Wide or narrow boards for large oak glue up?

[scott vroom]

I'm getting ready to glue up a 12' long slab from 5/4 QSWO. The boards are flat and straight and are the following widths: 5", 6", 8", 9".

My gut tells me I should rip at least the 2 wider boards in half, leaving me with a 6 board glue up. Does anyone have any hands-on experience to know whether it's always better to glue up more narrow boards vs fewer wider boards? Am I less likely to get movement with more narrow boards? Final application is a desk top so each end of the slab will be secured to a heavy base cabinet at each end.

I seems the further I go with woodworking the less I know.

Thanks for any advice...

[Neil Brooks]

Yeah.

All things being equal, you're less likely to get warp/cupping with narrower boards, and alternating direction of your annular growth rings.

I think the QS will *minimize* the need for that, but -- since it won't *eliminate* it ... I'd probably minimize the risk, and rip some of the wider boards.

Good luck. Fun project ... and ... with beautiful stock

[Chip Lindley]

The thing about using narrow boards in a glue-up is being able to alternate the grain of each; smile, frown, smile, frown. But, with QS wood there is no smile/frown. Unless you flip half of each ripped board, it's trouble for nothing, and still may serve no purpose.

Providing stability beneath the slab by attaching it to the drawer banks to allow for expansion while holding flat, and a couple of battens beneath the slab in the knee space, hidden by the apron will go a long way to keep the slab flat once glued up.

[Steve Schoene]

I disagree. No advantage in ripping boards, especially quartersawn boards as narrow as 9". If you need to eliminate sapwood for esthetic reasons rip away, but if the boards will warp they will warp at 5" as at 9". Glue ups of lots of narrow boards just look cheap, in my opinion.

In particular I don't recommend alternating growth rings--following Tage Frid. If boards glued alternatively do cup, then you have a washboard. If the growth rings are all in the same direction, then the warp can pretty easily be tamed by the attachment on the ends to the heavy base cabinets.

[Prashun Patel]

I think you'll be fine as is. If it were me, I'd probably rip the two large boards just to end up with all boards roughly the same width, so if any seams were visible, they'd at least look uniform. Further, it's a little cheap added insurance to rip and flip. I do my big glue ups like this one board at a time. If you're gluing everything at once, then leaving the 2 large ones in tact apriori will lower the sweat-shimmy-bang-bang factor.

[John TenEyck]

I disagree. No advantage in ripping boards, especially quartersawn boards as narrow as 9". If you need to eliminate sapwood for esthetic reasons rip away, but if the boards will warp they will warp at 5" as at 9". Glue ups of lots of narrow boards just look cheap, in my opinion.

In particular I don't recommend alternating growth rings--following Tage Frid. If boards glued alternatively do cup, then you have a washboard. If the growth rings are all in the same direction, then the warp can pretty easily be tamed by the attachment on the ends to the heavy base cabinets.

+1 I agree. Even when I make a slab out of plain sawn wood, I match the boards for best appearance, first, and worry about which way the growth rings are pointing second. I have a unused slab in my basement made with 5 - 6" wide plain sawn red oak, which I oriented with alternating growth rings. It's a very nice washboard now - there would be no hope of flattening it except by planing the whole thing again.

[Scott T Smith]

Scott, if your material is quartersawn oak you should not need to worry about excessive wood movement (with the possible exception of any boards that have knots, crotchwood, feathered grain, etc. in them).

Inconsistent wood movement is usually related to the cellular orientation, exposure to moisture changes, or both. Quartersawn lumber has minimal inconsistent movement.

In support of that comment, attached are three photos. The first one is an edge photo of a pair of wide QSWO boards; you will note from viewing the edge that the board(s) behind it are flat. These started out as 5/4 boards, and have been S2S'd down to around 7/8".



side view.jpg

The second photo is a front shot of the same pair of QSWO boards from the first photo. The one on the left is 19" wide, the one on the right is 18". I S2S'd both of these boards about 7 months ago, and they have been exposed to the normal humidity changes that have occured in my shop over the fall, winter and spring. They have been standing up against a wall or in a rack ever since w/o any weight on them to "keep them flat". No cupping has been observed.


front view.jpg



18 inch QSWO.jpg

If 18" and 19" wide QSWO boards stay flat, I don't think that you need to worry.

