# Dealing with wood warp in a finished project



## 0331reaperguns (Mar 13, 2019)

Hello all!

Newbie here. Just got my shop put together/finished last year but have been working for a little over two years. Still very amateur. 

I made this pipe box for my brother in law last summer and really felt great about how it turned out. It is made from red oak and was finished with an oil based stain. There are plenty of goofs and things I would do differently, but for my first pass I was proud to give it to him as a birthday gift. Note that everything was very square and seemed to work beautifully. 
https://www.woodworkingtalk.com/attachment.php?attachmentid=372967&thumb=1
https://www.woodworkingtalk.com/attachment.php?attachmentid=372965&thumb=1

I visited in December to find that the top and bottom of the box had bowed inward and caused the box to be unusable. I was embarrassed and felt horrible, vowing to immediately find a way to fix it or build him a new one. This is obviously the result of extreme environment changes. I do my best to keep my shop climate controlled, but I'm in Missouri and my shop isn't exactly state of the art. The humidity swings are significant from winter to summer. 

https://www.woodworkingtalk.com/attachment.php?attachmentid=372971&thumb=1

Can anyone please provide feedback/input on how I might be able to correct this piece? As the humidity has started to pick up in the month of March, it has already started to correct, so I suspect if I let it rehydrate a bit, I might be able to seal it and keep this from happening again. Is this a reasonable approach? Are there sealants that will prevent this from happening? He wants me to try to fix this one as much as possible, as he said it has sentimental value and he is proud to have one of my first pieces. 

Thanks in advance, I sincerely appreciate the experience and input from the community!

S/F

Matt


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## difalkner (Nov 27, 2011)

Welcome to the forum, Matt! When you get a minute add your location to your profile so it shows in the side panel. You can add your name to your signature line and it will show in each post.

Is there an actual finish on it or is it just stained? If it has a finish, did you finish both the outside and inside? Wood moves as it takes on and releases moisture and if the finish is only on the outside then the pieces are going to move more, usually cupping toward the finish side. Was the wood dry when you built it? Did you build it in a humid shop and then he took it into his dryer house? All of these things contribute to wood movement.

That's a start - let's see what others say.

David


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## 0331reaperguns (Mar 13, 2019)

difalkner said:


> Welcome to the forum, Matt! When you get a minute add your location to your profile so it shows in the side panel. You can add your name to your signature line and it will show in each post.
> 
> Is there an actual finish on it or is it just stained? If it has a finish, did you finish both the outside and inside? Wood moves as it takes on and releases moisture and if the finish is only on the outside then the pieces are going to move more, usually cupping toward the finish side. Was the wood dry when you built it? Did you build it in a humid shop and then he took it into his dryer house? All of these things contribute to wood movement.
> 
> ...


Hi David, Thanks for the reply! I'll update my profile as suggested (I'm in Missouri). 

There isn't a finish on it per se (no poly, I was worried about adding an unwanted sheen). I pre-stained then stained the wood, wiped, and let dry. When I built the box the wood was from a local supplier and was dry, however it was in the heat of the summer and early fall and was very humid. Therefore my shop was humid. Yes, he displayed the box in his house and voila, it began to warp. 

Is there any chance the wood will return to its original shape should it be exposed to ample humidity? Would it be futile to try to 'steam' it back into shape and then seal it with poly (I'll take a little sheen for a functional piece any day)?


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## Steve Neul (Sep 2, 2011)

Sometimes wood will just warp no matter what you do. The finish and environment can also cause problems. The most common cause of warp is the wood wasn't seasoned or the wood was dried and then stored in a damp place which ran the moisture content back up. From there as with your cabinet when the doors are kept shut the exterior is exposed to more moisture than the inside. This creates an imbalance in moisture content from one side to the other. If you only used a wood stain on the cabinet and didn't seal it with anything that would enable the wood to absorb moisture from the air nearly as well as raw wood. If that is what was done then the combination of the wood being nearly raw and having the doors shut allowed the exterior of the wood to absorb more water. 
Now, if that is what is going on you could wet the concave side of the warped components and maybe flatten the wood. If then it does flatten you could put a varnish or some other finish on the inside and out and the wood might stay flat.


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## Jim Frye (Aug 24, 2016)

I once had a client company that made business show displays for large companies. Their stuff went through all sorts of environments and had to be stable from year to year. Their cabinet maker was emphatic about finishing. He insisted that all surfaces have the same finish inside and out to maintain stability over the years. I've followed that wisdom and never had anything warp or move. One additional thought on your issue. You used red oak, which is fine. However oak is a very porous wood. It has lots of rather large pores. Think of the wood as a bundle of straws. It takes a fair amount of finish to fill/seal those pores and if they aren't sealed, moisture (humidity) can get into/out of the wood easily. This is why sealing the oak (or any species) is important. Try this experiment. Take a small scrap piece of your red oak and stand it on end in a container with some stain in the bottom. Let it set for a few days and see where the stain goes. I use wiping varnish on projects which allows the first couple of applications to soak into the grain and seal it better. You can get varnish in different sheens, including satin, which has very little sheen. Just make sure you stir it often while using it. Oh yeah, I doubt the warped parts in your pipe box will straighten or flatten out on their own regardless of the humidity.


