# Help ... warped cutting board



## RobH2 (May 11, 2008)

I'm having a problem with this board warping and wondering if anyone has repair suggestions. I made the mistake of shellacing one face only and as a result the base is expanding. What should I do now? Soak and clamp it? Plane it flat again? Burn it and make another one?!!!! In the pic you can see the left side lifting up from the counter. All of the corners do this making a board that rocks really well. Perhaps I should build a chair for the top and repurpose it


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## lew (Feb 13, 2008)

When I made some of these, they warped during the sanding process. I was trying to sand one side thru a grit before starting the other. The heat build up on one side and not the other was causing the problem.

I realize this is not your situation but I was thinking maybe heat- and correspondingly dryness- could reverse your problem. Maybe placing it in a warm oven- bowed side up and weighted to force it down might work. I have never tried this but…...


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## dennis (Aug 3, 2006)

I have 36 grit for my belt sander for just such problems.


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## closetguy (Sep 29, 2007)

Turn it over on the other side and leave it for a few hours. I have experienced this with very large boards. Flipping them over for a while sometimes causes them to flatten back out.

Why did you shellac it? Knifes will cut the finish. You need to sand that off and coat it with mineral oil.


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## childress (Sep 14, 2008)

You might also try to clamp the board over night to your workbench (or table or counter) with a stick under the middle section. Clamp it just over flat (in the other direction) and see if that helps. That has fixed quite a few of my boards in the past. You can also get rubber feet at your local hardware store to lift the board (and help it stay put on the counter) off the counter so if it cups again, you will still have the four feet keeping the middle off the counter.

If you continue to have this problem, it might be due to thickness. I've noticed anything under 1&3/8" will have a tendency to warp easier unless it's a small board. What are the dimentions of your board?


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## sandhill (Aug 28, 2007)

I would resurface it and level it as you go. I use mineral oil and bees wax but I would think on some thig that small the finish would not make that much difference.


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## jm82435 (Feb 26, 2008)

I think the lesson here is: whatever you do to one side you need to do to the other. Especially when dealing with so much end grain such as these cutting boards. I always try cutting equal amounts off of both sides whether planing or sanding. The problem here I am sure is (as you alluded to) that you finished only one side. I would give the other side equal treatment and see if it does not flatten out by itself.


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## RobH2 (May 11, 2008)

Childress,
I followed your advise and it worked perfectly. I scraped off the shellac, then clamped it to my bench with a small board underneath. It bowed the board the opposite way and after a day or so when I removed the clamps it was as flat as it ever was. This time I used mineral oil on all surfaces and it seems to be holding up fine. Thanks for your help.
Rob

About mineral oil; does anyone know how to cut it thinner? I want to help it absorb deeper.


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## marcb (May 5, 2008)

Don't use a film finish on cutting boards. Mineral oil only.

The chopping will nick the finish causing a gouge where bacteria can grow. Mineral oil fills in imperfections in the wood, keeping this from being an issue.


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## joevt (Jan 9, 2009)

Dont thin mineral oil, heat it. It should thin and be better absorbed.


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## Akallen (Feb 16, 2009)

I had a similar problem some years ago with a 24" x 60 " butcher block table I made for my wife. I ended up cutting saw kerfs in the concave side my skilsaw, then on my table saw I cut wedges a hair wider than the saw kerf on the fat edge tappered down to a hair less than the kerf on the skinny edge. I lined up my skilsaw blade with a glue joint on the butcher block and cut the kerfs about 3/4 of the way through the thickness of the top. Then, I was able to clamp the board flat to my workbench, rub some titebond III on the wedges and insert them into the kerf and pounded them in with a board between them and a rubber mallot. Whatever was left sticking up, I sanded off. Yeah, it leaves an ugly edge but I then ran a band around the edge made of the same material as the table (maple). After sanding and oiling, you have to look pretty hard to see the wedges. And, it's now flat!!


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## sandhill (Aug 28, 2007)

I just found this fix and it works great…Seal the convex side with the same finish as the surface to balance out the top.


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## BlueStingrayBoots (Jun 11, 2007)

Take an axe to it cheif! and some whole chickens beef ribs pork ribs etc. Once you smell the food on the grill, that board will be the last of your worries. If that board doesn't hold up to the chopping then yea, throw it in the fire.


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## RobH2 (May 11, 2008)

Um, I'm a vegetarian and I have plenty of firewood but thanks anyways


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## RobH2 (May 11, 2008)

I guess I'm the one that brought up burning it in the first place! Funny how you forget what you said 40-some days ago!


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## BlueStingrayBoots (Jun 11, 2007)

I wasnt very serious Rob, just wet it and use strips of wood and c-clamps or place it on otherside to let dry. I'm not sure but check the stability of the wood choices.


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## RobH2 (May 11, 2008)

No I'm sure you weren't serious. It was kind of funny to me just how unapplicable your comment was to my situation, but of course how could you really know those things.


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## country_jock (Mar 3, 2009)

Childress,
I have a similar problem to Rob. My new kitchen doors of red oak have bowed since putting them together. Each board is 2-4". I tried to alternate the grain. I used biscuits and glue to make the needed width. I have put stain on the back of the doors but have not gotten the fronts stained yet. Could that be my problem?

The doors are 3/4" finished width red oak with hidden hinges already on them and hanging. With only 3/4" material, I am afraid to sand the center down to get the bow out. You mentioned using a board in the center clamped to a bench overnight. Do I turn the bow up or down?


> If the bow is up, wouldn't that prevent the center from dropping down amd linng up correctly


 I'm confused.

Thanks.
Country_Jock


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## Karson (May 9, 2006)

I would sand it flat.


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## childress (Sep 14, 2008)

Well, country jock, this technique works best with an end grain cutting board. because it's ALOT harder to control warping with the grain. You see, with a cutting board, the grain is only 1&1/2 long (or so), and when you clamp it like I said, your not really forcing the grain of the wood to change shape, your forcing the board. With your doors, I don't think clampimg them will help (but you can try, it doesn't hurt). Sanding like Karson said or first finish staining and laying flat for a day or so. Part of the problem may have been how the doors acclimated to your house conditions. And it sounds like you made them completely solid, right? I think this why doors are usually made with stiles, rails and panels….to help prevent this.


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## skywalker01 (May 19, 2009)

Well, I'm revisiting this one because I am having a similar problem with the top to my knitting box. It keeps wanting to cup on me and boy is it becoming a disaster. I made this cutting board too. Looks like the wood whisperer version… If not it looks similar. I have now built 5 of them and have the same problem on all of them. I used different woods on each one also and still have the problem. They get wet a lot so you would need to keep them really well sealed with the mineral oil to never get that warpage. Whatever you do don't sand it flat. What you would then be doing is just temporarily removing the high spots until it decided to move again which could then really make it look bad and if you sanded again then your just opening up more cup, bow, warpage. I found that adding little rubber feet of some sort to one side and then always placing it down on them keeps it off of water and such. Another note, we used to put them on the table then put a pot holder on them and then a super hot pot while eating dinner or w/e. WOW! It would get so warped it was amazing. I've even had mine split near the joints because of this. Needles to say I don't do that anymore. And about finishing with mineral oil, I would rather use a poly finish that is thinned down. Once it dries all the harsh stuff is evaporated. It repels liquids, all the others soak them in, and if you make a cut with a knife it will leave a small scratch in the surface whether you use poly, mineral, nothing, salad bowl finish, or w/e. Check out charles on this youtube video. 




 , THANKS!


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