Glue joint cutter

[Susumu Mori]

To make a wide panel, I recently start to use Domino, which I prefer to traditional glue joints. It is less fussy AFTER glue is applied but the domino-ing BEFORE the glue application is an extra step. Usually I want to add dominos at the edges of the boards but I need to be careful and well planned because if I put them too close to the edge, they could be revealed after the final dimensioning of the board :eek: I must admit that "careful planning" is not my forte...

Anyway, my question is, how do you think about glue-joint cutters? I saw some Youtube videos from Europe and it seems popular there, but I don't think it is common in US. If you have any experience in it, what are the pros and cons?

[Art Mann]

I have tried both dowels and a glue joint cutter for wide glue-ups like a table top. I prefer dowels (or in your case Dominos). It is difficult to route the matching profiles in such a way that they yield a perfectly flat surface from one end to the other. You need very flat and uniformly thick stock. I use a Dowelmax doweling jig. It has a feature that allows you to locate the dowels at an exact spacing without careful measurements. I'm not sure if the Domino is capable of doing that but I would still prefer it over the routed edges.

[pat warner]

They're (the cutters) great if ground well and your thicknesses are in its range.
Can joint & profile in a single step, aligns your sticks,
adds ~ 40% more glue line.
And will resist impact much better than a butt joint.

[Mike Cutler]

A lot would depend on the finished aesthetic. If the butt ends were hidden, a glue line bit would be great, but if the butt edge of the project is going to be exposed, having that glue line profile might look a little "cheesey".
I personally use a tongue and groove joint when I edge glue two boards. Many people just butt them up against each other with no additional steps. For a guy working alone though, it's a great aid to have those boards align themselves somehow. Especially if the piece is big.

[Mike Henderson]

The other approach is to use cauls in your glue-up to make sure the boards are aligned. When you do a glue-up with cauls, you only need to leave the cauls on until you get the boards in clamp (tight). So you can clamp up your boards, and five minutes later take the cauls off and you only have to deal with the panel and the clamps. If it's small enough, you can set it against the wall, or if it's big, you will probably need another person to help you pick up up and set it against the wall.

Of course, if you have lots of room in your shop, or if you're not going to do anything else for the next hour or so, just leave everything there in clamps.

With cauls, you never have to worry about cutting through a biscuit, domino, or dowel.

Mike

[Art Mann]

They're (the cutters) great if ground well and your thicknesses are in its range.
Can joint & profile in a single step, aligns your sticks,
adds ~ 40% more glue line.
And will resist impact much better than a butt joint.

I have done destructive testing on glue-ups of this sort many, many times. The result is always the same. The wood never breaks at the glue line. It always splits somewhere else. 40% more glue line isn't very important if the joint won't break even without one. The only purpose I can see to using any kind of reinforcement between the boards is for alignment sake.

[Susumu Mori]

Hi Mike,

I always wonder if cauls spread glue and mess up the boards?

[Mike Henderson]

Hi Mike,

I always wonder if cauls spread glue and mess up the boards?
I suppose they could but I've never had any problems with using them. I remove the cauls before the glue sets and since I use PVA, I scrape and wash the excess glue off.

Plus, you're probably going to sand the panel and that will also remove any excess glue.

Mike

[Mike Schuch]

A lot would depend on the finished aesthetic. If the butt ends were hidden, a glue line bit would be great, but if the butt edge of the project is going to be exposed, having that glue line profile might look a little "cheesey".
I personally use a tongue and groove joint when I edge glue two boards. Many people just butt them up against each other with no additional steps. For a guy working alone though, it's a great aid to have those boards align themselves somehow. Especially if the piece is big.

I agree, the zigzag profile on an exposed end would not do it for me. I prefer dowels. A horizontal boring machine makes pretty quick work of the dowel holes.

You don't need to worry about putting them too close to the edge... you only do that once and it burns into your memory pretty well!

[Mike Cutler]

Mike

Yeah, it looks too "manufactured" for me when the glue joint is exposed if a glue line bit is used. A full length T&G joint can look "period authentic" in some instances, but it's not always the right joint either.

If I use biscuits, or floating tenons cut with a router, to align pieces I always lay out the pieces as they will be glued and draw the cut lines. That way I know where any "alignment aid" will go. Even with cauls it makes it a little easier. A trick I was taught many years ago was to cut a groove in the ends and put a tight fitting spline piece in to bring the end into alignment. You have to leave an inch or two excess length, because the groove/spline will be cut out. ( This was before the widespread use of biscuit joiners )

[Michelle Rich]

I have made furniture for over 25 yrs..I stopped using all the" alignment " helpers many years ago. A caul, a well placed rubber hammer whack, works ok for me.

[Rod Sheridan]

Hi Susumu, I have used glue joint cutters in my shaper and they work very well, however there is no need for any dowel, biscuit, spline, glue joint profile etc. when gluing up assemblies.

Glue joint cutters are great if you're using unskilled labour to glue assemblies, however the conventional method of hand gluing without alignment methods produces joints that perfect with very little work.

A tap from your hand will align the pieces well enough that all that's required afterwards is a card scraper to level the panel.

I would avoid any mechanical alignment method............Regards, Rod.

[Jerry Thompson]

I have used Mike H.'s cauls that he shows how to make on his site. I have never looked back since. They do the job and are inexpensive to make.

[Mike Henderson]

I have made furniture for over 25 yrs..I stopped using all the" alignment " helpers many years ago. A caul, a well placed rubber hammer whack, works ok for me.
I agree with Michelle but I use a plastic head hammer. I found that rubber hammers often left black marks on the wood.

Mike

[Susumu Mori]

Thanks all,

Yes, I agree that the board ends do not look attractive with the cutter patterns. It is interesting that some exposed joinery, like dovetails makes the furniture look better while some doesn't look good.

Also, I learned that many experience woodworkers end up with the traditional edge jointing. Maybe I should try cauls too.

One nice thing about Domino is, I only need one good surface and I can leave some imperfection in the other side. After finishing one face with a jointer, I can dimension the thickness by a bandsaw, which, unlike planers, doesn't care how much material I need to remove and I'm ready after one pass through a jointer if bandsaw marks bother me. The middle sections of the boards could be thinner if it doesn't show at the edge of the glued board. I'm not sure how cauls would work in this situation. Maybe I'm too lazy, not using a planer for perfect thicknessing.....

[Joe Jensen]

As others have said, you do not need more than a straight flat edge to join boards edge to edge. If you don't have flat boards and you don't have a very straight edge then you need something to align them. Before I was able to get really flat edges and before I could thickness my own boards I tried a ton of "alignment" techniques like dowels and glue joint cutters, etc. All take a lot of time. In the end getting your stock flat and true before glue up is quicker with better results. But doing this requires a jointer and a planer (thicknesser).

I buy all my wood rough sawn so I can cut pieces slightly oversize so I can get to flat stock to build with.
1) Cut pieces a bit oversize
2) make one face surface flat with the jointer
3) Thickness with the planer to get both faces flat and parallel
4) Use jointer to make one edge perfectly 90 to the faces and flat
5) Rip board to width
6) Trim one end square
7) Crosscut to length.

Doing this makes glue ups a breeze and at least for me it's way faster than fussing with my domino of glue joint cutters.