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## Brian T (Nov 3, 2018)

Water in wood is in two places:
Free water in the open cavities of the cells.
Bound water which is stuck in the walls of the wood cells.


When all the free water is gone, the wood feels and acts dry.
But with very low humidity, some of the bound water comes off and drifts away.
Now, the wood moves with the shrinkage stress.
Sadly, you cannot put the bound water back exactly where it came from.
What's done is mostly done, you'd have a devil of a time trying to steam bend and straighten those components.



Some people, like me, don't mind warping, just a sign of age ( like my guts).
I'd consider building another one, maybe apple? maybe cherry or pear?


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## epicfail48 (Mar 27, 2014)

Hey, not too far away from me, im in Springfield!

Wood moves, its the nature of the beast, so if youre trying to stop that entirely, well, may want to take up metalworking. That said, you can mitigate it. The first step is starting with wood thats been properly dried and acclimated. That step is the one that seems to get most people, if you try to use wood too soon after its been milled, odds are it wont have reached its final dryness. Buying from a good dealer and letting the wood sit in your shop to be certain is the best way to accomplish this, and to my ears this sounds like what you may have had happen to your box. Extreme warp generally has this at fault. 

Second thing you can do has to do with the finishing method; you need to make sure to balance the finish on both sides of a piece, and _in general_ a film finish will help slow wood movement the most by making it harder for atmospheric moisture to penetrate. In my experience, the first is more important than the second, a finished piece of wood will move the same as an unfinished piece, just slower, but a board thats had one side finished with the other side bare will very quickly turn into a potato chip. 

I will say that climate-wise, i havent had any major issues with my projects, provided the wood was properly dry to start. Really, unless youre moving a table top from florida to arizona, i wouldnt blame changes in climate for major warp. Sure, swings in humidity can cause some movement, but ive found the Missouri climate to be pretty stable as far as that goes, going from summer to winter or even from my stupidly humid basement to my very arid upstairs hasnt caused much in the way of movement with my projects. Like i said, id wager that the biggest issue was that your wood may not have been completely dry when you started working with it


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## epicfail48 (Mar 27, 2014)

Nearly forgot, i was so focused on the 'why' i forgot to weigh in on how to fix this:

Doubt you can, unfortunately.

After wood warps, theres not really a wap to un-warp it. Warp is wood was of assuming a position that balances its internal stresses, any way of flexing it back into shape is just going to reintroduce those stresses. Even if it works out that a change in humidity leads to the wood re-straightening itself, theres nothing you can apply to wood that will completely prevent moisture-based movement. Even a film finish like polyurethane will still allow moisture to permeate through, just very slowly. 

Overall, treat it as a learning experience. Now you know how wood movement can affect projects in the future, and you can start to take measures against it. First things first, let your wood sit before using it. Seldom it seems is wood completely dry straight from the lumber yard, and letting it chill out for a few weeks in your shop environment is hardly going to hurt it


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## woodnthings (Jan 24, 2009)

*Why wood warps ....*

The explanation by Brain T is great. Here's an article that goes into a bit more depth explaining that where the wood came from when cut from the tree is also important: 

https://www.popularwoodworking.com/article/why-wood-warps/


As explained, the moisture in the wood is located both within the cells and around the cells, free and bound. As the moisture leaves the wood from drying, it remains in the bound areas and leaves the free areas.... unevenly, depending on the cut, and the time and the degree of the drying process. Best to read the article. :vs_cool:


More information here:
https://theartofhandtools.com/why-wood-warps-and-how-to-fix-it/


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## Tennessee Tim (Dec 15, 2010)

Reaperguns,

Don't count it lost yet. There's one thing you can try and it works alot with boxes when MC changes. It's hard to tell from the pics BUT I'm assuming the joinery and grain direction are correct. With a enclosed box sometimes IF there's a large MC CHANGE the interior is slow to react. This can be cup or bow depending on whether opposite side gains or loses quickly/faster.

The trick I 've recommended several times and it worked is to open the doors and drawers and let acclimate for a week or more, usually the wood will rebalance and go back flat provided correct joinery. ONCE this is acquired, seal both sides to slow the MC changes keeping it more balanced......YES even after they're sealed MC still changes, the sealing just controls the speed of exchange!!!! ALWAYS remember wood is always alive and changes according to it's enviroment.

I personally likevthe Heritage Natural Finishes which have a softer satiny look unless you extremely build up. Autumn @ HNF is GREAT to help!!!

I'd try this first and it's simple!!!!!


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