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Panel bowed after planing...help?

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Forum topic by Phalanx1862 posted 02-26-2020 01:07 AM 474 views 0 times favorited 11 replies Add to Favorites Watch
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Phalanx1862

49 posts in 615 days


02-26-2020 01:07 AM

Topic tags/keywords: bow bowed flattening flatten panel

Hey y’all! Working on a clock build, the clock front will be made from a panel that I made from some qswo that I resawed and edge glued. I’m not so great at resawing, but I managed to get it to around 3/8 thick after planing. It was flat after planing, sat it on some stickers for a week. Problem is, this panel that I glued is now bowed in the middle by about 1/8 inch. Now, my question is, does anyone have any tricks for flattening a panel that is 12” wide without taking any thickness? Should I try to wet it down, and clamp it between cauls? In the end, I guess I can deal with it if I can’t get it flat, but it would make it easier to drill the hole for the dial if it was. Any help would be much appreciated.


11 replies so far

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CWWoodworking

1531 posts in 1194 days


#1 posted 02-26-2020 01:48 AM

Set it in the sun bow side up.

Don’t store panels flat. Especially thin stock.

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Phalanx1862

49 posts in 615 days


#2 posted 02-26-2020 02:01 AM

Thanks, I’ll give it a shot!

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Rich

6609 posts in 1604 days


#3 posted 02-26-2020 04:05 AM

It’s best to wait a few days after resawing before planing. For stock that thin, depending on how your piece is going to be constructed, it also might be possible to pull it flat during the glue up.

You can try the leave it in the sun suggestion, but another is to dampen the convex side and then weight it slightly curved the other direction using thin supports on the edges and a weight in the middle. The idea there is to soften the cells on the convex face and then compress them and let them dry that way. Done right, they’ll stay that way.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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Phalanx1862

49 posts in 615 days


#4 posted 02-26-2020 12:05 PM

Thanks bud! Being that it will be sitting with the edges just glued to the sides, I won’t have any frame to pull it flat. I’ll give this a shot before this weekend, if it doesn’t do it for me, I’ll try the sun trick. I enjoy having many options.

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Robert

4454 posts in 2496 days


#5 posted 02-26-2020 02:33 PM

In the future, keep panels clamped in cauls while acclimating. Not an absolute guarantee, but it has helped me.

I’ve tried numerous times, but I’ve never had luck with using sun/water trick. I know in the sun hard to know how long it can easily go the other way on you!! Usually I end up ripping the panel and regluing, or, starting over entirely.

I agree with Rich but also keep the panel as thick as possible as long as possible, rejointing and thicknessing in small increments, again, keeping in cauls between sessions.

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

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Rich

6609 posts in 1604 days


#6 posted 02-26-2020 03:12 PM


Thanks bud! Being that it will be sitting with the edges just glued to the sides, I won’t have any frame to pull it flat. I’ll give this a shot before this weekend, if it doesn’t do it for me, I’ll try the sun trick. I enjoy having many options.

- Phalanx1862

I’d make my suggestion the last thing you try. If your schedule allows it, let the boards sit for a few days in your shop. No stickers, etc, I just stand them up and leave them. Very often, the board will right itself. When it doesn’t, then you can start trying other things like those suggested here.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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SMP

3460 posts in 921 days


#7 posted 02-26-2020 03:19 PM

I recently had some QS cherry do the same thing, only more drastic of a bow. I’m talking if I put it convex side down, there is probably a 1/4” gap over a 3’ length. Isn’t QS supposed to be less likely to do this? I mean I would kind of expect this from sugar pine or something but I specifically went out of my way to get the QS cherry. Will try some of these fixes though.

View Bill_Steele's profile

Bill_Steele

754 posts in 2747 days


#8 posted 02-26-2020 04:54 PM

I’ve also experienced problems with warping after resawing and thickness planing. If I resaw a thick board (e.g. 6/4 or 8/4) there is often some type of warping that occurs to both halves—maybe not immediately but often after a day or two. If I run a board through the planer, but plane one side more than the other (i.e. more passes on one side) then I find that I often get some warping.

What I’ve found is that I get better results when I plane both sides of the board about the same number of passes—this also applies to the drum sander.

When resawing I assume that there will be some warping and I leave enough material (e.g. ~ 1/4”) so that I can joint and/or plane to the desired thickness. This applies mostly for stock that I want to be between 1/4” – 1/2” in thickness.

For shop sawn veneer, I just slice it off an S4S board maybe a 1/16” thicker than I need and then drum sand it to final thickness.

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Phalanx1862

49 posts in 615 days


#9 posted 02-26-2020 09:39 PM

Thanks everybody! Y’all definitely gave me some ideas, and I’m not in a total rush, I have other small projects I can do while I try to get it flat again. If worse comes to worst, I have backup stock that I can use, I was just trying to save this one because of how well the grain matched, AND it’s already glued up. Anyways, thanks!

View CWWoodworking's profile

CWWoodworking

1531 posts in 1194 days


#10 posted 02-26-2020 09:55 PM

For people that run through planer, do you plane more on one side than other?

I make some rough sawn tops. Order the boards planed one side. Occasionally I will get a board that is cupped/bowed.

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Andybb

3171 posts in 1618 days


#11 posted 02-26-2020 11:34 PM

If I’m not going to use it immediately anything I resaw gets put between cauls and using a trick I learned from rich they get tightly wrapped with stretch wrapping tape. After wrapping I put them in a plastic bag full of sawdust which helps absorb residual moisture.

-- Andy - Seattle USA

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