composite fins without vacuum bagging?

Is there a good way to lay up carbon fiber over a light weight core without
the benefit of vacuum bagging? (assume flat fin profile). Thanks. I seem
to remember someone once mentioning wax paper or plain glass panes with
weight on it.
Koen
Reply to
Koen O. Loeven
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I've done it by using a mylar sheet on top of the composite and a bag full of sand on top of that. It seemed to work out pretty well.
Chris
Reply to
Chris Eilbeck
I came across this page a while ago, they used a hydralic press, but clamps or other weight sources should work:
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Reply to
John Bowles
koen:
you can use wax paper between glass (or metal plates) or use mylar between glass or metal plates... I have also used sandbags....
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shockie B)
Reply to
shockwaveriderz
You can press it between two sheets of glass or smooth plywood, with heavy weight evenly distributed over the top. Use wax paper or mylar between the resin and the glass. If you use wax paper, use two layers because the resin tends to get through tiny pinholes in the paper.
Reply to
raydunakin
I pretty much use the same methods as the other posts.
Weighted bags or books to compress sandwich.. I tried glassing a fin set a few yrs back.....sandwiched fins between 2 thick sheets of glass and left to cure..... Weighted bags or books to compress...
Lets just say that my fins snapped and I thru a tantrum when I tried to separate them from the glass sheets without a release layer........
*** Use wax paper, Food Cling Wrap, Clear sticky plastic you cover books with (Stuck to the Glass) or some other release ***
Reply to
CJC
Just be careful -- many materials can stick to the epoxy more than you'd expect, and be a RPITA to remove.
Haze them (your cheapo release) lightly with a paste wax first, and they come off MUCH more easily. Only takes a minute or two longer to do it.
-Kevin
Reply to
Kevin Trojanowski
Shrink Wrap. Even rergular Saran Wrap will shrink tight when heated a bit.
Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!
Reply to
Bob Kaplow
What guage mylar did you use??
RDH8
Reply to
Robert DeHate
It was about 0.5mm thick. Not sure what that equates to, got it from a mate who does composites repairs on aircraft. I just laid up the carbon on the mylar as a patch and applied it across the fins and body tube in one go.
Chris
Reply to
Chris Eilbeck
I've used mylar (forget the thickness, probably .005 in. or so) sprayed lightly with silicone release spray for fin laminations... apply cloth and resin to fin panels, sandwich between sprayed mylar sheets, stack between a pair of sheets of 1/8" G-10, stand weights on top, allow to cure.
-dave w
Reply to
David Weinshenker
sprayed
Did you have any trouble getting the paint to adhere to the finished product, due to residue from the silicone spray?
l
Reply to
raydunakin
I can't tell you one way or the other - the fins in question were installed "naked", without painting. (I did a bit of local sanding to prepare the surface for gluing.)
-dave w
Reply to
David Weinshenker
Wow, thats thick.
RDH8
Reply to
Robert DeHate
Yep. It gave really nice curves over the fillet, only a couple of tiny spots to fill in afterwards.
Chris
Reply to
Chris Eilbeck

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