|Project by C_PLUS_Woodworker||posted 04-28-2014 09:28 PM||16571 views||141 times favorited||33 comments|
Most of my glue-ups have been cutting or cheese boards or one board glued to another for a “wider” board.
From this site, years ago, I first learned about cauls and have used them effectively for a long time.
I had been using a bunch of different lengths of 4/4 or 8/4 oak covered with shipping tape, but got tired of messing with clamps on both ends. Two person job. The best way I found to “install” those cauls was to put a rubber band around one end of the set of cauls, then hustle and put another rubber band around the other ends, and then start clamping the caul ends on each side. X 3 or 4 cauls……..it was a little bit of a hassle…but worked.
Also, these little 2×2 x ?? cauls would bow in the middle when clamping pressure was applied.
I am now doing a big (for me) piece….... a craftsman style Cherry entry or sofa table…….(not traditional oak, she wants Cherry). It has a 19×50 top and one slightly smaller shelf.
I wanted better cauls. And hopefully, only one person would be required to use them.
Researching and reading-up on cauls was also a very good primer in table-top or panel joinery. Learned a tremendous amount. Pretty much took my nervousness away. I realized I had the equipment and accuracy and the skills to do these panel glue-ups…....and that I need not be as concerned as I was.
Even after 4 years here, I am still very much learning stuff, so I thought I would share a LITTLE of what I learned.
Lots of info about slightly curved cauls designed to apply equal pressure across the glue-up. Almost went that way, but still a two-person job…......for a few minutes.
One of the “rules” I read said “no gaps should be present with just hand pressure holding the boards together”.
None of this 1/8th inch or 1/4 inch gap stuff.
I learned, as it was mentioned often, board edges are ready to be joined according to the rule of “just hand pressure”….when hand pressure showed no…......NO …..gaps
That was my goal and I achieved it.
Putting the cauls on first while holding the boards together greatly reduced the amount of side clamping pressure needed. The cauls should (and did) hold the boards in place while I tightened down the alternating pipe clamps……… both processes letting the glue do its job. No breaking down a line of “setting” glue by tightening or loosening or messing with the clamp pressure over and over to get a tight glue line.
The table plans called for making the top and the shelf last. SCREW THAT ! That was the toughest part for me, so I did them first.
And, I wanted “good” or better cauls.
THESE WORK !!
I am a little surprised to end up making and using cauls with such easy plans at such an easy site to find using such common material. I had expected to be making some “exotic” cauls, but the more I read, the more these cauls made sense……………at least for me.
The caul plans call for hardwood, but I did think that excessive. Used 1×4 clear Poplar. NO WAY 4 strips of 1×4 Poplar PER CAUL SET are going to bend when clamped “edge to edge”.
And the cauls worked flawlessly.
Middle Cherry board had a very small …....about a ¼ inch bow over the entire 50 inches.
Carriage bolts are called for because they are threaded the entire stem, enabling use on any thickness of project.
The carriage bolts slide in or out so that pressure is applied as close to the project as is possible. Perfect positioning of pressure. Probably totally eliminates any bowing of the cauls in the middle, along with the 1×4’s not bending…...resulting in even pressure across the top.
I thought wing knobs stupid…...too much finger pain tightening down the cauls with even “big” wing nuts. So I used regular hex bolts and 2” fender washers on top.
I had to epoxy the carriage bolt heads into the feet, otherwise they just stripped out the feet.
Covered them all with shipping tape prior to use.
About 60% of caul pressure to start with …... then about 60% side clamp pressure, then 5-10 % at a time all around, over and over a few times until caul and clamping pressure was where it should be.
I did several practice runs figuring out the quickest way to get all these cauls and clamps in place so as to not disturb the setting glue.
The bottom cauls are taller than pipe clamps.
I get all the bottom cauls in the correct places on my assembly table by dry-fitting the boards as to where I want the cauls and pipe clamps.
Cauls need no glue protection as they are covered in cellophane and I use green Gorilla 2 inch painters tape on my pipe clamps.
I apply the glue (I did use the Titebond II Extended Setting-Time Glue for the very first time.
I hope it is as strong as any of the Types I and II and III.
If anyone has experience with the Extend I would appreciate a comment.
Laid the newly glued boards on the bottom cauls.
Hand pressed them together.
Put the top caul on top of all the bottom cauls with the bolts poking through the top cauls and moved the bolts close(er) to the work piece.
Hand pressed the joints together several times while doing the cauls, just to be sure.
When first “installing” the cauls I use my driver with about 4-5 on the ratchet with a 9/16 deep socket on the tip
Then I do the bar clamps to 60% and then use either a real ratchet with the 9/16 or the handles on the bar clamps to get all clamping done.
Just to get a little pressure going I semi-tightened down every other caul, then every other pipe clamp and then finished the other two cauls and the other two pipe clamps.
I like those little paddle clamps for the ends. Even though I made this Top and Shelf way over-sized as to length, and a little over sized as to width, I still like to get the ends clamped like that.
Then I finished …..... very quickly….......tightening all the clamps and cauls to where I wanted them.
I am glad I thought the assembly through and ran a few dry fittings, focusing mainly on the quickest way to get the cauls put together and tightened and in a logical sequence with the pipe clamps.
This process is what I ended up using.
I will post the table when finished, but suffice it to say, the glue-ups came out PERFECT.
I can (theoretically) do glue-ups from 6 inches wide to 36 inches wide.
The caul pictures are just for show. Same with the Cherry boards. No shipping tape, no glue-up of boards. Just for show. But, all ready to go.
I know many of you fellow woodworkers just grab some 2x or 4x pine pieces for cauls, or use something akin to that for cauls…....and they work just fine for you. Maybe I just had a few “wants” along with my “needs”.
Sometimes I don’t know enough to even ask the right question(s). This time I feel I did.
Hopefully this info will be of use to some one at some time.
-- We must all walk our own green mile