Tips/techniques for flat glue-ups?

[Phil Thien]

With my drum sander now gone, I'm going to need to be more careful in getting the faces of my panel glue-ups flat, so I don't have to remove too much material.

Woodcraft sells these:
http://www.woodcraft.com/product/2000321/1858/woodriver-clamping-system.aspx

And Rockler sells these:
http://www.rockler.com/product.cfm?page=10711&site=ROCKLER

The Woodcraft units get better reviews, look easier to assemble, etc.

Am I missing any other vendors of a similar clamping "system" which may be superior to these?

Will these work as well as making some cauls using Mike Henderson's tutorial? The thing that concerns me a bit is that these panel clamps don't use any camber so I'm not sure how good a job they'd do at keeping the boards flushed-up? Mike's cauls have camber, so they will apply more pressure at the mid-point than at the edges.

Any thoughts?

[Gary Pennington]

I can't offer help, but I'd be interested to hear experiences of anyone who has used the Rockler equal pressure clamps.

Thanks

[Bill Huber]

I think those are both the same clamps, I had a set and IMHO they are just not that good. Very hard to work with and I didn't think they did a very good job.
I now just use cauls and have found they do a good job, I also use Quick Clamps on the end of the board to make sure they are in line with each other.

[Rick Lizek]

Curved cauls are the superior method. As long as your boards are the same thickness you will get perfect registration. I can glue up a 4 x 8 panel myself and only have scrape off the glue and finish sand. I also plane the boards to finish thickness before gluing up. Forget those other clamping systems. Cauls use your existing clamps and have other uses such as carcase clamping and more. Simple to make as well.

[Bob Vallaster]

Phil,
I have the Woodcraft item. From looking at both ads, they appear to be indistinguishable.
Mine work, but they're a bit of a wraslin' match to get a panel into. I usually (1) spread the clamping heads to a usable distance, (2) use an over-thick spacer to hold the bars apart enough to slide in a plank with wet edge(s), (3) remove the bar shims when full panel is in place, (4) take up clearance with the screw handles and begin squeezing glue. Adjust boards as necessary, apply additional clamps as necessary and bring up to full squeeze.
For anything above ~15" length, I use additional clamps, so it's rare that I use just the 4-ways. They do not reduce the tool count in the garage, and they're clunky to store. In hindsight, I'd rather just have clamps and separate cauls.
As to your last point. When I built the wooden parts for the 4-way clamps, I applied some arch to the bar (with plane and sander) to ensure that the mid-span would have compression, just like cauls.
I keep the inside face of the clamps waxed to facilitate removing glue after each use. Masking tape would do the same job.

Bob

[Stew Hagerty]

I saw these "Bowclamps" at last year's Woodworking in America Conference. They looked awsome. They have just the right amount of radius, they have a T-slot across the top to register an F style clamp on each end, and they have a hanging strap. All in all w well thought out product. Personally I have a pair of Woodpeckers Flat Bar sets and four of their Side Kicks for the edges so I didn't feel the need to buy the Bowclamps. Unfortunately they both are some of their "One Time Tools" or I would recommend them to you. Anyway, here is a link to the Bowclamp website:

http://www.bowclamp.com/index.html

[Mike Henderson]

Of course, you can make your own (http://www.mikes-woodwork.com/Cauls.htm) cauls for maybe $2/caul if you don't want to spend that much money.

Mike

[Phil Thien]

Of course, you can make your own (http://www.mikes-woodwork.com/Cauls.htm) cauls for maybe $2/caul if you don't want to spend that much money.

Mike

LOL, I know, I know, I mentioned your tutorial in my original post. Thanks for posting the link, I think this is fate telling me to try the cauls first. Or, at least it is Mike telling me to try the cauls first. Either way, I should try the cauls first.

[frank shic]

there's also the plano press system, phil.

[Rick Lizek]

there's also the plano press system, phil.
The cauls are better and cheaper then the Plano System.

