long clamps

[petar73]

Hi, I need some at least 2m long clamps. Most of my clamps are bessey, the longest revo I have are 1.5m, but I am looking for cheaper alternative. I have a couple of bessey 3/4 pipe clamps, but they are not strong enough for hard wood at that length.
The clamps I am considering are Bacho F-Clamps with Steel T-Handle. They look identical to Piher mod. R – dept 15cm clamps and are less expensive but I have no experience with either of them so looking for advice. Thank you.

 

[Birdhunter]

I bit the bullet and bought Bessey long clamps. I clamp up some real long stuff and the Bessey clamps are flawless. I've had some for over 20 years and they are still perfect.

 

[hdv]

If you already own Bessey Revo's, couldn't you use the Bessey K Body Extender to connect two together to get to the length you need? That seems to me to be the cheapest solution. I use them in such cases as yours and never had any trouble with them.

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[petar73]

If you already own Bessey Revo's, couldn't you use the Bessey K Body Extender to connect two together to get to the length you need? That seems to me to be the cheapest solution. I use them in such cases as yours and never had any trouble with them.

[attachimg=1]

I thought about the extenders, but I only have 20 revos and often need the 1m and 1.5m in addition with longer lengths so would prefer to get at least 4 clamps over 2m.

I bit the bullet and bought Bessey long clamps. I clamp up some real long stuff and the Bessey clamps are flawless. I've had some for over 20 years and they are still perfect.

Probably getting more revos is my best bet, but I was wondering what else is out there.

Thank you both for your thoughts.

 

[rvieceli]

I have found that the Bessey Revos just work better than anything else. Bessey makes an 82 inch (2.08 meter) and a 98 inch (2.49 meter)capacity REVO clamp.

Over in the US the KRE3582 is around 75-100USD KRE3598 about 140USD

The length may mean some extra shipping charges.

Ron

 

[guybo]

Hi, check out the kre varios, and with extra jaws multiples can be clamped on same clamp. A bit pricey. guy

 

[Crazyraceguy]

For exactly the same reason, I just bit the bullet and got the 98" Besseys. I've got 2 of the standard Revo and 2 of the Revo-Vario in 98", 2 of the 78" Revo, 2 of the 60" Vario, 4 50" and I'm not even sure of the smaller ones off the top of my head and a couple of the extenders, but I'm in a big commercial shop. My needs are way different than most though, there are times when I use them all at once.
As a hobbyist it might be hard to justify, but then again, how many would ever need them? Especially more than once? Lots of things would be great to have in certain situations, but often enough?
It's tough to have thousands of dollars worth of tools that are just sitting idle. I know there is a percentage of people who buy things for "one job" and sell them off after, but that seems like a false economy?

 

[CeeJay]

I’ve used long pipe clamps by coupling 3/4 pipes together to get 2m plus clamps, using Rockler clamps.

I’ve found these very strong - interested why you think they would not be strong enough?

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[Michael Kellough]

Pipe clamps are plenty strong but all long clamps bend and the jaws are no longer parallel, especially pipe clamps.

This can be a problem with thicker glue ups but can be mitigated by using a simple pad/caul that redirects the pressure to the middle of the stock.

Use half round hardwood molding (ideally the same thickness as the stock) and tape it to the edge of the glue-up. Buy or make or rip a dowel in two.

Even when the clamp jaws rotate around the caul as the bar bends the pressure will still be concentrated on the middle of the stock instead of the side the clamp is on.

When a long clamp is tightened the bar will bow towards the stock. Don’t give in to the temptation to put a block to wood under the bar because there might be enough pressure to bend the glue-up. Instead just move the clamp farther from the surface. This might increase the non-parallelism of the jaws but with the half round caul it won’t matter.

 

[Bob D.]

"Use half round hardwood molding (ideally the same thickness as the stock) and tape it to the edge of the glue-up. Buy or make or rip a dowel in two."

This sounds like a good 3d print project. Make some tool free, snap on pads that will concentrate the clamping force as you describe.

