Clamps

[krich]

Anyone have an opinion on clamps. I relatively new to woodworking and only have few clamps right now. After a little checking, there appears to all types (screw clamps, quick clamps, pipe clamps, etc) and a multitude of manufactures. I currently have 4 Craftsman quick clamps and several pipe clamps. I’ve only used the quick clamps and they seem to work pretty good. The face of the pipe clamps do not remain parallel when I tighten them down. This makes them pretty much useless when trying to glue up a panel. Would appreciate some opinions on types and manufactures. I prefer to buy the better quality equipment/tools; have found that it is less expensive in the long run by not having to replace as often.

Any thoughts?

[AMF]

Welcome krich! As for the clamps it all depends on the use. I have a variety of 3/4 and 1/2" pipe clamps in different lengths as well as quick adjust "f" clamps and of course a few spring clamps and c-clamps. I use my bar clamps for just about everything. For anything other than rough glue ups I have hardwood blocks that I use to distribute the pressure from the clamps to the surface. The f-clamps are good for dry fitting and the like but dont have enough pressure in most cases.
Bar clamps are the most economical and using a "bessey" clamp is getting pretty pricey, but they are good for carcas assembly and anything that needs to be held square.

Alex

[jcclark]

3/4" pipe clamp are all I have used for the past 35 yrs.
Never had any problems with panels, but I do alternate
them on top and bottom of the panel.

[Don]

As for bar clamps, JC has it. I've used the pipe clamps for many years and I'll attest that even the more expensive clamps will bow under pressure, you will always need to alternate, except for very light work. Don't bother with the 1/2" pipe clamps, 3/4" will satisfy just about any need.

Nice picture, JC, thanks for posting.

dawjr

[krich]

The pipe clamps I have are ¾”. The problem I’ve experienced is that the two faces of the clamps do not stay parallel when tightening. After looking at jcclarks picture, I think the lack of parallelism between the clamp faces would cancel out. It may also be the clamps I’m using, they are the HF brand. Appreciate the info, I’ll do a quick setup and see if alternating them top and bottom will cancel out the problem.

[jcclark]

It will cancel it out.

I even lay a straight edge on the boards and tighten alternating clamps to
make a flat surface.
You can actually see and adjust the "bow" as you tighten if you
tighten the top and bottom and monitor the flatness.

Also, a much overlooked reason.
When joining the edges of the boards, keep track of which face
is against the jointer fence. Try to alternate them.
The jointing is never dead on 90 deg. so the angle can accumalate
if all the faces of the boards are the same orientation.
I mark an "x" on the face against the fence and try to alternate
them when glueing up. (hope that makes sense)

[krich]

Originally Posted by jcclark

Also, a much overlooked reason.
When joining the edges of the boards, keep track of which face
is against the jointer fence. Try to alternate them.
The jointing is never dead on 90 deg. so the angle can accumalate
if all the faces of the boards are the same orientation.
I mark an "x" on the face against the fence and try to alternate
them when glueing up. (hope that makes sense)

Actually that does make a lot of sense. It's something I really never gave much thought, always figured the jointer was pretty accurate but your right, it's highly unlikely it is perfectly aligned. Learned something new, that's why I like these forums. Appreciate the info!!

[Don]

I'll throw out another thought. As JC stated, alternate the jointed face, but also pay attention to the "face" of the wood, i.e. alternate these as well when gluing for width, such as a tabletop or other. The "face" of the wood is the outside of the tree as determined by the anular rings, wood tends to cup toward the inside of the tree. By alternating these as well, you cancel that tendency out.

All the best, Don

[Don]

Originally Posted by krich

The pipe clamps I have are ¾”. The problem I’ve experienced is that the two faces of the clamps do not stay parallel when tightening. After looking at jcclarks picture, I think the lack of parallelism between the clamp faces would cancel out. It may also be the clamps I’m using, they are the HF brand. Appreciate the info, I’ll do a quick setup and see if alternating them top and bottom will cancel out the problem.

And yet another rambling. Your note about the clamp faces can be overcome to some degree by "laying" over the clamp a few degrees. The object here is to get the center of the screw about in the center of the material thickness. This problem is usually not an issue with alternating clamps and spoil material on the edges, such as in JC's picture.

All the best, Don

[jcclark]

Originally Posted by Don

alternate the jointed face, but also pay attention to the "face" of the wood, i.e. alternate these as well when gluing for width, such as a tabletop or other. The "face" of the wood is the outside of the tree as determined by the anular rings, wood tends to cup toward the inside of the tree. By alternating these as well, you cancel that tendency out.

All the best, Don

Good point Don,
I always try to do that too.