[Phil Thien]

BTW, not that I will buy either, but the designs from Rockler and Woodcraft differ in that the Rockler design requires that you drill holes in a 2x4 that you then split, to get those notches. The Woodcraft model uses the supplied plastic pieces. Not sure about the rest of the mechanism, though.

[Zach Callum]

If you process your lumber so that it is flat, straight, and a consistent thickness, you will have less to worry about.

[Mike Henderson]

LOL, I know, I know, I mentioned your tutorial in my original post. Thanks for posting the link, I think this is fate telling me to try the cauls first. Or, at least it is Mike telling me to try the cauls first. Either way, I should try the cauls first.
Sorry, I guess I didn't read all of your original post.

Mike

[Phil Thien]

Sorry, I guess I didn't read all of your original post.

Mike

That's alright, don't go away, I've got a question for you. :)

Do cauls cause any problems at the glue line when gluing-up panels?

Your tutorial says to wrap the cauls in tape to prevent the cauls from getting glued to the panel, which is a great tip.

But what happens to the glue that would otherwise squeeze out and form a bead? Does the caul drive it into the panel? Is there extra sanding involved to get it out? Any tips in this area? Use less glue? Don't worry about it?

Thanks for the great tutorial!

[Mike Henderson]

That's alright, don't go away, I've got a question for you. :)

Do cauls cause any problems at the glue line when gluing-up panels?

Your tutorial says to wrap the cauls in tape to prevent the cauls from getting glued to the panel, which is a great tip.

But what happens to the glue that would otherwise squeeze out and form a bead? Does the caul drive it into the panel? Is there extra sanding involved to get it out? Any tips in this area? Use less glue? Don't worry about it?

Thanks for the great tutorial!
I'm sure the glue squeezes out some in the area of the cauls but I've never had a problem with it. I always sand a panel so that takes any glue squeeze out off.

You definitely want something to keep the caul from getting glued to the panel - that would be a mess and an embarrassment. Packing tape works fine for me.

Mike

[Bill Huber]

That's alright, don't go away, I've got a question for you. :)

Do cauls cause any problems at the glue line when gluing-up panels?

Your tutorial says to wrap the cauls in tape to prevent the cauls from getting glued to the panel, which is a great tip.

But what happens to the glue that would otherwise squeeze out and form a bead? Does the caul drive it into the panel? Is there extra sanding involved to get it out? Any tips in this area? Use less glue? Don't worry about it?

Thanks for the great tutorial!

I am not Mike but I can tell you..... What happens, nothing, after you let it set for an hour and take all the clamps off you just scrap the glue just like normal.

[Neil Brooks]

I haven't personally used any of these gizmos, Phil, and I am anything BUT anti-gizmo.

That said ... I use shop-made cauls. I zip across the slightly curved end with paraffin, before use. They work great.

My gut tells me that these particular gizmos are a solution in search of a problem.

[Sam Murdoch]

Though if you truly want to spend money the Bowclamp looks like a pretty decent rig. I have no experience with them though - I am in the "make your own caul clamp" camp.

If you really really want to spend money, check this out http://www.youtube.com/watch?v=5d4ondRBfqs Larry's Clamp.

[Phil Thien]

Though if you truly want to spend money the Bowclamp looks like a pretty decent rig. I have no experience with them though - I am in the "make your own caul clamp" camp.

If you really really want to spend money, check this out http://www.youtube.com/watch?v=5d4ondRBfqs Larry's Clamp.

I've seen the Bowclamp, and they do look great. But I'm going to save some moola, if possible.

"Larry's Clamp" is interesting. Although he isn't actually putting any glue on those boards. Something tells me if he did, he wouldn't be moving along quite so fast, because the boards can still shift around a while after the clamps go on. At least, that has been my experience.

[Phil Thien]

I'm sure the glue squeezes out some in the area of the cauls but I've never had a problem with it. I always sand a panel so that takes any glue squeeze out off.

You definitely want something to keep the caul from getting glued to the panel - that would be a mess and an embarrassment. Packing tape works fine for me.

Mike

Okay, thanks for everything, Mike.

