Prop,
Jack sat on my couch this afternoon and was trying to pry from my lips the name of this elusive knot. After questioning him it turns out that what he was trying to describe was not really a knot at all, but rather a wrapping technique used in flyrod/fishing rod building. (Attaching the line guides to the rod blank as well as producing an asthetically pleasing transition to the ferule at the joining ends of the rod blank.) To his credit it would strengthen the carbon tube, but since it required that the material pass underneath itself it would not be in as close contact with the carbon fiber tube as if you simply wrapped it, as I previously mentioned.

You can gauge for yourself the cleavability of the carbon tubing, by taking a scrap of it and splitting it with an knife blade. Although it makes sense to create the tube by alternating the direction of helically laid carbon fibers, this turns out not to be the case in the carbon tube I've used. All of it has been laid down parallel to the length of the tube....ridiculously weak for some applications. I still haven't figured out the genius behind that decision with regards to using it in the hobby industry. It should also be mentioned that carbon fiber should be cut with a high speed cutoff wheel to ensure the integrity of the ends, which are the most vulnerable to the initiation of splitting. I did exactly what you did, only I wrapped the ends and CA'd them with fantastic results. I hope this is of some help. As with all things...technology doesn't always trasition well between applications, and by all means consider this one man's opinion.

Peace.

Downtrodden.