Gluing Question

[Bruce Ferm]

I have a bunch of 3/4” x 1” x 4” pieces of wood that I need to laminate into a board. I have to glue the 3/4” sides together so that I produce a 4” wide, 3/4” thick, 15” long board with the grain running across the 4” width instead of along the length. The pieces are Maple, Cherry and Black Walnut and they’ll be alternated to produce a striped board. The finished board will be used in a decorative application and won't bear any significant weight. I plan on gluing it together simply---one joint at a time, using Titebond glue and regular small bar clamps. I wasn’t planning on using biscuits because of the small scale of the project and I’d like to come up with a finished board that isn't badly cupped.

If anybody has any advice or experience with doing this kind of thing, I’d appreciate any input I can get. Thanks for your help.

[Roy Harding]

If I read you right, you're planning to glue end grain to end grain? If so, I'd be looking at either a mechanical joint, like a sliding dovetail say, or a tongue and groove, or scarf joints, or overlapping rabbets so that you've got some face grain to face grain surfaces. Or even overlapping rabbets with dowels piercing the joint, or butterflies - the possibilities are endless. Point being, you can't just glue end grain to end grain.

[Paul Hinds]

If I understand you right, it's the opposite understanding of what Roy got, you are only gluing side grain to side grain and plain old yellow glue should be just fine for that given that it's not going to bear any load. Even yellow glue these days tends to give a joint that is stronger than the surrounding wood. But Roy is absolutely right that if you are doing end grain to end grain glue is not enough.

[Jerry Miner]

If I understand you, you are gluing 1" wide pieces together--side-to-side--to make a 15" wide, three color strip. Just glue and clamps will do it.

But one-at-a time is both slow and prone to getting out of flat. I would glue it all in one shot, with a set of cauls of some kind to keep it all flat and co-planar--even if it's just a couple pieces of plywood with some wax to keep from gluing the project to the cauls.

[Jerry Miner]

You want something like this, right?


three-color board (11-24-14).jpg

[keith micinski]

I disagree completely about gluing one at a time causing a flatness issue. I have found by far and away when I need something flat and even the best way to do it is one at a time so you are only trying to line to edges up instead of twenty. Of course I don't do this very often because I can usually just run the piece through my belt sander to flatten them out

[Kevin Jenness]

One at a time is a waste of time. One clamp and two pairs of waxed cauls will do it and just fit within the 4" width. The cupping will come later.

[Bob Carreiro]

Glue is enuff, but putting cauls on something so narrow may prove difficult.
If it were me, I'd glue one at a time followed by shooting two 18g X 1-1/4" brads into it. This way, you can pretty much INSURE they'll be even, and all the glue can be washed off before it sets. After gluing/nailing the first pair, glue & nail the third peice, and so on. If you don't want the small nail holes showing on the (last) end peice, just glue & clamp it.
That's my 2 cents.

[Kevin Jenness]

Here is how I would do it. Why is another question. Cut two 3/4"x2" end cauls. Set two 3/4"x2" waxed straight cauls up on blocks high enough to get sliding c-clamp tips under them, 2 1/2"" apart. Lay one end caul on the waxed cauls. Run a bead of glue on the edges of the strips and put them in place one by one, finishing with an end caul. Put another pair of waxed 3/4"x2" cauls on top of the assembly and snug them up lightly with three clamps along their lengths. Now clamp the assembly end to end with a bar or pipe clamp from above. Hold the bar clamp above the glue lines to prevent staining. Tighten up the cauls before putting final pressure on the bar clamp. Unclamp and clean up the glue while it is still slightly rubbery on the surface.

The assembly will probably cup as the moisture content changes unless restrained by some kind of framework or battens. You may minimize cupping by alternating growth ring direction.

What are you making?

[Prashun Patel]

"You may minimize cupping by alternating growth ring direction."

I agree with Kevin. Alternate the growth rings - especially for pieces coming from the same wood. This will not only reduce post-glue-up cupping, but will also serve to correct any tiny imperfections in how the boards are jointed.

[keith micinski]

It will only cure imperfections in jointing if the board that is placed adjacent to is imperfect in the exact opposite direction. Other wise it will magnify it. The cupping of growth rings all the same way may or may not be true. I think it's one of those things that makes sense in theory but probably in practice is overkill. Also. Kind of like using regain preventively, how can you be sure you were going to go bald if you hadn't used it. If everything is milled and dried properly then your best bet is to use the boards grain to decide orientation.

[Prashun Patel]

keith is rigt about the jointing. You have to joint all pieces off the same reference face but when you flip the growth rings, you also have to rotate the piece 180 degrees so the grain is running in opposite directions for the jointing statement i made below to be true.

[Bruce Ferm]

1---This is gluing piece sides to each other. No end grain gluing involved.
2---Jerry Miner... Yes. Your diagram is exactly what I’ll be trying to produce.
3---Thanks to everybody for your inputs. I think I’ll used waxed guides, probably use brads and work the finished pieced over with a belt sander as well. If that doesn’t end me up with a reasonably decent-looking finished board, it’ll probably be a good time for me to take up knitting.

[Jim Matthews]

I disagree completely about gluing one at a time causing a flatness issue. I have found by far and away when I need something flat and even the best way to do it is one at a time so you are only trying to line to edges up instead of twenty. Of course I don't do this very often because I can usually just run the piece through my belt sander to flatten them out

+1 on this.
That many edges, all small piece at once?

I think there's a board game based on that...

This job cries out for saran wrap, plywood cauls and a set of wedges to drive everything together.

[Jim Matthews]

If you can use a handplane, or get a hand plane into a vise,
you can "shoot" the edges square (or very close) by hand.

http://www.handplane.com/60/hand-planing-small-items/

While I would suggest gluing up in smaller stages, it may be
possible to do this with a set of larger plywood "cauls" - from 3/4" stock.

Get the plywood base caul stable on a flat surface.
Screw it down, if you want to be sure.

Lay over that a sheet of saran wrap or wax paper.
Arrange your pieces along the board as you want
them to be glued.

Fix a "batten of the same or lesser thickness to one end.
The first piece will be pressed against that batten,
make sure the batten can't move.

If you're making more than one of these, glue the batten down.
Make sure the saran wrap or wax paper separates the batten
from the array of strips.

Alternately, apply wax to the batten so glue won't stick.

Prepare a set of sliding wedges, thinner than the stock.
One will be fixed to the base board - either with glue or screws.

Glue up the array - use something with a long open time.
I like hide glue, but if this is for a kitchen - something more water resistant, maybe.

When the array is assembled - lay down a top layer of saran wrap or wax paper.

Apply weight or clamps.

Drive in the "free" sliding wedge until you see squeeze out.

Leave the works alone, overnight.


Clamping lots of small pieces at once.jpg