The bolts are covered with clear polybutylene tubing

Dan's Speaker Cans

The bolts are covered with clear polybutylene tubing. I also put black electrical tape around the tower so the threaded part of the U-bolts wouldn't scratch when I pushed them over. Some simple green made it nice and slippery, both to get the tubes on the bolts, and to get the bolts in place on the tower.

I bought all the parts at Lowe's, except the PVC pipe itself, and the terminals.. I found a PVC pipe scrap to work for that. As it states in the article on your DIY site, you only need about 18". The terminals came from Radio Shack.

Yeah I have been meaning to post something on WakeWorld, but I just haven't gotten around to it yet :-p I wanted to make sure you got the link though, since your DIY site was such a good resource for the speaker cans. I plan to paint them black at some point, but I need to find some paint made specially for plastic - I'm afraid if I just spray paint them the paint will flake off the smooth surface, and I really don't want to have to scuff-sand them if I can find a paint that will bond with plastic well.

Below are sample photo's from Dan's Project and you can view all his photos at http://members.tccoa.com/texastbird/Monster/Speakers/