ]
Post subject:  Re: Help Warping in storage
laurent wrote:
Once flat sticker them with rubber bands and some weight.
Sorry what do you mean by stickering them?
Author:  WaddyThomson [ Sat May 31, 2008 9:54 am ]
Post subject:  Re: Help Warping in storage
Stickered - stacked with equal sized rectangular or square sticks between the boards, and weighted, or not if stable. This allows even air flow around the boards to keep them from warping.
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Author:  Laurent Brondel [ Sat May 31, 2008 11:09 am ]
Post subject:  Re: Help Warping in storage
JJH wrote:
Hi I'm trying to setup a shop in my loft I know, I know not the best of environments, but its there or nothing! The spruce top has warped and twisted slightly and the mahogany I was given was already slightly warped which I'm hoping will come out when I build the sides


A loft you say? You could quickly frame a 8' x 8' room, staple plastic on the frames and makeshift door, and put a dehumidifier in there. Having a window in there is a must to put an AC unit as well, it dries the air the fastest. It also could be a good place to store your parts during the build process.
Author:  Dan Minard [ Sat May 31, 2008 11:56 am ]
Post subject:  Re: Help Warping in storage
Since you live in the southern UK, We are assuming your relative humidity is higher than it should be. It's a good idea to get & hygrometer to monitor the RH.
In the meantime... You can build a box for your tonewood & hang a 60 watt light bulb in it.
You don't need to build it airtight. It wants some movement of air around the stickered wood.
Many of us have tried building our instruments in high humidity conditions. My advice is look after this problem first. It's so disappointing then the back of your guitar collapses or the top cracks wide open, the first time the RH drops down below 30%.
Good luck! Dan
Author:  John Hale [ Sat May 31, 2008 3:47 pm ]
Post subject:  Re: Help Warping in storage
Humidity here is usually around 45% don't know if thats good or bad and temperature range is 18C-28C in all but the coldest winters. I can't go to a lot of expense currently the weighting and letting it aclimateise seems to work well it straigtened and stayed that way for a day now better than before anyway. Mum would go potty about the light bulb thing fire risk and waste of electricity! I'm blessed with what I'm allowed to get away with!
Author:  Sam Price [ Sat May 31, 2008 4:05 pm ]
Post subject:  Re: Help Warping in storage
JJH wrote:
Humidity here is usually around 45% don't know if thats good or bad and temperature range is 18C-28C in all but the coldest winters. I can't go to a lot of expense currently the weighting and letting it aclimateise seems to work well it straigtened and stayed that way for a day now better than before anyway. Mum would go potty about the light bulb thing fire risk and waste of electricity! I'm blessed with what I'm allowed to get away with!


45% is pretty much spot on.

Heh. It often swings from 45% to 65% round my area!! (Welsh Border) Dehumidifying is very expensive becase of rising electricity bills (much more expensive than in the US), I am selective when I switch it on.
Author:  Colin S [ Sat May 31, 2008 4:21 pm ]
Post subject:  Re: Help Warping in storage
John, I live in Kent, and find that the RH is relatively stable for most of the year, never going to the extremes that can be a problem on the other side of the pond. I have never had a climate control system in my shop and have succesfully made more than thirty instruments. I do however have a dehumidifier in the room in the house where I store my wood, this tends to run very irregularly and probably only produces about 5 litres of water a year! My RH tends to stay around 40-50 in the shop, but even if it went outside this range I wouldn't worry too much as the wood is rarely in the workshop long enough to notice. I take the wood from the store, work on it then take it back to the store. But do get yourself a hygrometer (Maplin stock a relatively accurate one for very little) I think you'll find that in London, you'll be OK if you just keep an eye on it.

Colin
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