Panel cramps

[Derek Willis.]

I thought this was quite interesting.
Adjustable Panel Cauls


When gluing up a solid-wood panel, one of the challenges is keeping it flat while the clamps are tightened down. For a long time, my solution to this problem was to clamp cauls across the panel. But on too many occasions this "jury rig" method turned out to be awkward and generally unsatisfactory. So I determined to come up with an improvement.

The result is the set of adjustable panel cauls you see at work in the photo above. The construction details are shown in the drawings below. Each caul consists of two hardwood "beams" that sandwich the panel. A slot running down the middle of each beam accommodates the adjustable clamping mechanism that connects the two beams. This is simply a carriage bolt that passes through a foot and is tightened down with a large, plastic wing nut.



Using the cauls is pretty straightforward, but there are a couple of fine points I should mention. You don't want to inadvertently glue the cauls to the panel. To avoid this, you can place wax paper between the beams and the panel or wax the edges of the beams. Then snug the carriage bolts up close to the panel before tightening the wing nuts. This will better focus the pressure across the panel.

 

[MikeG.]

Good idea Derek..........and thanks for posting this.

Like you, I have always just clamped a couple of battens across the board ends, but that is 4 clamps per panel........and if you are doing a number of panels in one session you can soon use up all your clamps. Furthermore, they get in the way.

As I am in metal-working mode at the moment, I might have a look at making a couple of these out of 2x1 box section mild steel.

Mike

 

[Racers]

Hi,

I used to have some sash cramps using cramp heads and 2x1 box section they where far to heavy to use, so they are now all wood, apart from the heads :wink:


Pete

 

[Derek Willis.]

Mike, that's the ideal answer, in steel, very much like the Plano cramps.
Derek.

 

[wizer]

Thanks Derek, I really like at idea. Something tells me I may need that very soon.

 

[MikeG.]

Sounds like a project on the way Tom.....?

 

[John. B]

That's a good idea Derek,
Always a problem, to keep boards flat even when cramping from both sides.
Well done
John.B