[Phil Thien]

I zip across the slightly curved end with paraffin, before use. They work great.

I had thought of using wax but the beauty of Mike's tape idea is I don't have to worry about wax residue transferring to my glued-up panel and causing finish problems. I doubt wax would cause a problem, but with tape I don't even have to worry about it.

[Dick Mahany]

Figures....I read this thread too late ! Spent the day making a number of panels from 3/8 - 1/2" thick from QSWO. When I resawed the stock, and planed to thickness, it went cattywhompus on me. The glue ups were less than I had hoped for and I resorted to the wide drum sander, but lost more thickness than I wanted. If I had thought about Mike's excellent and totally practical solution, I'd be a much happier camper !

[Ryan Mooney]

I had thought of using wax but the beauty of Mike's tape idea is I don't have to worry about wax residue transferring to my glued-up panel and causing finish problems. I doubt wax would cause a problem, but with tape I don't even have to worry about it.

Another thing that works well is butcher paper ("wax" side down). The tape is a more targeted solution.. but if you have a case where you need something wider its cheap (per foot...) and works well. We already have a large roll that we use for wrapping meat so it was a natural grab for glue ups :D

[frank shic]

dick, no one will ever know after it's all assembled ;)

[Jim Foster]

I had three of the clamps shown in the woodcraft picture for many years. I thought they were a real pain to get set up when gluing a panel. I was never able to use them without my blood pressure going sky high trying to get them assembled on a panel in a reasonable time. The end result was nice though. I gave mine away years ago. I have been using Bessey K-Clamps on a flat bench lately, and will be making the cauls Mike H. provides a tutorial for when I start the next project requiring panel glue-up.

[glenn bradley]

BTW, not that I will buy either, but the designs from Rockler and Woodcraft differ in that the Rockler design requires that you drill holes in a 2x4 that you then split, to get those notches. The Woodcraft model uses the supplied plastic pieces. Not sure about the rest of the mechanism, though.

I had the Rockler ones. The cauls are simple to make and more resilient than the plastic screw-ons. They function as designed. They will not press poorly milled boards into submission. I sold mine at a fair price as my druthers move me in a direction that finds me doing little in the way of large panel glue-ups. For the occasional panels I do, parallel clamps have worked well. The little end cauls in this pic actually weren't required but I had them on to demonstrate them for someone.

227997

[Mike Henderson]

I appreciate people saying, "Mike's cauls" but all I did was document a way of making them (and there's many ways of making them). Cauls have been used by woodworkers for centuries. They're a well known and well proven technique for getting flat panel glue-ups.

I'll just reiterate the process when using them.

1. Use spacers under the glue-up so you can get your clamps under the cauls. I usually use a couple of 2x4s on edge, or even flat. Put your bottom cauls on the 2x4s.
2. Clamp the cauls before you clamp the panel. If you put your caul clamps inside the work it'll be easier to put them on. If you put the caul clamps outside the work, you really need two people to do the clamping. Clamp the cauls down tight enough to bring the boards into alignment. If the ends of the panel boards are not aligned, use a single clamp and two small cauls, as shown by Glenn's posting above.
3. Clamp your panel in the usual fashion. The pressure of the clamps will pull the boards tight - the boards will just slip along the cauls.

You can remove the cauls once you get the panel clamped - the pressure of the clamps will keep the boards from slipping. That will allow you to clean any glue squeeze out off. Often I just leave the cauls on until the glue sets.

Mike

[ian maybury]

To ask a question. Cauls are curved to apply some inwards pressure as they are done up. Is there is a risk of their bowing the assembly of edge to edge boards? As in if say the curves or the stiffness of the strips are not symmetrical, or not the same on both cauls?

ian

[phil harold]

I appreciate people saying, "Mike's cauls" but all I did was document a way of making them (and there's many ways of making them). Cauls have been used by woodworkers for centuries. They're a well known and well proven technique for getting flat panel glue-ups.

I'll just reiterate the process when using them.

