You've had many good suggestions for dealing with the shrinkage of the
glass-epoxy laminate. Here's one more.

With a tablesaw, cut one lengthwise slit in the pipe and cover the slit with
packing tape.
Wax the pipe thoroughly and do your layup. Bond a couple of blocks or other
attachment points to one end the part.
Twisting the pipe vs. the part should break the bond between the pipe and
the part.
Drill the other end of the pipe for some attachment and pull the part from
the pipe with a come-along.

"Garland Gray II" wrote in message
...
If I were to wax the outside of a piece of 2 1/2 inch pvc pipe about 6
feet long, and then lay up several layers of fiberglass and epoxy, would
the resulting tube slide off the pvc easily enough after curing ? Or would
I need to first wrap the pipe with sheet plastic or similar ?
Thanks !

On Thu, 10 Jan 2008 10:59:46 -0500, "Conlin"
wrote:

You've had many good suggestions for dealing with the shrinkage of the
glass-epoxy laminate. Here's one more.

With a tablesaw, cut one lengthwise slit in the pipe and cover the slit with
... tape.

Make that a long straight diagonal (shallow taper) cut, and success is
pretty certain, I'd think....

Brian Whatcott Altus OK

I can't see what benefit there would be to the slit being diagonal or
tapered and it'd be a tricky cut to make. The important thing is that the
pipe be able to contract a bit after the laminate has cured.

A couple of other possibilities:
Coat the pipe with a thin (maybe .020") coating of paraffin wax and melt the
paraffin out after the laminate's cured.
If using a core of styrofoam (with packing tape finish), the core can be
mechanically destroyed after the cure.

"Brian Whatcott" wrote in message
...
On Thu, 10 Jan 2008 10:59:46 -0500, "Conlin"
wrote:

You've had many good suggestions for dealing with the shrinkage of the
glass-epoxy laminate. Here's one more.

With a tablesaw, cut one lengthwise slit in the pipe and cover the slit
with
... tape.

Make that a long straight diagonal (shallow taper) cut, and success is
pretty certain, I'd think....

Brian Whatcott Altus OK