# kerfing cupped boards



## wingnut57 (Nov 16, 2009)

Hello! I'm new to this forum but I hope to visit often.
I have purchased two oak boards that are 14.5"x 12'. They have a slight cupping going on and I want to kerf the bottom sides, flatten them out to an anchor and glass the kerfed side to prevent them from cupping anymore. 
These are free floating shelving, I can add a few screws if I have to about 1/3 from each outer edge but would rather not.
Any help would be greatly appreciated.
Mike


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## 12penny (Nov 21, 2008)

wingnut...I dont get the anchor and glass part.

How thick are they?


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## woodnthings (Jan 24, 2009)

*He means....*

Make a saw kerf on the bottom, up and almost through the board and then fiberglas the kerf after flattening them as with a heavy object "anchor" or weigh/ anchor them down. I think?:blink: 
I also think you are just better off to saw right through the board with an accurate glue line blade/cut and just glue them back together. It will be an almost if invisible joint. The thickness doesn't matter too much, but you may experience more cupping, depending if the board is plain sawn or quarter sawn. If the growth rings are symetrical about the center of the board, then cupping is likely. But the above will remedy most of it. The top and bottom of the board is drying at a slightly different rate. Sounds like nice wood however. Consider a drum sander or wide belt sander if the glue joint isn't perfect. Of course hands tools or portable will also work. good luck. :thumbsup: bill


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## trimworks (Nov 15, 2009)

I would it and purchase some with no cup. Always check your grain before you buy your lumber. And then it still may cup on you.


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## woodnthings (Jan 24, 2009)

*Huh?*

I would.......... it and purchase some with no cup.??
"Return?"

Any wood in that width 14.5" is bound cup eventually, The best remedy is to straight line rip and glue it. :yes: bill


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## 12penny (Nov 21, 2008)

I agree with woodn...split in half, surface if you want and glue back together. If its 4/4 or 5/4 you might be able to have them thickness sanded without cutting them in half. Dont know how bad the cupping is as to wether that would be an option.


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## wingnut57 (Nov 16, 2009)

12penny said:


> wingnut...I dont get the anchor and glass part.
> 
> 1" thick.
> The glass should act as a stiffback "kinda" if I fill the kerfs with it. The glass should adhere the boards preventing any more movement in any direction and anchor them to something flat until the glass cures.
> I use to build some wrecked cars so glassing is an easy step


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## Jacktoo (Oct 8, 2009)

I agree with ripping and gluing first, but if this is not an option, sometimes this will help. Try laying the board cup down on a concrete floor overnight. If you notice it getting better, leave it for a few days. This works best in a heated shop because the edges generally move towards the heat source and the concrete is trying to draw the moisture out of the wood. Unfortunately it doesn't always work, but if it did, look at all the time we would all save looking for that perfect board.


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## woodnthings (Jan 24, 2009)

*How the board was sawn is important*

ooops brain fart posted to the wrong thread, still good info tho....

Check this article: http://www.allwoodwork.com/article/woodwork/plainorquartersawn.htm
If the end of your board look like a bunch of smiles it's plain sawn and likely to cup. If the grain is mostly perpendicular to the wide surface of the board or vertical, it's quarter sawn or very close and likely not to cup. So use the best boards if possible.
 bill


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## xelntchance (Jan 2, 2008)

*define free floating ?*

How are you planning to stick 2, 12 ft. oak planks to the wall? And hope to stack heavy ,sh....stuff on. :blink:
14.5 inches wide. How long are the screws :huh:



wingnut57 said:


> Hello! I'm new to this forum but I hope to visit often.
> I have purchased two oak boards that are 14.5"x 12'. They have a slight cupping going on and I want to kerf the bottom sides, flatten them out to an anchor and glass the kerfed side to prevent them from cupping anymore.
> These are free floating shelving, I can add a few screws if I have to about 1/3 from each outer edge but would rather not.
> Any help would be greatly appreciated.
> Mike


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## woodnthings (Jan 24, 2009)

*wingnut has left the building...*



xelntchance said:


> How are you planning to stick 2, 12 ft. oak planks to the wall? And hope to stack heavy ,sh....stuff on. :blink:
> 14.5 inches wide. How long are the screws :huh:


I don't think he's going to answers you questions the post is almost a year old. He gone.


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