1. Use spacers under the glue-up so you can get your clamps under the cauls. I usually use a couple of 2x4s on edge, or even flat. Put your bottom cauls on the 2x4s.
2. Clamp the cauls before you clamp the panel. If you put your caul clamps inside the work it'll be easier to put them on. If you put the caul clamps outside the work, you really need two people to do the clamping. Clamp the cauls down tight enough to bring the boards into alignment. If the ends of the panel boards are not aligned, use a single clamp and two small cauls, as shown by Glenn's posting above.
3. Clamp your panel in the usual fashion. The pressure of the clamps will pull the boards tight - the boards will just slip along the cauls.

You can remove the cauls once you get the panel clamped - the pressure of the clamps will keep the boards from slipping. That will allow you to clean any glue squeeze out off. Often I just leave the cauls on until the glue sets.

Mike
where is " Mike's cauls" documentation
I need to make a set!
thanks

[Rick Lizek]

The key is to make your cauls from the same material and it's best to make a master to copy all your cauls from once you figure out your curve. Pattern bit to copy your master copy then you don't have to worry about bowing your panel. That's more likely to happen if your stock is resawn and not allowed to acclimate so don't blame the cauls for warping. Also of jointing edges on your jointer and your jointer is set at 89 degrees, if you flip your alternate faces you can still get perfect alignment all the time if you ate conscious of what you are doing. I've been using curved cauls for 40 years with perfect repeatable results. It's such a simple concept and haven't seen it really covered as much as it should in the hobby mags.

[Mike Henderson]

where is " Mike's cauls" documentation
I need to make a set!
thanks
Try here (http://www.mikes-woodwork.com/Cauls.htm).

Mike

[Mike Henderson]

To ask a question. Cauls are curved to apply some inwards pressure as they are done up. Is there is a risk of their bowing the assembly of edge to edge boards? As in if say the curves or the stiffness of the strips are not symmetrical, or not the same on both cauls?

ian
I'm sure there's some risk but I've never seen that happen or heard of it. You'd have to have MUCH "stronger" cauls on one side, with a steep bow, and very flexible cauls on the other side with essentially no bow. If you make your cauls out of the same material (I use kiln dried 2x4s) you're unlikely to get that much difference in "strength" between the two sides. Additionally, the material of the panel has some strength - unless you're gluing extremely thin stock.

Think of how difficult it is to bend stock when you're doing laminate bending. There, you have two cauls with opposite bow (one convex and one concave) and you have to work hard to get the material to take that shape. And then you have springback.

Mike

[ian maybury]

Thanks for that guys, sounds good. Just wondering how precise one needs to be as I've not used cauls yet.

ian

[Mike Henderson]

Thanks for that guys, sounds good. Just wondering how precise one needs to be as I've not used cauls yet.

ian
Some people make cauls out of jointed (straight) stock. I believe a bowed caul is a bit better but the jointed cauls work for them.

When I took woodworking classes at Cerritos College, the instructor taught jointed cauls - probably because it was easier for the students to do and he didn't have time to teach the bowed cauls. If you put your caul clamps in as much as possible (toward the center of the panel) they seem to work fine.

Mike

[Rick Potter]

Thanks Mike,

I bookmarked your info site. Been wanting to build some for quite a while. Love the marquetry.

Rick Potter

[Kent A Bathurst]

Make and use cauls. Mike's instructions seem pretty straightforward.

Long ago, I made a clamping "system", if you will. It includes:

2 x 2 HM cauls. They are not curved. Instead, I taped a dime to one end, set that down on the jointer outfeed, and ran it across the jointer multiple times to get a long bevel. Flip end-for-end, tape 2 dimes this time, repeat. I left a 2" flat section in the center. I have not yet done any veneer work, for which I'd guess curved cauls would be important. The flat spots in the middle of tte cauls straddle the glue joint, and I do one joint at a time.
>>> Important: I put 3/8" x 3/8" kerfs or grooves across the cauls that straddle the glue joint, so it doesn't smear the glue. This is important for open-pored wood like the QSWO I often use. Also - cello packing tape on the face of the cauls.

