F Clamps losing their grip

[Moonsafari69]

Has anyone else had this same problem?

I bought a stack of Silverline F Clamps a year or so ago and one by one they seem to be losing their grip. By that I mean as I tighten them down the cast iron arm doesn't bed into the steel bar to lock it down.

Rather than buy 20+ new clamps has anyone found a way to fix this?

 

[Beau]

Sometimes putting some more serrations in bar works. I have also taped a thread into the front bottom edge of a clamp and then put a grub screw in. The thread of the screw bites on the bar and stops it slipping but not an easy job.

 

[Moonsafari69]

Sometimes putting some more serrations in bar works. I have also taped a thread into the front bottom edge of a clamp and then put a grub screw in. The thread of the screw bites on the bar and stops it slipping but not an easy job.

Thanks Beau, I will grab a file at the weekend in that case and run over the worst offending clamps to see if that improves things. Cheers.

 

[morturn]

I did have this happen on a Bessy clamp once, I think I may have over tightened it and elongated the oval hole.

 

[Beau]

Sometimes putting some more serrations in bar works. I have also taped a thread into the front bottom edge of a clamp and then put a grub screw in. The thread of the screw bites on the bar and stops it slipping but not an easy job.

Thanks Beau, I will grab a file at the weekend in that case and run over the worst offending clamps to see if that improves things. Cheers.

I should add this was not on a Silverline F clamp but another brand but think they all work in pretty much the same way.

 

[Moonsafari69]

I did have this happen on a Bessy clamp once.

Well my Silverlunes are no Bessy, but you could well be right about the overtightening. Maybe need to back off a little locking them down.
Hope the Bessy has recovered.

 

[toolsntat]

Might be on a hiding to nothing but give Silverline a call about it.
Nothing to loose :wink:
http://lufton-trading-estate.cylex-uk.c ... 33108.html

Andy

 

[Setch]

I've used a hacksaw to deepen the serrations on slippy clamps with good success. It's a boring task, but the clamps no longer slip

 

[AndyT]

We used to have a member on here who developed a wide range of jigs and clever ideas.
When he died, his widow decided to leave his posts in place, to continue to help woodworkers.

There's a list of them here which might use up an hour or more

the-wonderful-world-of-niki-s-jigs-t69824.html

And this is his method for fixing cheap clamps

viewtopic.php?t=10590&highlight=

 

[Moonsafari69]

I've used a hacksaw to deepen the serrations on slippy clamps with good success. It's a boring task, but the clamps no longer slip

Hi Setch, did you add serrations to both sides (inside & outside edge) of the steel bar?

 

[Moonsafari69]

We used to have a member on here who developed a wide range of jigs and clever ideas.
When he died, his widow decided to leave his posts in place, to continue to help woodworkers.

There's a list of them here which might use up an hour or more

the-wonderful-world-of-niki-s-jigs-t69824.html

And this is his method for fixing cheap clamps

viewtopic.php?t=10590&highlight=

Hi Andy,

Brilliant, thank you. This is just what I was looking for. I will have a trawl through the rest of his jigs/tips too if they are all this useful. Thanks again.

 

[Moonsafari69]

Might be on a hiding to nothing but give Silverline a call about it.
Nothing to loose :wink:
http://lufton-trading-estate.cylex-uk.c ... 33108.html

Andy

Hi Andy. Now I know it's a relatively easy fix (and a repeatable one) i'll save me the call to Silverline. Thanks for taking the time out to send the link though, appreciated.

 

[Setch]

Hi Setch, did you add serrations to both sides (inside & outside edge) of the steel bar?

IIRC I did both sides, on the basis that both sides were serrated originally.

 

[Des333]

Had this problem on some Record clamps, I tried all of the above and more, it worked for a while but found I'd clamp joint up to find later it had loosened off and slipped. Contacted Record but got no reply, for a premium make! these lasted no time at all. I'm replacing F clamps with sash or G clamps.