Gluing-Finger Joint bits verses Biscuits or ?

[Phil Winn]

For gluing up (solid) boards for table tops, or cabinet sides etc, I have been jointing them, applying glue to both sides, and then clamping them together. I was talking to a younger “trained” woodworker who said that if I either used a Finger Joint Router Bit, or a Biscuit Jointer and obviously glue. Are there any other methods? In your opinion what is the best method? Since I am doing this for a hobby, speed is toward the bottom of the list.
Strength, ease of use, low potential for “messing-up”, are toward the top. With your preferred method, any specific Makes and Models ie. Whitehead model #? or DeWalt model #?. Since these are not major purchases, price is not the biggest concern either.
Thanks again,
Phil

[Jamie Buxton]

There are almost as many ways to glue up a panel as there are woodworkers. Here's my take...

I use simple butt joints. I use a jointer and planer to make all the boards straight, flat, and true, before I attempt to glue them into a panel; IMHO that's the key. I glue the boards one at a time, rather than trying to glue up a whole panel at once. I arrange my lighting so that it glances right along the face of the boards. Misalignment is obvious from the shadows. I get two boards glued up, wait a half hour or so, and add the next board. I generally get good enough alignment that a cabinet scraper levels the lippage.

I don't use biscuits. They don't add any appreciable strength to a nice long butt joint, and they're an extra step.

The finger joints which your young friend suggested are useful only at the ends of boards. They're a way of joining boards end-to-end. For side-to-side joining, finger joints eat way too much lumber, and the butt joint is already strong enough with the finger jointing.

For lots more discussions on this topic, use SMC's Search function. It is quite good.

[Mike Henderson]

What your friend is calling a finger joint is probably a variation on a tongue and groove type joint. In any case, the main value of that kind of joint, or of biscuits, is to align the boards while you clamp them. A standard, well fitting butt joint is plenty strong enough.

For gluing reasonably sized panels, look into using cauls. These are boards that you have jointed straight, that are long enough to go across the panel. Apply cellophane tape to them to keep them from getting glued to the panels by the glue squeeze out.

When doing a clamp-up, put the glue on the boards, and put them together. Next take four cauls, two on the top and two on the bottom. Clamp two cauls together with the panel boards between them. Do the other two cauls. Now add the clamps to clamp the panel together.

The cauls will keep the boards straight as they are clamped and the glue sets.

Mike

[Curt Harms]

Hi Phil

Glues with fast tack that can be removed from clamps in 15 minutes is helpful to the professional e.g. Titebond. Fast tack may not be an attribute to You & I. There are glues with longer open time, e.g. Titebond extend, Polyurethane glue, liquid hide glue or my new curiosity, Roo Glue. These give 10 minutes time or more to fuss with alignment before the boards can't be moved without jeopardizing the joint. It's longer before the parts can be removed from the clamps, but I need that time to admire my handiwork and plan my next step anyway:)

HTH

Curt

[Steve Clardy]

Simple butt joint is the easy, best joint.
Biscuits are useful for alignment, doesn't add much in strength, more glue area.

[Allen Bookout]

Has anyone tried the reverse glue joint router bits? I have not but it seems to me that it would be faster to spend a couple of minutes to run each board down a bit on a router table than to mess with cauls and such, that is if they work anyway.

Advertised to increase glue area also but that does not appear to be a problem anyway.

Allen

[glenn bradley]

I forget the magazine but, the question was similar in regards to strength of glues. Two pieces of oak were jointed and butt glued with Titebond II (not an advertisement, its just what was handy). The boards were clamped for 30 minutes, unclamped and allowed to dry for 24 hours. The joint was then stressed to the point of failure. . . one of the the boards cracked, the joint was undamaged. I don't remember the mag but I'll never forget the picture of the broken board.

[Rodney ORourke]

I use a variatoin of this to produce a panel effect sometimes.

The interlocking groove bits have to be stronger by way of more surface area with the grain. I agree it is overkill and more work for nothing unless you are looking for some visual impact on the board ends. Jointer 2 adjacent side on work peice and then to the planer pior to gluing is essential to getting a good glue job. Often over-looked are the boards themselves. Look for boards that have the grain running 90 degree to the top of board and parallel to the side of the board.

I learned the hard way to not get in a hurry because bad things can go by easily on alignment when checking too many glue surfaces at the same time. A lot can go arong when clamping the boards even in a good jig that can remain un-noticed until after the glue sets. So the advice you got above to glue only 2 items in each step of the process and to use reflective lighting is wise.

Using biscuits in table tops is begging for trouble. May work fine for Brazilian Cherry that is about two steps off of becoming a rock; but can easily go wrong - all of us have probably sat at a table that had a subtle but noticeable wave pattern that follows the glue edge of the two joining boards. That is a biscuit system swelling - sand it and later in the year you will see a valley where the mountains were before. Biscuits are strong and easy - but use them if there is no time for a tenon and mortise, Just gppd to avoid on a table top where the reflecting light can easily show height variations on a table top

Good Luck :)

[Mike Cutler]

Phil.

I use tongue and groove joints for almost all the large panel glue-ups I have done. If grain matching, ie. bookmatching is important than a spline that runs the length is used.
I realize that it is overkill, and that a simple butt joint would more than do, but it's just the way I was taught.
I'm not a big fan of biscuits in furniture. They definitely have their application, but table top, or large panel assembly is not where I would use them.

I have taken to using epoxy for glueups lately. I don't think that I've used titebond in over a year now. The ability to control the open time is a great advantage for me, since I work alone.

[Phil Winn]

Good to learn that the time test method-jointing-gluing-clamping still works well especially with the newer better glues. I never thought that biscuits would swell with changes in humidity... and under special conditions perhaps finger jointer bits could make some sense. Now I can save the $ for a M & T machine-either power tool or more chisels!
Thanks,
Phil