Warped Cherry

[Khb1526]

I am new to buying rough lumber and I bought some wide cherry boards from Gibsonville this weekend to make a writing table. They did not have a good selection of the regular 4-8" wide boards, so I ended up buying some of the 10"+ boards(and paying $2 per foot more). Well I get them home and cut a few pieces that I needed to get started and noticed they were warped. I cut them about 60 inches long and if you lay them on a flat surface, the center of the board is about 1/4"+ off the surface. Did I do a bad job of picking out my wood or is this pretty normal? Should I scrap these pieces and buy better boards?

Secondly, I was planning to make the top out of 4 to 5 six inches wide boards, but I bought a pretty nice 13" wide board. The top is 22" wide, so I could just rip the board down to 11" and join two boards to make the 22". Should I rip the boards down to 5.5 inches to keep them from cupping? It looks pretty good now and it has been in my basement workshop since saturday.
Thanks for your help!

 

[Mike Davis]

You'll need to joint that board to get the warp out. If you don't have a wide jointer just hand plane the high spots then run it through the planer.

If the 13 inch board ain't cupped now, it probably won't cup. Just plane it equally on each side and give the air equal access to both sides.

Cutting a wide board won't help to keep it from cupping.

 

[Travis Porter]

What you have isn't unusual. Twist is what you want to avoid.

As for what to do, it depends. How big of a jointer do you have (if any)? As for the wide boards with the cup, depending on the grain pattern and your jointer size/availability, I would rip them down the middle and joint and plane them then glue them back together. As for your top, sure you can do that, just be sure to fasten it to the cabinet before too long so it doesn't warp.

 

[mkepke]

<snip>
Secondly, I was planning to make the top out of 4 to 5 six inches wide boards, but I bought a pretty nice 13" wide board. The top is 22" wide, so I could just rip the board down to 11" and join two boards to make the 22". Should I rip the boards down to 5.5 inches to keep them from cupping? It looks pretty good now and it has been in my basement workshop since saturday.
Thanks for your help!

Never cut down a wide board if you can avoid it. Make the top out of the two 11" boards.

By the way, the stock you bought should sit in your basement for a couple *weeks* before you start working it, in order to give the stock time to acclimate to your shop.

Once you get these boards surfaced take precautions to minimize the chance of warping ! Either attach them to the table carcass just after you finish final dimensioning, or clamp them up with temporary cleats until you're ready to attach the top.

-Mark

 

[DaveO]

Wider flat sawn boards have a greater chance of cupping because there is more of the center of the tree in them, and more surface to cup. As Mike said if the boards are flat they will probably stay that way. But if they are cupped the best thing is to rip them down the center, (assuming you don't have a wide jointer like Travis) joint the two halves flat and then glue them back together. Intentionally ripping a flat board into smaller boards and gluing them back together for the purpose of preventing cupping is a wives tale. The board will act the same way as it would when it was whole.
I have just done a similar job with some wide Cherry I got. With only a 6" jointer I had no choice but to rip, joint, plane and glue back together. But I think the results came out excellent.
http://www.ncwoodworker.net/forums/f29/cherry-stereo-cabinet-wip-19957/


Dave

 

[jeff...]

I was talking to FredP last weekend while unloading some oak, I some of the wide boards had splits down the center. I told Fred I don't know why I cut wide oak boards because most of them want to split anyways. Fred told me he rips the splits out and glues them back together. Makes sense... then I asked him wouldn't it just be easier to glue narrower boards together to make a wide one? and FredP said (Fred please insert answer here)

 

[Jim Murphy]

I'll join the parade of preferring to glue up narrow boards instead of dealing with wide ones. It seems to me the wider the board the greater the amount of cup, bow or twist to deal with, especially aggravating little amounts of twist. You burn up half the thickness getting the twist out of a wide board.

And yes, they split, so you cut out the splits and glue back.

I have a different take from Mark. I'd rip those 11"ers in half, joint, swap ends, flip faces and glue up, especially if you're looking for stability instead of appearance.

 

[Khb1526]

You'll need to joint that board to get the warp out. If you don't have a wide jointer just hand plane the high spots then run it through the planer.

Thanks for your advise, but the boards are already planed to thickness. So if I try and get the high spots out, I will end up with a thinner board.

 

[Khb1526]

Wider flat sawn boards have a greater chance of cupping because there is more of the center of the tree in them, and more surface to cup. As Mike said if the boards are flat they will probably stay that way. But if they are cupped the best thing is to rip them down the center, (assuming you don't have a wide jointer like Travis) joint the two halves flat and then glue them back together. Intentionally ripping a flat board into smaller boards and gluing them back together for the purpose of preventing cupping is a wives tale. The board will act the same way as it would when it was whole.
I have just done a similar job with some wide Cherry I got. With only a 6" jointer I had no choice but to rip, joint, plane and glue back together. But I think the results came out excellent.
http://www.ncwoodworker.net/forums/f29/cherry-stereo-cabinet-wip-19957/


Dave

Project looks good. If the board stays flat, I will probably just use the 11" inchers and cross my fingers!