Regards,

Scott

[Rod Sheridan]

Scott, I've made many table tops from QSWO, and use the boards as wide as they can be.

I really dislike the table tops I see that look like they're glued up out of 1 X 2's.

Regards, Rod.

[Chip Lindley]

...Even when I make a slab out of plain sawn wood, I match the boards for best appearance, first, and worry about which way the growth rings are pointing second. I have a unused slab in my basement made with 5 - 6" wide plain sawn red oak, which I oriented with alternating growth rings. It's a very nice washboard now - there would be no hope of flattening it except by planing the whole thing again.

Isn't that why they make wide-belt or wide-drum sanders? Any slab I glue up will be over-thickness to allow for final finishing.

If all boards were oriented with growth rings in the same direction, you would have a very pronounced cup in the whole panel now. How would you propose to flatten that one?

[scott vroom]

OK, wide boards it is! Here's pics of the lumber going through the planer and jointer....using the room adjacent to the shop for the outfeed. The roller stands worked great.

The final project will be 25.5" wide so we ended up ripping an inch or so of sapwood off the edges of 2 boards.

Next is the glue up....proabably on the tile kitchen floor. We're going to do two 2-board glue ups, run each through the planer then do a final single seam glue up.

We're going to end up with a 1" slab.....any thoughts on how to treat the desk front edge? I was thinking about a double roundover (but not a full bullnose). Maybe running a 1/2" roundover on the top and bottom edges? Appreciate any inputs and ideas....thx!

[Jim Becker]

I'm one of those folks that will never rip a nice wide board for gluing up a panel. The movement across the width will be the same and how you incorporate the panel into a project will insure that it stays flat. I also don't do the "alternating growth rings" thing, either...best face always goes on top. I will take great pains with grain and color matching so that any glue joints I do have will disappear or nearly disappear if at all possible. In my ideal world, a panel would be from one board with no glue joint...

[John TenEyck]

Isn't that why they make wide-belt or wide-drum sanders? Any slab I glue up will be over-thickness to allow for final finishing.

If all boards were oriented with growth rings in the same direction, you would have a very pronounced cup in the whole panel now. How would you propose to flatten that one?

The slab I referenced was drum sanded flat after glue-up but now, months later, it is a washboard. If I had attached that slab when it was flat to a table it would still be a washboard today. If I had attached a slab made from boards with the growth rings all in the same direction, it might have cupped a little in one direction or the other, but it would be hard to notice compared to how a washboard one looks and feels. If I had left it in the shop as a slab it probably would have a great big curl in it now. But the point is to attach it to your project while it's flat, and it will stay flat.

[Kent A Bathurst]

........We're going to end up with a 1" slab.....any thoughts on how to treat the desk front edge? I was thinking about a double roundover (but not a full bullnose). Maybe running a 1/2" roundover on the top and bottom edges?

I round-over the edges of some stuff, but 1/2" would be a bit too extreme for me, even for something on the scale of what you are making. I'd prolly hang out in the 1/4" - 5/16" range. If I might make a suggestion - start with something smaller, like one of those. See what you think. You can always increase the radius with a subsequent pass if you don't like it.

[Rod Sheridan]

Scott, in my opinion, I wouldn't use a round over on that desk top.

I would put a shallow bevel on the underside and just break the top edge with a gentle sanding.

Regards, Rod.

[Steve Griffin]

I'm one of those folks that will never rip a nice wide board for gluing up a panel. The movement across the width will be the same and how you incorporate the panel into a project will insure that it stays flat. I also don't do the "alternating growth rings" thing, either...best face always goes on top. I will take great pains with grain and color matching so that any glue joints I do have will disappear or nearly disappear if at all possible. In my ideal world, a panel would be from one board with no glue joint...

Yep. Last time I glued up a 26" wide x 11' dresser top out of oak I used 2 boards!

Scott--Since we're throwing out roundover opinions, I'd just ease the bottom edge and use 1/4" round on top. A large roundover on the bottom only makes your top look thinner.

-Steve