Pipe Clamp Tips and Tricks

[rick7938]

Although I would love to have a shop full of parallel clarmps, my budget only allows me to have a variety of pipe clamps. They work pretty well, but they do not always clamp with the jaws parallel, so they can deflect material glue-ups such as solid panels and mortise and tenon joints such that they are not level. I use cauls for the panels, but that does not always completely cure the problem.

Anyone have any tips or tricks to make these pipe clamps a little more user friendly?

Thanks for any feedback.

[woodArtz]

bump!

[WoodWrangler]

Wish I could offer something here .... but mine just hang on the wall 99% of the time.

I think I'd have to find a way to get some of those Stanley Bailey clamps we've all been chatting about. They are cheaper than a decent pipe clamp and so much better.

[Kdub]

i'm sure you always do this but clamping alternating clamps top and bottom seems to help me. also at the ends using wood screw clamps or pieces of wood and a C clamp with plastic or wax paper to keep the glue that squeezes out from messing up my screw clamps that helps keep the pieces aligned but i'm not sure if it helps with the sliding, i suppose dowels or bisquits would be of some help.
good luck
kurt

[Trent Mason]

Rick,

I use pipe clamps almost exclusively as my budget has limited me to using them. I do what Kurt says and alternate clamps on either side. That has always worked well for me. Also, I'm not sure if you got your clamps for Harbor Freight, but if you did, don't drop the on the ground, they will break easily.

Cheers,

Trent

[JackLeg]

There's an article in a recent issue of one of the WW mags, maybe Wood, that details how to build cauls to be used for this exact purpose.

[Chuck Seehuetter]

Here are a few good tips from Wood magazine.

http://www.woodmagazine.com/woodwork...h-pipe-clamps/

[Tarhead]

I still use pipe clamps for long glue-ups and I have to hold my mouth just right to get everything to line up. (you did read the instructions about how to hold your mouth didn't you?) One thing you can do is put a small brad half way into one side of your glue-up and snip off the head to create a little spike to keep the pieces from sliding around when you clamp.

For panel glue-ups with pipe clamps (or K bodies for that matter) I lay the panel pieces face down on a flat reference surface (tablesaw top, old piece of countertop on sawhorses, etc) with something flat and non-stick on it. I used freezer paper plastic side up or wax paper before I got an assembly table with a waxed MDF top. Then apply glue to the edges of the glue-up and push them together loosely with your pipe clamps (pipes over the panels). Lay down some wax paper on top of the panel and put a few cauls (2X4s work well for me) on edge in-between the pipes and overhanging the edges of your assembly surface. Then clamp the cauls to the assembly surface with some C Clamps or small F clamps on each end of the caul. This will apply downwards pressure and insure your face is smooth and level. Finish tightning the pipeclamps to close up any gaps. The wax paper helps things slide. The booger in this is you've only got a few minutes to get everything right before the glue starts to set so get your ducks in a row before you start spreading glue.

[tom hintz]

I feel another story coming on......
Probably the biggest "secret" about using pipe clamps (any clamps really) is applying way too much pressure. I was convinced all of my pipe clamps were junk until I had a veteran woodworker stop by once when I was making a panel. He whapped me across the knuckles with a cutoff I had laying around while I was tightening down the clamps. Then he explained why and I have never over tightened clamps again, pipe, parallel or anything else.

If you see glue rise from the joint - THAT'S IT! Tightening more than that just pushes the glue out and distorts the wood, easily causing bows and other defects in panels that we blame on junk clamps. Alternating clamps top and bottom is a good suggestion (noted elswhere in this thread) as is spreading the glue evenly across all of the joints to prevent hydraulic issues that can make things crooked as well.

Using a bunch of clamps with light pressure is way better than a few squeezing the snot out of the project. To me, the biggest thing I see people do wrong is tightening clamps down way too much. I probably need to whap a bunch of the people around here on the knuckles but I suspect some are bigger and/or meaner than me so we'll let it go with this message....

[rick7938]

Thanks for all of the feedback. I will admit that I am guilty of overtightening the clamps. I will try to refrain in the future and see how that improves my luck with the clamps.

[DaveO]

One thing that I have done while doing panel glue-ups, is not related to the clamping aspect, but if done right can help with many clamping problems.
First lay-out your boards that will be the panel in the best orientation. Mark their position. Then take each board and joint the edge with the opposite face against the jointer fence. By doing that if your jointer fence is off by as little as .5º that will be canceled out by one edge being 90.5º and the other being 89.5º. Then when all your boards are jointed stack them on edge on top of each other, as they will be glued together but in a vertical orientation. If the stack stands without leaning or wavering, you are ready for a glue up. Even spread of glue and firm but not Herculean clamp pressure, alternate clamps on the top and bottom.

MTCW,
Dave

[Bas]

Originally Posted by tom hintz

I feel another story coming on......
Probably the biggest "secret" about using pipe clamps (any clamps really) is applying way too much pressure.

Hear hear. I was never able to figure out how my projects would be perfectly square during a dry fit, but then be off during glue up. It was because I cranked those clamps down hard enough to turn coal into diamonds (well, not really....see any Festool in my shop?). I think your idea of rapping people on the knuckles is a sound teaching method. I sure could have used a good smacking.

[PeteQuad]

I have 4 parallel clamps. If I am worried about something not clamping square, I will start with two of those to keep things square and then add the pipe clamps.

[Travis Porter]

I still use pipe clamps a lot even though I have a fair amount of parallel clamps. Over tightening is an issue as others have suggested since it is so easy to do since you can torque them down.

For every two clamps below I try to have at minimum one clamp above alternating one above one under. Additionally, I use a straightedge across the top. Even if you don't overtighten, it is easy to "bow" the glue up and using a straight edge across your glue up you can see where it is bowed and adjust pressure accordingly.

My only other suggestion is after your initial tightening and before you use the straight edge is to take a hammer and a scrap block and tap your boards down flush to the pipe. Many times I have found the boards have raised off of the pipes and are no longer flat.

[Bas]

I bought a roll of cork with adhesive backing at a crafts store (Michaels). It's pretty thin, but sufficient to protect the wood from the clamp. I have a bunch of squares ready made, so it's easy to replace them when they wear. Clamp blocks work too of course, but self-sticking is convenient.