 

[Khb1526]

What you have isn't unusual. Twist is what you want to avoid.

As for what to do, it depends. How big of a jointer do you have (if any)? As for the wide boards with the cup, depending on the grain pattern and your jointer size/availability, I would rip them down the middle and joint and plane them then glue them back together. As for your top, sure you can do that, just be sure to fasten it to the cabinet before too long so it doesn't warp.

I do not have a jointer...looking for a used one if anybody has a good deal!

I guess everyone was assuming the boards were not planed yet since I said I bought rough lumber, but I had them planned & strait edged in Gibsonville(I thought that was a deal at $.40 per foot). It sound like I will need to address warp and cupping before planning. So is there anything to do with the warp in my boards besides jointing then planning and having a 5/8 inch board instead of 3/4?

 

[mkepke]

I'll join the parade of preferring to glue up narrow boards instead of dealing with wide ones. It seems to me the wider the board the greater the amount of cup, bow or twist to deal with, especially aggravating little amounts of twist. You burn up half the thickness getting the twist out of a wide board.

And yes, they split, so you cut out the splits and glue back.

I have a different take from Mark. I'd rip those 11"ers in half, joint, swap ends, flip faces and glue up, especially if you're looking for stability instead of appearance.

Eeek. Jim, how can I convince you of the error of your ways ?

I agree that as the boards get wider, there tends to be more warp (it's just accumulated) and its obviously harder to get the warp out since 12" jointers are harder to come by than 6" jointers. At some point, the stock is unworkable and you must cut the stock down.

But if you *can* flatten a 11" wide board, you should.

-Mark

 

[mkepke]

<snip>
I guess everyone was assuming the boards were not planed yet since I said I bought rough lumber, but I had them planned & strait edged in Gibsonville(I thought that was a deal at $.40 per foot). It sound like I will need to address warp and cupping before planning. So is there anything to do with the warp in my boards besides jointing then planning and having a 5/8 inch board instead of 3/4?

Keith..you said before that the boards only have 1/4" of warp over 60". This can probably be controlled mechanically (as opposed to jointing the boards down to something less than 3/4").

How much force (estimate) do you need to weight down the center of the boards and remove that 1/4" warp ?

If the answer is "not too much", you can probably eliminate the warp by the method you attach the top to the table carcase. Assuming you are building a conventional table with a stretcher frame, you can use mechanical connectors (screws, button-blocks, etc) between the stretchers and the top to pull the top flat against the stretchers.

-Mark

 

[Mike Davis]

Right,

and if the cup is not too bad you can cut the board down the center flip one board and glue it back together.

That won't eliminate the cup or keep a flat board from cupping. But it will make a sine wave which is half or even a quarter the depth of cup.

 

[cpowell]

I am new to buying rough lumber and I bought some wide cherry boards from Gibsonville this weekend to make a writing table. They did not have a good selection of the regular 4-8" wide boards, so I ended up buying some of the 10"+ boards(and paying $2 per foot more). Well I get them home and cut a few pieces that I needed to get started and noticed they were warped. I cut them about 60 inches long and if you lay them on a flat surface, the center of the board is about 1/4"+ off the surface. Did I do a bad job of picking out my wood or is this pretty normal? Should I scrap these pieces and buy better boards?

Secondly, I was planning to make the top out of 4 to 5 six inches wide boards, but I bought a pretty nice 13" wide board. The top is 22" wide, so I could just rip the board down to 11" and join two boards to make the 22". Should I rip the boards down to 5.5 inches to keep them from cupping? It looks pretty good now and it has been in my basement workshop since saturday.
Thanks for your help!

Paying $2 a bd ft more for wide cherry (or other species) is a tough pill to swallow UNLESS you need the wider boards. Wall Lumber has had some OK cherry a few times I've been there. Seems nice cherry like to live just a bit North of NC.

You should be able to use the high price of cherry to justify a jointer purchase or may be a few handplanes.

It is not uncommon for planed stock to bow. If you can buy rough then you can crosscut to length and skin the outer surfaces and sticker it for a day or so in the shop to see if the stock will move. That will allow you to pick your plane line so you can joint to desired finished dimension. I won't buy 4/4 KD stock that is 1 inch or less for that reason.



Chuck

 

[Khb1526]

Thanks for every ones advise! I will work with what I have and make the best of it. I will post pics when I am done.