Width of Boards for large solid glue-up?

I am making the top for a TV cabinet (Mission Style) and it will be

25"x42"x1" - I have a good supply of 5/4 red oak and am wondering if it would be wise to glue up 4" strips to make the top or just go with 3 - 8" pieces? The wood is flatsawn and not quartersawn.

Any advise or comments appreciated. . .

BillyB

Reply to
BillyBob
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I don't want to be a smart ass but last time I checked, 3*8 doesn't quite get you to 25.

No matter how you approach it, 4 boards are req'd to make a 25 wide top.

How you cut them to get there depends on the wood at hand. You have to make that call.

Lew

Reply to
Lew Hodgett

It's not absolute dimension or ring orientation that counts, so make it look good. If that involves a four inch between two eights for a nice grain pattern, have at it. I think a lot of folks neglect the mock up and mineral spirit stage and end up with some ugly, but reversed ring glueups.

Reply to
George

The limiting factor on the width of the boards making up your panel should be the width of your jointer. If you have an 8" jointer, by all means use 8" boards -- but you won't get a 25" wide panel out of *three* eight-inch boards.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Reply to
Doug Miller

Within reason the grain pattern that "I like" determines the width of each board...

BUT to be honest I "cheat" a little (alot) to get the look I want... a 25 x 42 top may end up a little larger or smaller...

In General I find myself using boards between 4 and 5 inches in width...( Joiner is only a 6 in one anyway... )

Bob Griffiths

Reply to
Bob G.

Somewhere I read 3 inches as best (where? I don't remember) and that if your ripping them and cutting you turn over every other piece then glue 'em up! top-bottom-top-bottom....

joe

Reply to
My M-14

Thanks all for the ideas - I do realize that 8X3 = 24 and not 25 but the boards are about 8.5" each.

My main concern is the stability of the top to keep it from warping or cupping. I will alternate the board grain directions for sure.

Has anyone actually used 8"+ boards for such a glue-up and how did it work?

Thanks BillyB

Reply to
BillyBob

My largest glue-up has been approximately 76" x 40". I've used boards up to approximately 10" wide in glue-ups with no problems. I, like others have mentioned, do glue-ups that give me the grain pattern I like, regardless of which face ends up on top.

Remember, start with wood that is acclimated to your shop. I like to mill my wood to slightly thicker (1/8" or so) than finished size. I then sticker and let sit a day or two. That will typically give any problem boards time to move; these I re-joint. I then plane all to a hair thicker than final size and then glue them up. The glue up is kept stickered after it is removed from clamps until it is in the final piece.

david

ps. Since your design is for a tv cabinet, I take it the top will be attached to the rest of the cabinet. This will help keep it flat.

Reply to
David E. Penner

"BillyBob" wrote in news:gduee.11394$Ri.1496@trnddc08:

I take a different approach.

My thickness planer is 13" wide. So I set up for a nice grain pattern, with as much rift sawn grain as feasible (visual preference of mine for red oak), and glue up to about 12" wide, twice, and then thickness the stock sorta close to final thickness. Then glue the two pieces together, using clamping cauls, and level the resulting glueup with scrapers and/or power sander.

2* (8.5") doesn't go through my machinery, so I change my methods.

Attaching a solid top so it won't warp, but still moves as it must, is a topic for another thread.

Patriarch

Reply to
Patriarch

The conventional wisdom that 4" will prevent cupping is most likely based on 4/4 thickness.

This would scale as 2" for 2/4, 5" for 5/4 etc.

8" for 4/4 is pretty risky; especially if there's a temperature difference expected through the thickness as in the case of a TV cabinet.

Dave

Reply to
dmartin

I think you need to read some wood technology.

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is a good place to start.

Reply to
George

On Thu, 05 May 2005 19:11:08 GMT, the inscrutable "BillyBob" spake:

My favorite quote from Frank Klausz is "Yes, alternate growth patterns. That gives you a nice ripple effect when it warps."

He likes wide boards and puts the growth all the same direction but with the best face up/out. No matter what width you use, make sure to use the same amount of finish on both sides of the board to equalize the moisture changes.

Reply to
Larry Jaques

According to a recent article in Popular Woodworking (by Flexner, I think), this makes *no* difference at all to whether the tabletop will eventually warp or not.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Reply to
Doug Miller

Wood warps. Wood moves. How much depends on how your top is attached to the other box members.

-- dadiOH ____________________________

dadiOH's dandies v3.06... ...a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at

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Reply to
dadiOH

When I was working up the courage and gathering knowledge for my first DiY cement pour (patio - the forerunner of the modern deck), I found an amazing consensus among contractors. They said "sometimes cement cracks, sometimes it doesn't."

Seems there are ways to guarantee failure, but none to guarantee success.

26 years later - no cracks. Saw it three years ago when visiting.
Reply to
George

I attended a woodworking show a while back and watched a presentation by Kelly Mehler on wood selection. When the topic of glued-up panels, such as tabel tops, came up, his opinion is that you choose your layout based on what looks best. He said that if you glued up a table top and then just laid it against a wall, well you might get some warping. But things like table tops are constrained against movement by virtue of them being attached to a base, which keeps them from warping.

todd

Reply to
Todd Fatheree

George, I read the chapter on drying and dimensional change in the reference you pointed to. I found nothing inconsistent with what I said.

My family has been in the millwork/commercial cabinet business for 50 years; we used a 4" maximum as a rule of thumb for a glued up top with alternating orientation to limit the total amount of washboard like cupping.

One source of cupping is a result of imposing a differential moisture gradient across an originally flat, uniformly dry board. This can be caused by a temperature drop across the wood (a temperature difference results in a relative humidity difference that in turn results in a moisture content difference.)

Another common cause is running boards that have a moisture gradient through the planner; they'll cup after the gradient goes away.

Anyhow, if the root cause for cupping deformation is a change in dryness gradient thru the thickness of the board, the resultant curvature will involve the moisture difference times the expansion coefficient divided by the thickness of the board.

A 4" wide x 1/8" thick board moist on one side and dry on the other cups a lot more than 4" wide x 1" thick board under the same swelling conditions (the cup depth of the thin board will be about 8 times that of the thicker board.)

Using the dimensional strategy I mentioned in my previous message (glue-up board width proportional to thickness) keeps the relative washboard effect the same after equilibriation.

Do you have evidence to the contrary? Or perhaps you thought I was refering to thermal expansion due to my mentioning temperature gradients?

or maybe we were wrong all along?

Dave

Reply to
dmartin

Then you should look and see that each board acts independent of the others, so it makes NO difference whether they're up/down wide or narrow, what makes the difference is where they came from in the log.

My family built cars. How nice for yours to work with wood.

Reply to
George

I'd keep your widest boards wide and fit the smaller ones in as they look best on the show face of the glueup.

You will find guys that will tell you to flip the grain orientation but I wouldn't pay them much mind.

There are co-equal evils in keeping the wood bark side up and down - as well as flipping them in pieces that are three or four inches wide.

I'd go for the best look and depend on the joinery and bracing to take care of the inevitable instability.

Tom Watson - WoodDorker tjwatson1ATcomcastDOTnet (email)

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(website)

Reply to
Tom Watson

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