Edge jointing/panel glue up ?

[Mark Stutz]

Although I used to think that powered edge jointing produced good results , since using hand planes the diference is astounding. I recently have been gluing up some cherry panels for use in my current project. On a couple of them I used the "both boards together face to face" technique, and on others, jointed each board square. Took a little longer but, but I persevered.

My question has to do with glueing the panels. The ones using the "two boards together" technique resulted in a tight joint, but the end result was a not very flat panel, and I ended up losing a bit over a sixteenth in thickness. They were still above my nominal thickness so it didn't matter except for making a lot more work. The panels that had each board jointed individually came out almost perfect. Only minimal scraper work.

I'm wondering if the first technique results in a slightly angled joint that creeps a bit after the clamps are in place. This wouldn't happen of the joint is perfectly square. Has anyone else observed this phenomenon? Did my technique for glueing just get better. Obviously this could be compensated for with clamping cauls, but why do extra work if it's not needed? Do you guys regularly use cauls? Anything I am missing?

Thanks.

Mark

[Mike Henderson]

I almost always use cauls when gluing up a panel, no matter how I do the jointing. Depending upon the size of the panel, I'll use two sets of cauls, or three sets on a big panel. It's just good insurance (and good practice).

Mike

[Pam Niedermayer]

Like Mike, I always use cauls for panel glueup, and even then may get a tiny step across the joint, not 1/16" though, much smaller. How did you glue the joints? Did you use biscuits or dowels or simply rub the boards together until they were mated?

I think it's likely that you could get a slight tilt that could have slipped. Clearly that "shouldn't" matter. After all, when you scarf join two boards you'd have a much longer/wider intended tilt that has to be accommodated during glue up.

Pam

[Mark Stutz]

Thanks Pam and Mike.

The worst one slipped so that there was about a 1/32 step. With my skill level I lost almost 1//16 by the time I got everything back to flat! I actually tried using buscuits on one, but it didn't seem to matter much. My best results were with the simplest procedure. Hmmm, guess that alone should tell me something.

Do you have dedicated permanent cauls? Do you crown them slightly? Or do you just go thru the scrap bin looking for appropriate pieces whenever you do a glue up?

Thanks for your help.

Mark

[Pam Niedermayer]

Reading your question, Mark, I realized that I was a bit careless with the "cauls" word for panel glue up, because they're not really cauls, exactly. What I use are these Veritas panel clamps http://www.leevalley.com/wood/page.a...838,47843&ap=1

I made the clamps with a slight crown, very slight. For other glue ups, I do use cauls, a mixture of custom for a specific project and scrap. But now I'm thinking that using real cauls for panel glue ups might be useful, perhaps run some on top of the actual joint, with a wax paper separation of course.

Pam

[Mike Henderson]

I use real cauls when I do a glue up. I got some klin dried construction 2x4's from the borg. I cut them into about 36" lengths (also have some 48") and jointed them on the jointer. Then put wide Scotch tape (packing tape) on them to keep glue from sticking to them.

To use, lay out some spacers, then put the bottom cauls on the spacers. The reason for the spacers is so that you can get a clamp on the cauls. Next, lay out the boards to be glued (with glue on them) on top of the cauls (crossways to the cauls - the cauls are 90* to the boards to be glued). Now, put the top cauls on in line with the bottom cauls and clamp the cauls tight to align the boards.

Finally, put clamps on the boards to pull them tight. If you need room, you can take the cauls off in about 15 minutes - the glue will have set enough that the boards aren't going to move any more.

Anyway, that's how I do it.

Mike

[Mark Stutz]

Pam, Mike,....Thanks.

Mark

[Robert Trotter]

When you use cauls do they have to be near to the width of panel being glued up? Or can you use say a 36" caul over a 18" panel (just an example )? I can't see why long cauls over a short panel wouldn't work but people with experience might know differently.


Also the same as things like bow clamps???


Robert

[Ron Brese]

Mark I suspect that you did indeed have surfaces that even though they complimented one another, were at a slight angle. Next time an adjustment of the plane iron will probably aleviate this bit of bother. Cauls are a good tool just be careful that the use of them does not leave the joint slightly open on one side. I would rather have to do a bit of work later to flatten and know I have a good glue joint than to have a flat panel with a joint that has only about 60 to 70 percent good contact on the glue surfaces.

Ron

[Mike Henderson]

When you use cauls do they have to be near to the width of panel being glued up? Or can you use say a 36" caul over a 18" panel (just an example )? I can't see why long cauls over a short panel wouldn't work but people with experience might know differently.


Also the same as things like bow clamps???


Robert

You can certainly use cauls longer than the width of your panel - it's just a bit inconvenient, somewhat like using very long clamps on a short panel. No matter what length you use, when you clamp the cauls, your clamp should go on the cauls over the wood of the panel - just for convenience - it's very difficult to clamp the cauls "off the panel".

You can also use cauls that are shorter than the width of your panel, as long as the cauls cover all the joints and you can get a clamp on each end of them. But it's better and easier if their length is about the width of the panel.

One of these days I'm going to make a special place to store my cauls, but for now, I store them between the wall and my bandsaw.

Mike

[Roy Wall]

Good info Guys!!

Thanks.......

[Robert Trotter]

Thanks Mike for the info.

I don't have many clamps at the moment and have been thinking about cauls and maybe something like bow clamps for glue ups to save some money on clamps. parallel clamps are very expensive here in Japan.


An added question about edge jointing and clamp ups....If I had a twin screw vice and used rows of dogs on the vice and on the bench, is it possible to get good glue ups of panels? Are there any problems with this method?
Could you then just put one caul over the top (at each end) and clamp it to the bench?

Roy, sorry if I am hijacking your thread. You have a very good question that I have been interested in myself.

When you glued the face-to-face jointed boards did you possibly have fliped one when gluing? Otherwise I am like you and can't see why it would not have worked.


Robert