calling all caul users

I very seldom use them but will on occasion. Mine are simply a 1x4 or like material use on edge. Flat will work fine if you have a clamp every 24 inches or so. I will say that they do help to insure more even pressure and contact but in some cases are in the way of a 20+ clamp glue up.

I have given a lot of thought on the curved ones and IMHO the middle of the caul still exerts the most pressure so unless you are able to gauge the center pressure and bring the end pressure to equal that all along the distance it only replaces one clamp, the center one.

I could be dead wrong but I believer a straight caul along with a few less clamps would be just as good or better. Now if you only have a few clamps this might be a good option.

They don't need to be hard, or strong. I am using 2x4's cut in half, and then put a fair curve as best I could on mine. I use them a lot. It lowers the number of clamps, and provides a more even glue up.

I use the 4' 2x2s meant for porch railings because they tend to be pretty straight. I taper them with a hand plane. One stroke each way from near the middle to the ends, then a few inches further from the middle, and so forth - about 4 strokes to get to a foot long for the last stroke.

I made mine out of Ash 1x2s glued together. I planed them on all sides (the Ash I have is fairly rough), stained (to make 'em pretty), and several coats of poly (makes scraping glue easy). They're drilled for 3/8" carriage bolts and wingnuts.

"pretty" What the hell for??? I covered mine with packing tape on the curved side to prevent glue from sticking.

Why not? Wood should be pretty. ;-)

Thanks for sharing the information. I never saw cauls used before so I did a little googling.

Electric Comet wrote in news:n1j47i$4cm$ snipped-for-privacy@dont-email.me:

Like others have said, I don't think the curve is critical. You just want a slight belly in the middle (*).

Well, you don't want them so hard they mar whatever it is you're clamping. And you want them to flex when you clamp.

I think most people do what I do, and use whatever scraps of wood are the right length to make cauls as needed. And then save them to use again.

John

(* if you make a fair curve by eye, it will be elliptical, or darn close. Just the way our brains work)

------------------------------------------------- See Cambers on abpw.

Lew

the curve is critical and may depend on the caul material it is a fine line between being useful and not working correctly

they are an interesting addition to the clamping phase of woodwork

and how about the curve did you just eyeball it

not a bad idea simple and cheap and effective

sounds simple enough what type wood did you use

douglas fir or hemlock or something else i always presume 2x4 is doug fir but you never know

this is what caught my eye in the catalog but the price was laughable

if it is flat it is not a caul that is the whole point anyone that thinks that the curve is not significant is missing the entire point of a caul

people with years of experience are often wrong if they realize it then they become experts if not then they maybe they are still in pursuit of expertise

Like many woodworking techniques/tricks, what starts out as possibly an accident or a very modest adjustment, often get exaggerated over the years because we all know more is better, right?

The cauls I've always seen and used have an almost imperceptible curve to them. Some of the ones I've seen on the web are ridiculously curved. They don't have to be curved very much at all.

I've never actually cut a curve in a caul. I just find scrap wood than has a slight bow in it already... like most scrap wood, right? Why else do we have a jointer? :-)

I would guestimate that on a 36" wide panel, the bow in a caul need only be 1/16" higher on edge than in the center. And that might be too much. A caul is simply keeping the boards flat and stopping them from popping up from the force of the clamps. You don't need much pressure at all to accomplish that.

That would be my thoughts and the size/length of the area to be clamped IMHO would also change the dynamics.

You might want to look up the definition of a caul.

Better yet,

The surface of a press that makes contact with panel product, especially a removable plate or sheet. (woodworking) A strip or block of wood used to distribute or direct clamping force.

See above.

Correct but people with years of experience that use straight flat cauls get results that stand the test of time.

A caul merely insures more direct pressure in places that a clamp is not placed. There have been numerous articles as to how closely clamps should be placed on straight flat cauls.

AAMOF a curved caul could be a problem with a lightly built project if you are trying to insure the outer ends of the caul make contact.