How to remove tension from burl

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Forum topic by gdiddy13 posted 05-16-2022 01:07 AM 437 views 0 times favorited 9 replies Add to Favorites Watch
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67 posts in 2237 days

05-16-2022 01:07 AM

I have a maple burl

that once I had resawn it, it then had a lot of tension and wants to curve or bowl up.

I had it in the sun all day and clamped it but as soon as I took it out it went back to its previous state.

Any tricks other than relief cuts to flatten this guy?


9 replies so far

View Aj2's profile


4492 posts in 3292 days

#1 posted 05-16-2022 01:13 AM

If you take away some of the wood from the right side of the board as shown in the pic. Start a flat area in the middle as best you can. You will probably see it start to straighten out before you even make it to the ends.
You will loose some thickness but it’s a fair trade.
Check moisture too
Good Luck

-- Aj

View Phil32's profile


1802 posts in 1397 days

#2 posted 05-16-2022 10:19 PM

What are the present dimensions of the piece?

-- You know, this site doesn't require woodworking skills, but you should know how to write.

View gdiddy13's profile


67 posts in 2237 days

#3 posted 05-16-2022 10:27 PM

It’s roughly 27”x12” and 1.25” thick

View Vandon's profile


106 posts in 889 days

#4 posted 05-16-2022 10:50 PM

What do you plan on making with it?

View gdiddy13's profile


67 posts in 2237 days

#5 posted 05-16-2022 11:11 PM

I just need it flat for some epoxy molds. If not, and if the epoxy is t thick enough, it will make the board start to curl as well

View Lazyman's profile


9779 posts in 2881 days

#6 posted 05-17-2022 12:53 PM

If it wants to warp, there is nothing you can really do to stop it that doesn’t risk other problems. Did it curl immediate during or after cutting or was it after it sat for a while? If immediately, then it may be tension but if it took some time (even as little as 15-30 minutes) then it is uneven drying. If laying it in the sun straightened it, then I think it is probably drying that is causing it so it may just need some time for the moisture to equalize. You will want to let it sit for a while and monitor the moisture content before you use it anyway. Make sure that you allow air to flow around both sides while you wait. Sticker it if flat or lean it against the wall.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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67 posts in 2237 days

#7 posted 05-17-2022 12:58 PM

It started to curl immediately after it was resawn, was pretty flat before that.

View Robert's profile


5008 posts in 2974 days

#8 posted 05-17-2022 02:05 PM

Burl isn’t really wood like we think of wood. Its extremely irregular with stresses going any which way.

That said, most likely a moisture issue. Expanding on what Lazyman said, understand as wood dries the stress is released, to in every case of bowing or cupping, its as much a stress issue as a moisture issue.

You could try steaming it, but in the end I doubt anything will work other than “breaking its back” with release kerfs.

-- Everything is a prototype thats why its one of a kind!!

View gdiddy13's profile


67 posts in 2237 days

#9 posted 05-17-2022 02:44 PM

Good insight and kinda what I was thinking. Thanks!

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