I am not sure you exactly grasp the forces that act on boats at sea. About
the only thing that would make ABS pipe strong enough to stand up as a
Bimini frame would be a stainless tube on the outside. :-) Same is true
for that copper tube support on your windvane. One good quartering wave and
it will collapse against the transom. Most of the failures of commercial
stering vanes are in the stainless support structure. 316 Stainless has a
tensile strength of about 580 Mpa while hard drawn copper tube is under 200
Mpa. Heating to assemble it will soften it even further so soldered copper
tube doesn't stand a chance.

Same with the Bimini. The bending forces in tubing is all in the outer
fiber. Nothing you put inside (other than a steel tube) that will help
much. One good blow or an accidental steadying grab and it will be headed
for the recycling yard.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Mic" wrote in message
...
I am looking for any suggestions for a material that can be used to
fill the void in a PVC or ABS tubing, if and when used as tubing for a
bimini or the like. What size would you recommend?

Some thoughts include: epoxy, liquid foam, (cement -concrete???).....

Also what about using braided cable as a sort of rebar in the tubing
before filling tubing void?

Also what about using 3/4 or 1 inch copper tubing for a bimini or
dodger (plumbing supplies) with same tech. as above.


Thanks in advance.