Fiberglass Question - Please Educate me !

[s.vannostrand at kodak.com]

Van, in after the car wax, apply some PVA.  YOu can buy this at craft 
stores in small quantities near where they sell plaster/molding 
resing/etc.  Michael's and HobbyLobby are in Dallas.  Apply two coats of 
PVA.  From a sprayer if you can.  If you don't have air equip, buy a 
Precor can ($3) or use an old atomizer.  PVA dissolves in water so after 
laying up the parts, you can soak the mold/part in warm water and make it 
easier to remove.  Gray's right on the difficulty here.  YOu wouldn't 
belive the trouble we've had in making our own carbon mufflers. 

Another idea I have, but haven't tried, is to wrap the PVC molding pipe 
with Saran wrap, lay up the part, remove the pipe and then peel off the 
Saran wrap from the inside.  THis would be very easy.

--Lance


Van 

Use the coupler, it will be much easier to release. Apply 4 coats of real 
car wax to the coupler, this will release. There are better releases but 
you will have to buy a pretty big quantity. The real problem here is no 
matter what the release, the physical configuration you are molding is by 
far the hardest to get off the mold. The best way to remove a molded ring 
on a male mold is to push it off. This requires something that will push 
the inside (such as a piece of pvc pipe) while something hold the outside 
ring on a arbor press or similar. Hammering does not work real well. You 
may be able to glue in the pipe to  the coupler, then use something like 
and oil filter wrench to twist the ring off. 
It will have the natural spring back you desire.
 Carbon fiber will work just like the fiberglass other than the fact it 
will be 3X stiffer.  Check www.cstsales.com for carbon fiber and other stuff.
 

Gray Fowler
 Principal Chemical Engineer
 Composites Engineering 




Gray / Lance / All, 
 
I need to know what type of epoxy and release agent ( if I need that ) to 
get to make some fiberglass rings. Let me describe what I am trying to 
make, and tell me if I am totally off base here, and what I need to do to 
accomplish my task, if you can. 
 
I need to make about "6" Fiberglass rings. They need to be 4" in diameter, 
and about 2" wide. I have some 2" wide fiberglass cloth that is fairly 
heavy, and I plan to use that for the material. When they dry, I need to 
be able to make cut in them, so the ring can be spread open, and the ring 
needs to have some "spring back" to it, just slightly, so it needs to be 
sorta stiff. 
 
I have found that a 3 1/2" PVC coupler is a perfect side for the ring if I 
wrap the material on the outside. So is a glass Miracle Whip jar ( ;-) - 
Hey guys, I'm not a glass guru, but I do have a degree in MacGyver ! ) 
 
Can I put release agent on the coupler, or the far, wrap my glass on this, 
and will it work ? 
 
What working time epoxy do I need ? 
Would Carbon Fiber Tape be better ? 
Where should I get it ? 
How much is a round trip ticket to your workshop so you can teach me ??? < 
bigger grin > 
 
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