Don't know what happened


Chet

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18 hours ago, Chet said:

The piece that is cupping in the opposite direction has the same kerfs.  The kerfs have been there 5 days and it just happened over night.

I'm in SoCal and so, like you I don't often have humidity issues one way or the other on the scale that somewhere like the southeast might.  Since it behaved itself for days my guess is that something happened to the weather and your panel became your barometer for that condition.  Certainly leaving a panel flat on a surface with only one side exposed to the air can focus that behavior but, like I said, out here on the left coast we get away with things that other parts of the country do not.

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On 7/9/2017 at 8:57 AM, gee-dub said:

I'm in SoCal and so, like you I don't often have humidity issues one way or the other on the scale that somewhere like the southeast might.

This is the first time I have ever had this happen but I will take proper measures moving forward.  I like to think I am smart enough to learn from my first mistake.  But the real puzzle to me continues to be that the two bowed in different directions and the third not at all.  We did have a big drop in humidity over the week end and it is now back to seasonal normals.  We'll see.

Thanks to everyone for chiming in.

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12 minutes ago, Chet said:

But the real puzzle to me continues to be that the two bowed in different directions and the third not at all.

Three boards, three reactions.  It's like having a bowl of fruit...some will taste better than others, some will spoil sooner than others, etc.  It's a natural material.  Wood can behave in mysterious ways.

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On 7/8/2017 at 7:40 PM, Eric. said:

Every piece of wood is unique and will react to an environmental situation differently.  You can't predict what they'll do.  Just gotta treat them right and hope for the best.  Consider them women.

Well I may as well quit woodworking then... it's enough work keeping my wife happy, let alone all that wood in the garage, too!

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On 7/8/2017 at 7:55 PM, C Shaffer said:

Never leave it lay on a bench. This is classic moisture. The kerf allowed lots of evap from exposed end grain. The board tight to the bench traps it in. Always sticker, and even turn the kerf down. 

Ok,I'm a newbie and was reading this thread. What does sticker and kerf down mean?

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Kerf is in reference to the groves I had cut in my panels.  The kerf is generally the width of the saw blade.  Stickering is a process of stacking you wood on thin sticks so it gets air flow around all parts, this help it adjust to the humidity during the process of milling.  It is also used in the initial drying of lumber.  See the picture below,  (not my shop)

a_milled.jpg

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Kerf.......The space behind your saw after you cut, with a standard blade your kerf is 1/8th   Sticker.......putting a small narrow piece of wood  under the wood you just cut, in order to keep air flowing all around the piece, keeping a balance of the moisture in your work piece.

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2 minutes ago, RichardA said:

Kerf.......The space behind your saw after you cut, with a standard blade your kerf is 1/8th   Sticker.......putting a small narrow piece of wood  under the wood you just cut, in order to keep air flowing all around the piece, keeping a balance of the moisture in your work piece.

Thanks so wood I won't be using a while but likely will in the future isn't ok to just be stacked or laid against a wall it should have the wood spacers? Glad I found this out now and glad I just bought 100 mixing sticks!

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1 hour ago, Dhankx said:

Thanks so wood I won't be using a while but likely will in the future isn't ok to just be stacked or laid against a wall it should have the wood spacers? Glad I found this out now and glad I just bought 100 mixing sticks!

Laying boards flat and stickered is better than leaning them up against a wall, and it takes up less space.  If you have some giant panels you're working with, different story.  The most important part is keeping equal air flow on both sides at all times.  Sometimes if I'm just ending work for the night I'll just set smaller boards on edge if I only have a few parts on my bench.  But ordinarily my parts stay stacked and stickered throughout an entire build.  I don't even like them laying flat for an hour.  Doesn't take long to knock them out of equilibrium and once they warp, you're usually screwed.  It becomes second nature eventually.

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Spray the wood with water, it goes back to flat, it's a moisture issue. If they remain bowed, its tension in the wood that was released and probably unusable.  

 

Put the piece in a plastic bag it may go back to flat. And keep in the bag until your ready to assemble. 

