I have toyed a bit with different ideas for fittings on my Iggy. As this kayak is a project of keeping everything simple and functional, I ended up with a decicion of using Maroske fittings. I have seen them described here, and seen warnings about tubing that was impossible to remove.

This is my way:
I made wooden archs to put between the deck and the tubing, to make sure the tubing had no way to get kinked. There is a groove in the arch, and it got painted with epoxy. This will be the inner surface of the fitting. I left those to dry, mounted them the next day, and drilled holes through the deck letting the arch guide the drillbit. That way everything ends up with a good fit.

Then I used a very thinwalled tube with a bungee threaded through.
As the bungee gets thinner when stretched there were no trouble of getting that out of the tube, and with an empty tube there was no trouble of removing that, as it stretches and releases from the fiberglass.

Hope this makes sense (or ill have to make a cartoon howto.)

Gennie
www.byg-kajak.dk