Fiberglass Question - Please Educate me !

[Van - E-Mail LIST]

For what it's worth Lance, the Saran Wrap worked like a CHAMP ! Just pulled the first two rings, and they look damn nice, if I do say so. . . . .

Thanks for all the input from everyone.
________________________________________________

Van Flowers
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www.rc-aerobatics.com




  ----- Original Message ----- 
  From: s.vannostrand at kodak.com 
  To: discussion at nsrca.org 
  Sent: Wednesday, September 11, 2002 12:48 PM
  Subject: Re: Fiberglass Question - Please Educate me !



  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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