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Clamp Choices for Gluing Up Joints/Boards
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Author:  archtop [ Thu Dec 18, 2008 1:58 pm ]
Post subject:  Clamp Choices for Gluing Up Joints/Boards
Pretty soon I'll be gluing up a couple of soundboards. I'm mostly an archtop guy, but I will also be making a top for a nylon string guitar. I've seen Bob Benedetto use the standard Pony pipe clamps for a job like this, but lately I've been looking at the Bessey K Body Revo clamps. In case you don't know, here they are:
http://www.bessey.de/website/en/home/ne ... en/334.jsp

Are those adequate for gluing up boards? Am I asking for trouble by veering off the tried and true, beaten path? :) I know that there are also a million jigs one could make for this job, like in the Cumpiano book. Right now I want to stick with clamps. Another question about the 'ole pipe clamps.... It seems that the Jorgensen "Pony" variety have been the norm for a long time. Based on some pictures I've seen the Bessey pipe clamps look better. They have taller "feet" which gives you some more leverage when you're turning the crank on the end.

So! Basically, I want to know if those K Body clamps are way better than the pipe variety. If so, which brand is the most dependable? And if it turns out that the pipe clamps are a better bet, then which brand would you guys suggest? Opinions appreciated as always. Happy Holidays!!
-John
Author:  Kent Chasson [ Thu Dec 18, 2008 2:16 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Those parallel jaw clamps are fantastic. They are perfect for jobs like gluing up cabinet door frames where you don't want the clamp to pull something out of square. But I don't think I have never used them for guitar work.

If it's really just for gluing plates, there are better ways. If you want some all purpose clamps for the shop, it depends what you want them for. For the money, I'd invest in an assortment of cheaper bar or pipe clamps unless you have a specific need for the parallel jaws. I rarely use mine but they are worth it when you need them.
Author:  Michael Dale Payne [ Thu Dec 18, 2008 2:21 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I use an adjustable bar clamp that the bar is 1x1 1/2" rectangular aluminum tubing.
Attachment:
38183.gif

I use 5 of these. The tubing acts as a bed for the plates. I place a 3/8" thick sheet of UHMW just narrower than the plates total width on the tubing first then the plates to be joined and adjust the clamps to butt up but not tight. I then use a 1/4" wide strip of UHMW under the seem to force a tent shape at the joint. Apply the glue. Remove the UHMW strip. Place a 3" wide x 1/2" thick UHMW strip on top of the joint and weight it with 10 8 oz lead weights. I will only just snug up the clamps a touch after this. To tighten more would induce a bow that could cause the plates to move at the seam and not be glued up coplanar
Author:  Kent Chasson [ Thu Dec 18, 2008 2:26 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Oh, by the way, for small bar clamps, the Bessy LM (?) style are better than the Jorgensens. Beefier bar and longer jaw.
Author:  Jimmy Caldwell [ Thu Dec 18, 2008 2:37 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I use 3 tapered hardwood wedges about 1.5" long each. They're driven against the edge of one of the plates (one at each end , 1 in the middle) in a plywood jig. I just put a weight on the center of the plates to prevent it from bowing up. I got this technique from David Russell Young's book 30 years ago and it's the only method I've ever used for joining plates. He had some strange techniques, but this is one that works very well.
Author:  TonyKarol [ Thu Dec 18, 2008 3:18 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Nothing is simpler or cheaper than a string and wedge jig for joining tops and backs IMO. Its pretty fast, and it holds things flat as it draws the joint together ... here is mine, been used for about 200 or so tops and backs. I have replaced the string roll once after it got to kinked to unravel ...

this is version two - I added the square aluminum tubing as opposed to some 2x2 that used to be there. But the wood will work just fine. the bars are screwed to a plywood chunk underneath that you cant see - that holds the bar ends up to allow wrapping of the string around them
Author:  justink [ Thu Dec 18, 2008 3:25 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I used the same hard wood wedge idea on my top and it worked great. Didn't need anything too fancy or custom as far as jigs go and it is way cheaper than clamps.

But, as one who has worked in mfg in China - buy USA made if possible. And, no matter how well it is made steel will probably be around longer than plastic if you're in it for the long term. I would buy steel clamps - whoever makes them, instead of ones with a bunch of plastic on them.

my 2 cents
Author:  archtop [ Thu Dec 18, 2008 4:22 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Thanks for the replies guys. Lots of good methods here. The wedge procedure sounds like the one Cumpiano outlines in his book, if I'm not mistaken. For me personally, I just feel more comfortable with clamps.

