Is this fiberglass? I was planning to do the Sonotube/fiberglass route for my next scope; it seems perfect; low weight, very strong, etc. If what you're talking about isn't fiberglass, I'd be very curious to know what it is!
BTW - did anyone see in S&T's ATM column recently, that wood and fiberglass scope that some woodworking type made? It was beautiful; with some carefully chosen laminate, and inlaid detailing & all that. He made his tube out of laminate and fiberglass resin.
I was going to solve the cooling time problem by putting vents in the bottom, and putting a small fan at the upper end, mounted in a disk that fits snugly in the tube. If I put in an eyepiece or a 35mm film cannister, then the only entry points to the tube should be thru the vents or thru the fan. So - click the fan on, and the scope should be cooled inside of an hour.
On a different topic: did anyone catch that post to sci.astro.amateur about building your own barlow? I went to a camera store, and bought a used 2X teleconverter for $5, then picked up some PVC parts that should hold everything together. Today or tomorrow, I'll lathe 'em into something that should work. We'll see what happens! The only drawback is that the clear apeture of the lens is about 21 or 22mm - a bit small for 1.25 inch eyepieces, tho it would be perfect for .965.
-Dave