I don't know about that, Andy. They seem to apply quite a bit of pressure. I cut a pretty narrow piece out for the slot and can barely get them to expand enough to slip over the boat and gunnel. (Of course, I'm not very strong either.) I actually think I may need to cut the slit a little wider for fear they will squeeze out too much thickened epoxy. In this case, the gunnels are lying down against the wall of the canoe pretty well without much force needed except in a very few places, so maybe we're both right - this is an application where not much force is needed. I'm using 2" white pvc pipe if that makes a difference.

Patsy
: I used an ordinary hacksaw, or, for smaller pipe sizes, my bandsaw
: with a toothy blade (24 tpi, I think) designed for metal/plastic.

: These plastic clamps are great for holding things in place which don't
: require a great deal of force, but they exert a lot less pressure than
: a typical spring clamp. I find they work quite well in "squashed"
: mode
: where they are compressed down so the sides overlap and then inserted
: into a gap, so that they exert a pressure trying to expand back to full
: size - great for when your stripping is filling a hole, but not so
: useful for the application you describe. On the other hand - because they
: are very cheap - you may get good results simply through having a large
: number :-)

: I found some much thicker-walled tube lying around near some road works -
: yellow gas pipe offcuts - this stuff makes slightly stronger clamps than
: typical grey or black fall pipe or smaller drain pipe.

: Andy