Aluminum spars

[AaronS]

Jim,

Call Brion's shop for UHMW, or you can also try APS or Svendsen's, depending on which coast you're on. It's wonderful stuff, you'll find uses for it all over your boat. Since you're refurbishing your mast, you might see if you can get some wide (6" or greater) stuff for the front of your mast at deck level. Makes a great sacrificial layer to protect your new paint job from the likes of stainless rings or j-locks.

Aaron

[osteoderm]

In western Canada at least, there are several outlets of a place called "Industrial Plastics & Paints" that sells everything UHMW, Teflon, or otherwise hard-to-source in plastics, in every form from tapes to huge blocks. Ostensibly a wholesaler, they still sell to the general public in some locations.
Look for such an oufit in your own neck-o'-the-woods, or consider mail-ordering. i've used them before, and they provide generally great service, and usually end up being cheaper than buying specialty pre-packaged materials from chandleries.