Michael! That clamp looks great! Who makes it? The flatness of the bar will make a nice bed for the boards. But I'm dying to ask..... what is UHMW? Sorry, I've never seen that before. Your method sounds like one that would work great in my shop. That's all the more reason for me to find out what UHMW is!! :)

Kent, thanks for the head's up on the Jorgensen vs. Bessey. Unfortunately I've already bought a couple of the Jorgensen. I only got 2 and I need a lot more. Maybe I'll try the Bessey this time.

-John
Author:  Hesh [ Thu Dec 18, 2008 4:29 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
And here is another method for you where you don't need any stinkin..... :D clamps or wedges......

The tape method:

Attachment:
DSCN2446.jpg


There is a toot in the archives if anyone is interested.

BTW what Coach Tony shows is what I used until I tried the tape method and it works very well. But I pitched the jig when I moved because I never use it anymore. Also it is known as a Spanish tourniquet.
Author:  Dave Stewart [ Thu Dec 18, 2008 4:44 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
He's talkin' archtop plates.....big mother chunks of wood (often wedge shaped) up to 1 1/4" thick at the joint. (Try tape for that!)
You'll need clamping pressure. Frankly, the besseys are not a bad approach ....clamping pressure must be parallel to the flat underside to get a good seam (don't ask me how I know).
Author:  archtop [ Thu Dec 18, 2008 4:54 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Dave, your guitars are real beauties! And since you know exactly what I'm doing, why don't you tell me what you prefer using? Should I stick with the typical pipe clamps? Do you think the aluminum bar variety posted above would be as effective?
-John
Author:  ChuckH [ Thu Dec 18, 2008 5:35 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I like the style and type I saw on one of John Mayes videos. He use pipe clamps, but they are kind of heavy. I could see where the clamps Michael P uses would be lighter and also have a flat area on the clamp that would help hold the two sides down.

Image
Author:  Steve Walden [ Thu Dec 18, 2008 6:33 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
archtop wrote:
Thanks for the replies guys. Lots of good methods here. The wedge procedure sounds like the one Cumpiano outlines in his book, if I'm not mistaken. For me personally, I just feel more comfortable with clamps.

Michael! That clamp looks great! Who makes it? The flatness of the bar will make a nice bed for the boards. But I'm dying to ask..... what is UHMW? Sorry, I've never seen that before. Your method sounds like one that would work great in my shop. That's all the more reason for me to find out what UHMW is!! :)
Kent, thanks for the head's up on the Jorgensen vs. Bessey. Unfortunately I've already bought a couple of the Jorgensen. I only got 2 and I need a lot more. Maybe I'll try the Bessey this time.

-John

Ultra High Molecular Weight Polyethylene a self lubricating plastic that is used to keep glue from sticking to the clamps.
Author:  Dave Stewart [ Thu Dec 18, 2008 7:50 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
archtop wrote:
Dave, your guitars are real beauties! And since you know exactly what I'm doing, why don't you tell me what you prefer using? -John

Thanks John. Still working on the best approach. I'd start with simple pipes since they're cheap. If dealing with rectangular plates, they're fine. Getting a perfect joint between wedge billets is tricky business...even a "no light" joint can be buggered up when clamping. I broke apart one of my last sets just after gluing because I didn't like what I was seeing. The problem is that all the clamping force on the tent-like assembly is concentrated on ONE EDGE (the underside) of the joint (rather than the centerline of the joint as it should be). Too much force & the oposite edge wants to rotate open. I'm toying with pre-gluing blocks to the top surface (or pre-sawing at waist locations to get clamp force axis closer to centerline) to try to improve this operation.
Author:  archtop [ Thu Dec 18, 2008 8:00 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Thanks Dave. And all this time I was trying to tell myself not to be too freaked out about dealing with wedge shaped boards!! idunno I think I'm going to go the pipe route for now. It seems to be a tried and true method. As far as the wedges go, do you have any tips? I'm just gonna go super slow and make sure everything is ok. It can't be impossible, otherwise I wouldn't be seeing so many wedges for sale from all the tonewood vendors. So if you have any tips or past experience gluing up these suckers please let me know.
-John
Author:  jfrench [ Thu Dec 18, 2008 9:05 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I like to keep simple jobs simple (and inexpensive).

I just make the soundboard in a slight wedge... 10mm or so over its length. Then clamp two straight boards against the outside of it. Remove soundboard, add glue, push forward into the wedged boards for more pressure.

I use a weight to keep the joint flat.

Simple and easy.