 

-Ace-

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5 minutes ago, AceHoleInOne said:

Spray the wood with water, they go back to flat

It might go back to flat...until it dries out...and goes back to cupped again.  Once a piece of wood takes on its desired form, it's difficult to make it go back permanently without milling it.

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Just now, Eric. said:

It might go back to flat...until it dries out...and goes back to cupped again.  Once a piece of wood takes on its desired form, it's difficult to make it go back permanently without milling it.

Understand that. But if you get the piece back to flat, you know it's a moisture issue and not tension. If you can get it back to flat, you can work with it and hopeful lock it down in your project, thus limiting the movement. Not sure what this project is, I may of missed that part. With all the kerfs as cut, the wood could remain stable in the project?

 

-Ace-

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3 minutes ago, AceHoleInOne said:

Understand that. But if you get the piece back to flat, you know it's a moisture issue and not tension. If you can get it back to flat, you can work with it and hopeful lock it down in your project, thus limiting the movement. Not sure what this project is, I may of missed that part. With all the kerfs as cut, the wood could remain stable in the project?

 

-Ace-

I'll believe it when I see it. :)

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When I was a know-nothing noob I tried a bunch of that trickery with warped boards (this was before I understood wood at all)...and of course none of them worked.  The moist bag, the heat gun, the dewy meadow under the sun, the wet and clamp...all of them.  Never worked.  They'd go back to flat temporarily - occasionally, rarely...then they'd spring right back to potato chip once they dried.  I've yet to see anyone successfully permanently flatten a board with moisture...but I'm ready and willing to be proven wrong.

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When I was a know-nothing noob I tried a bunch of that trickery with warped boards (this was before I understood wood at all)...and of course none of them worked.  The moist bag, the heat gun, the dewy meadow under the sun, the wet and clamp...all of them.  Never worked.  They'd go back to flat temporarily - occasionally, rarely...then they'd spring right back to potato chip once they dried.  I've yet to see anyone successfully permanently flatten a board with moisture...but I'm ready and willing to be proven wrong.

 

 

 

Ok, purely anecdotal, but here goes ...

 

 

The first "Fine Furniture" project I ever made was the classic Shaker side table. The drawer bottom was a panel of maple that I had re-sawn to a about 5/16 strong. I glued the panel up before going to work, and it was nice and flat when I got home. I unclamped and scraped away the squeeze-out, but left it lying on the bench. Couole days later, it looked like a pringles. I flipped it over, and after a day or so, it flattened out, but by week's end, it tater chipped the other way!

 

I flipped it again, and it slowly came to rest flat on the bench, at which time I installed it into the drawer, before it curled up again. Been fine ever since.

 

 

When I say curled up, I mean 2 opposing corners were off the bench by 1.5 inches, in a 10 x 14 panel.

 

 

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11 minutes ago, wtnhighlander said:

at which time I installed it into the drawer, before it curled up again. Been fine ever since

Yeah, because it's trapped in grooves.  If you'd have just left it laying around I'm sure it would still be a Pringle today.

Thin panels are tough to keep flat no matter what you do.  The point of the whole thread is sticker your boards to stack the deck in your favor.  Sometimes they'll warp a little anyway, but at least you're doing what you can to help them stay flat if that's their natural inclination.

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No need to sticker, upon cutting those kerf's, if the board remains flat, its a moisture issue. So by placing the board in a plastic bag after cutting. The moisture content remains the same, no cupping. When I cut raised panels, rails and stiles. I try to immediately assemble the doors. If I can't and need to wait a day or two, I bag them to eliminate moisture movement. Once locked in, your good to go in most cases.  

 

-Ace-

 

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I stickered the three panels after I posted this.  As I said then, we had had a pretty weird, for here, humidity swing.  Weather is back to normal for Norther California, I was out of town for a few days but when I got back, this-IMG_5631.jpg

Now is back to looking like this-

IMG_5632.jpg

It still has a touch over a 1/32 of an inch bow, but I can work with that.

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