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Egg Spurt
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Discussion Starter · #1 ·
So I recently bought about 20 bf of 1/2" red oak, but didn't pay attention to the ends.. Turns out its all rift cut and already cupped a week later.. I suppose I'm going to plane it all down to probably 3/8ths and hope for the best.. Just for a bunch of small kitchen boxes for utensils and such..I just don't fall in love with dragging out the heavy ass planer.. I still don't have room for a cart for it..
 

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Not sure if the planer will do any good other than making a thinner board and it will probably cup again.
Anyway, I wish you luck. I'm fortunate in that that hasnt happened since I gave up using pine over 40 years ago.
 

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where's my table saw?
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I would rip down the lengths either in half or thirds and glue together. The edges may not mate together perfectly because of the cup, so pay close attention there and joint or rip again shaving a tiny amount off. I made these "gluing clamps" for exactly this type of glue up:

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Oak? Ripping cupped lumber will create junk.
You neversaid what the dimensions were.
I suggest that you build a steam chest. Cut some oak to length++ and steam it but good then into some sort of a press to cool.
 

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Cabinetmaker
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The cupping was probably due to being stored in a damp environment, before you purchased it (and/or it was stored upright, instead of flat). When you brought the boards inside, it dried out and then cupped. I recently had the same problem with a small supply of 3/4" oak boards. To resolve the problem, I laid the boards (separately) and cupped-side down on a concrete garage floor. The cupping disappeared 2 days later. I then took the boards off the concrete, stored them flat on a lumber rack and they remained flat, ever since. I just used some of the boards recently (after 1 month) and had no problems with warping. It's not to say that it will work for you, but I'd give it a try. It may save you time, waste and further frustration.
 

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Oak? Ripping cupped lumber will create junk.
You never said what the dimensions were.
I suggest that you build a steam chest. Cut some oak to length++ and steam it but good then into some sort of a press to cool.
Oh contrare! What WNT said works.

I've done it more times than I can count, both individual boards and panels.

A lot easier than steaming..................but whatever works.
 

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So I recently bought about 20 bf of 1/2" red oak, but didn't pay attention to the ends.. Turns out its all rift cut and already cupped a week later.. I suppose I'm going to plane it all down to probably 3/8ths and hope for the best.. Just for a bunch of small kitchen boxes for utensils and such..I just don't fall in love with dragging out the heavy ass planer.. I still don't have room for a cart for it..
If you have the time you might stack and sticker the wood for a couple weeks and see if it flattens itself out.
 

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Egg Spurt
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Discussion Starter · #9 ·
Maybe plain sawn .Either way they're flat for now. I only took off about 1/64th.a few are slightly rounded at the edges, but that's getting ripped off anyway.. Laying flat on the saw with a couple of paint cans on them just in case..
I need to make a trip to a scrap yard for a few heavy steel blocks or chunks of I beam for holding things down every now and then. Paint cans ain't that heavy.
We have had a lot of rain this summer and now things are starting to dry.. I've had a few different things warp and cup more than usual this season.
 

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Egg Spurt
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Discussion Starter · #11 ·
Thanks for the correction.. I'll file it away in the vast empty spot between my ears..
 
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If you were to take a board that has been plain sawn and looked at edge you will see the rings in a partial to full curve. The rings will want to straighten out or flatten out and that will be the direction of the cupping. Seems to be contrary to what we would expect.
 

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Egg Spurt
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Discussion Starter · #13 ·
If you were to take a board that has been plain sawn and looked at edge you will see the rings in a partial to full curve. The rings will want to straighten out or flatten out and that will be the direction of the cupping. Seems to be contrary to what we would expect.
Kind of like a flower unfolding. Both are in the plant kingdom.. Makes sense in a way..
 
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