The tape method Hesh showed is another great method.
Author:  Chas Freeborn [ Thu Dec 18, 2008 9:33 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I use the Bessey K's for top glueing. Once you use K's you'll never look back. I sold all my other bar clamps. Get the holder upper blocks too. I'll try to get a photo of my rig posted up soon.
Author:  Bob Garrish [ Thu Dec 18, 2008 9:42 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I now use a setup like Chuck H, but with a solid plate underneath (instead of cross bars) and the 'supporting bars' on top are perpendicular to the clamps instead of parallel. I have three supports on each side and clamp until the wood starts to buckle (ie: the clamps actually start crumpling it in). I use well-made knockoffs of the Bessey K's, as well. I've got three of them and I've essentially gone to only using those, C clamps, and vacuum clamping for everything now (Bessey and/or C where I want extreme pressure, vacuum where I can get away with less)

I first used it in my 'big roundup' test where I tried different jointing methods, glues, and clamping pressures to figure out the best combo. One of the absolutely conclusive results was that, if you can prevent the top pieces moving vertically, more pressure is never bad and usually good (up to the point that the wood is failing laterally, of course!).
Author:  Tai Fu [ Sat Dec 20, 2008 9:27 am ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I think the tape method only works with hide glue since hide glue pulls the joint tight as it cures so as long as the joint is good (no light escaping through when you hold the piece together under a light) clamping isn't even needed (rub the joint together) besides binding tape can exert quite a pressure.... I used it for wooden bindings with titebond 3 and it made a perfect joint.
Author:  Rod True [ Sat Dec 20, 2008 11:33 am ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Tai Fu, I'm afraid I'll have to disagree with you. The tent method will work just fine with what ever type of glue you choose. Just add more tape (less space between the pieces) and increase the angle between ends to add more pressure.
Author:  Hesh [ Sat Dec 20, 2008 11:57 am ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Tai Fu I have used the tape method with Titebond (original) many times and it works great. You are correct though that HHG and it's ability to pull wood together is even better.

The trick with all jointing is to have a perfect, no light showing through any where, joint prior to gluing and clamping the plates. I don't think that any method is going to make up for a bad joint.
Author:  DYeager [ Sat Dec 20, 2008 11:58 am ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
My rig looks like Tony's, except that mine is all wood. I drive those wedges until the rope starts to crush the edges of the plate, and there's no worrying about the wood bowing or tenting with those wedges pressing down on the crossbars.

Do you have a cocking problem? I can see how there might be with an archtop set. I would try balancing the clamping, with at least as many clamps over the "peaked" face as on the bottom. In fact it might be possible to slightly overbalance the clampup, with more clamps over the peak. Also, the clamps can flex - pipe clamps flex a lot - and this will try to force a curve in the plate, resulting in the top of the joint (side away from the clamps) opening up.

When it comes to sanded joints, taped joints, squeezeout, thinned glue....I can feel a rant coming on. A lot of the folks looking this site over are beginners, and their questions show that they aren't just beginning luthiers, but neophyte woodworkers. Just because a not-too-widely accepted technique works for me, under some circumstances, doesn't mean that I should be promoting it to someone who has not got the backgroung to recognize possible pitfalls. I would explain very plainly that this is how I do it, and that there are other, possibly more foolproof techniques. Provided I know, of course....

Dan
Author:  Todd Rose [ Sun Dec 21, 2008 9:34 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
jfrench wrote:
I like to keep simple jobs simple (and inexpensive).

I just make the soundboard in a slight wedge... 10mm or so over its length. Then clamp two straight boards against the outside of it. Remove soundboard, add glue, push forward into the wedged boards for more pressure.

I use a weight to keep the joint flat.

Simple and easy.



Now, that's a very cool idea I had never heard of or thought of. I might just try that on my next. Thanks, Josh!
Author:  sbjguitars [ Mon Dec 22, 2008 1:21 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
I know some guys love te K bodys but I can never get them to work right, I much prefer the old school pipeclamps with painted black pipes, not the glavinized. For gluing tops I use the method described earlier. I screw some scrap wood down on a work surface slightly smaller than My top and then weight down the middle normaly with a waxed scrap of plywood under my arbor press or other heavy tools laying around. ON some uneven tops were the sides are not even I just run a series of screws into my work board to conform the the edges, if it gets a little deformed it doesn't matter, it'll get cut off.
Author:  Michael Dale Payne [ Mon Dec 22, 2008 1:55 pm ]
Post subject:  Re: Clamp Choices for Gluing Up Joints/Boards
Filippo,

recon you have enough weight on there idunno laughing6-hehe
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