End blocks. Small squares of hardwood, face with cello tape, and with the 3/8" kerfs. These are used on the very ends of the joints to be sure they get aligned.

Caul stands. Scrap wood to make stands for the bottom cauls. These have a "U" cut in the vertical sections to hold the 2 x 2 cauls, and the cauls nest inside them. Maybe 12" - 16" between the vertical sections.

Clamp stands. Me likey pipe clamps. I have small stands of scrap wood with a 2/3 diameter section of 1" PVC pipe screwed to the top. The 3/4" pipe snaps in place to hold the clamps.

Pipe spacers. More chunks of 1" PVC that snap onto the pipes, to hold the "above the wood" pipe off the workpiece by 1/8" or so. Black pipe + wet glue = very pretty stains.

Clamp orientation. Over-under-over-under with the pipe clamps. If there is room for one more clamp, then you didn't use enough clamps. I alternate the direction of the pipe clamps, so that the handles don't interfere with each other.... I can get more clamps on this way.

6" C-clamps. The height of the caul stands and the clamp stands was determined by the space I needed for clearance for 6" C-clamps to crank down on the cauls.

Sequence: cauls on stands. boards on cauls. Glue the joint. barely squeeze with the pipe clamps...squeeze is too strong a word for it. Get the boards aligned is all. Then the top cauls and c-clamps. Snug them down pretty tight, because the pipe clamps will still pull the boards together with the cauls tight, but it won't work in reverse....if you tighten the pipe clamps first, you can't get the joint flat no matter how hard you try, and no matter how big your hammer is.

Everything is exactly the same every time. After 12 years or so, there is zero drama with glue-ups. I have a small bead of glue squeeze out, and after 45 minutes or so, I release the cauls and clamps, use a beat-to-heck card scraper that is all black with glue stain to peel off the glue bead. Any offset between the boards is always slight enough to be dealt with by a couple passes with a [good] card scraper.

[phil harold]

Try here (http://www.mikes-woodwork.com/Cauls.htm).

Mike
You the MAN!
thanks!

[trevor adair]

I have the Woodcraft set and use them for cabinet doors. I have had great luck using them to pressure the t&g together and keep things flat. I have found them super easy for this purpose, just lay them down slip the door in and tighten.. I cannot speak to them for panels because I have the Plano panel clamps that have worked very well for me..
228059

[Paul Saffold]

+1 for "Mike's" cauls and it is a real good idea to do a dry run first.

[Rick Potter]

Hmmmm,

I just remembered that sometime back in the stone age, my brother gave me a set of the hardware for a pair of this type clamp. Trevor's post about the panel doors makes me want to go out in the shed and find them. Might come in handy.

I have stuff out there I don't even know I have, if that makes sense. A bowl maker for a Shopsmith, or a Craftsman pin router, or a bending tool for doing steel for example...all in boxes, most given to me by relatives, or when my dad died.

Still gonna build some cauls.

Forgetful Rick

[Kent A Bathurst]

Coming soon to a Classifieds posting near you: Rick finds the stuff he forgot he had!!! :D

I am almost always surprised when I dig through the 2 drawers or the back corner room that are dedicated to "out of sight, out of mind" stuff. That's where most of my for sale stuff comes from. I always figger I've found it all. But....nope.

[Phil Thien]

Still gonna build some cauls.

Forgetful Rick

Maybe you already have. :p

[Troy Turner]

Phil -

I remember seeing these a while back. Looks like a pretty good idea :)

The ones from brianalt:

http://community.woodmagazine.com/t5/Info-Sharing/Clamping-Cauls/m-p/170642

http://community.woodmagazine.com/t5/Tools-and-Tool-Buying/Show-Us-Your-Clamping-Tips-and-Tricks/td-p/160358

[Matt Day]

Great thread! Mike, thanks for reposting your tutorial. I remember seeing it a while ago, but seeing it again a couple days ago sparked my interest since I have some glue ups coming up soon. I bought a few 2x4's after work yesterday, and knocked out 3 sets of 2'ers in an hour or two. I look forward to using them!