bar top is cupping

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Forum topic by Christopher Frank posted 06-01-2013 05:39 PM 1171 views 0 times favorited 5 replies Add to Favorites Watch
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Christopher Frank

11 posts in 3744 days

06-01-2013 05:39 PM

So ive installed a 21’ bartop. I had finished the underside prior to installation. So I’ve lost mor moisture out of the top. is it possible to reintroduce moisture back into the top and alleviate the cupping?

5 replies so far

View Loren's profile


10250 posts in 3611 days

#1 posted 06-01-2013 07:28 PM

No. Wait until it stops moving, then flatten and refinish.

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Matt Rogers

109 posts in 1933 days

#2 posted 06-01-2013 08:57 PM

I disagree with the previous poster. You can certainly re-introduce moisture into the top to get the top to flatten out. That does not mean that it will not turn back into a potato chip later on, but if the top is relatively thin compared to the strength of the base/supports, you can get the top flat enough to fasten it in place and it may remain flat while it equalizes its moisture content.

You need to specify the materials used in the top and the base construction for a better answer. If the top is a 3” thick oak slab, then nothing is going to stop it moving, but it if it is a 3/4” glue up panel, you can probably fasten/re-fasten it flat onto a strong base and keep it flat.

It you do have a thick slab of wood and you need it to be dead flat, then wait for a while (months) and then remove the slab, flatten both sides and re-install.

-- Matt Rogers, and

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404 - Not Found

2544 posts in 2933 days

#3 posted 06-01-2013 11:47 PM

From the sound of it, did you use a wide plank with the heart side down?

I think if you stripped the top down and wet it it might flatten out, but as Matt says, it will probably cup again. You could try putting some half thickness cuts lengthways in the underside, like they do with wide skirting boards, it would help.

View bonobo's profile


297 posts in 2020 days

#4 posted 06-01-2013 11:58 PM

I’d probably wait for it to cup as much as it’s going to and then hand plane it flat and you’d lose some thickness doing that, so if that,s a problem, you could cut a lot of lengthwise kerfs and fill those with glue.

-- “The easy confidence with which I know another man's religion is folly teaches me to suspect that my own is also.” ― Mark Twain

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Christopher Frank

11 posts in 3744 days

#5 posted 06-08-2014 01:21 PM

So I should have replied to this a year ago. I solved the problem! Using a spray bottle, I misted to topside of the bar top and covered it with painter’s plastic. I did this repeatedly for about two days and it eventually relaxed and laid flat again!Disaster was averted and lessons were learned!

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