One other hint for wrapping a tube with uni-directional on an angle.
Multiply the OD of the tube by 3.14 to get the circumference and then by the
sign of the angle you want. For example for your 2.5" tube, the
circumference is 7.85". The sign of 45 degrees is .707 so cut strips of uni
about 5.5" wide. If you keep the edge of each turn next to the previous one
you will have a 45 degree angle.
Again, pull it very tight if you are vacuum bagging.
--
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
"Glenn Ashmore" wrote in message
...
One solution that I have tried on a smaller scale. Slit the PVC pipe down
one side on a table saw. The pipe should close up a little so the kerf
will be a little less than 1/8". Cut a strip of 3/16 or maybe 1/4"
polyethylene
sheet maybe 1/2" wide and fit it in the kerf so that the edge is flush
with the pipe's outer diameter. That will expand the pipe over it's
normal diameter. Wax everything and spray on a couple of coats of PVA mold
release. Mist coat first then a fill coat.
Wrap your glass. If it is uni-directional, diagonally in both directions
then straight once or twice then a top ply of woven on the bias. If you
are vacuum bagging you have to pull all the diagonal and bias plies TIGHT
and tape them well or the fiber will bunch up as the bag pulls it down.
Once it is set up, knock out the poly strip out of the kerf and whack the
outside of the tube lightly to break the release agent and let some air
in. The pipe will spring back to its original diameter and drop out. If
it still sticks soak it in water to dissolve the PVA.
--
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
"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 !