Anyone know how or if Irwin Quick Grip clamps can be adjusted or restored to
fix them from slipping when pulling the handle/trigger to tighten the clamp?

I've got quite a few and they are becoming very frustrating. I know they
have a life time warranty and I have already taken 3 or 4 back for exchange,
but this is getting old fast, I'm about to pitch em in the trash.

I read an advertisement about Jorgensens similar clamp saying they have 40%
more gripping power and that they don't slip. Anyone have any experience
with the Jorgensen quick clamps?

Thanks,

Paul