 

[CeeJay]

Make them with an embedded magnet in them so they attach direct to the clamp face and you’ve got a winning product.

Having said that the pad rotation is pretty minimal in long clamps - maybe 1 or 2 degrees max. Not enough to be a problem in my experience.

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[petar73]

For me pipe clamps are good for joinery, but lack clamping force for gluing hard wood work tops or such compare to revos, also I would prefer deeper throat and for that I do not want to invest in more pipe clamps.  Thank you everyone.

 

[mino]

For me pipe clamps are good for joinery, but lack clamping force for gluing hard wood work tops or such compare to revos, also I would prefer deeper throat and for that I do not want to invest in more pipe clamps.  Thank you everyone.

Pipe clamps can have more force - as much as I-profile ones and actually more as they do not have stability problems at great lenghts. You just need a bigger diameter tube.

The problem is you will likely need to make such clamps yourself, or have them made at a local metal shop..

 

[Bob D.]

"The problem is you will likely need to make such clamps yourself, or have them made at a local metal shop.."

Are there pipe clamp sizes other than 1/2" and 3/4", I have not come across any. But if you want stiffer bar sections you can use 1" pipe at whatever length you need plus a couple 1x3/4 reducing couplings and a short piece of 3/4 at each end to mount the pipe clamp ends on. This might reduce the reach of the clamp a little which is already limited for many applications.

 

[CeeJay]

Yes 1” pipe clamps are available.

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[mino]

"The problem is you will likely need to make such clamps yourself, or have them made at a local metal shop.."

Are there pipe clamp sizes other than 1/2" and 3/4", I have not come across any. But if you want stiffer bar sections you can use 1" pipe at whatever length you need plus a couple 1x3/4 reducing couplings and a short piece of 3/4 at each end to mount the pipe clamp ends on. This might reduce the reach of the clamp a little which is already limited for many applications.

I was thinking of the 1.5" and more when talking of bigger diameters for more force.

1" is the bare minimum for a long clamp, in my view.

 

[Steve1]

If you already have 3/4" pipe clamps, you may wish to try this. 
Should be possible to mount 2 sets of clamps to one pipe.  One set facing down to clamp your workpiece, and one set facing up to clamp a scrap piece of wood or pipe.  The idea being to achieve a net bending stress on the pipe as zero.
Sorry about the bad sketch, but I expect you get the idea.

 

[ChuckM]

Not sure about your exact project or object to be clamped. Well-cut joints don't need a huge amount of clamping force after being properly dry-fit and tested.

Here're a coupe of ideas found on the internet.

I've used a frame/wedge system (shop-made wedges on one end) for a long glue-up...but unfortunately can't find the photo.

I do have four very long Bessey clamps...hardly used since last project -- five years ago? They were used last year, when on loan to my neighbor. [embarassed]

 

[Michael Kellough]

“ Well-cut joints don't need a huge amount of clamping force after being properly dry-fit and tested.”

In that case band clamps will work.

 

[Bob D.]

I was thinking of the 1.5" and more when talking of bigger diameters for more force.

1" is the bare minimum for a long clamp, in my view.
[/quote]

How long is 'long'? Four, six, eight feet or more?

I don't think diameter makes any difference with regard to force applied to the work. The pipe is in tension and the workpiece is in compression, you will not cause the pipe to fail. You might deform/flex when you tighten the screw if you apply enough force, but it will not break.

So yes 1" and larger diameter pipe will resist flexing to some degree more than the normal 1/2 or 3/4 pipe commonly used. But the amount of force generated by the clamp comes from the clamp, not the pipe diameter the way I see it. All the larger pipe will do is increase resistance to the jaws faces moving out of parallel, which they never were perfect to begin with and no manufacturer ever claimed to maintain parallel as far as I know.

To me pipe clamps are for rough work. If the jaws remain parallel is not an issue for where and when I would use them. So worrying about the pipe flexing if I crank down hard on the clamp screw does not concern me. Increasing the diameter of the pipe just adds to the weight of the clamp and makes them harder to handle.