Mold Making for fiberglass fuselage.

[Bob]

I am looking for any books, articles or other information that will help
me to build a mold in which to cast a fiberglass fuselage, or boat hull.
I am interested in building a foam or balsa model and casting the mold
from that, however, I would like to be able to salvage the plug if
possible. Any help or ideas appreciated.

Bob Rains
Software Consultant
Academic Computing Services
Eastern Kentucky University
ACSR...@EKU.BITNET

[civi...@ucsvax.sdsu.edu]

>I am looking for any books, articles or other information that will help
>me to build a mold in which to cast a fiberglass fuselage, or boat hull.
>I am interested in building a foam or balsa model and casting the mold
>from that, however, I would like to be able to salvage the plug if
>possible. Any help or ideas appreciated.

I am very interested in this also. I have a friend who knows how to do
this, but the process he uses is quite complicated and expensive. I can't
even remember all the steps. He designed and builds the Tempests. A small
V-tailed glider. He mass produces these things for hobby stores in his
garage. That is the only way he can justify his process. There must be a
simpler way to do this. I was thinking about using a foam or balsa model
and casting the mold from this also. What material would you use for the
mold? Salvaging the plug shouldn't be a problem if you coat it with resin
or something to make it non-porous and then spray it with plenty mold release
agent such as silicone spray. What do you think? I am experimenting with
foam and glass wings right now and would like to get into composite
fuselages as well. Do you (or anyone else) know of any difference in
strength between polyester or epoxy resin? Clearly, polyester cannot be
used on foam, but I would like to be able to make the fuselage and other
parts that will not cover foam out of polyester resin because polyester is
significantly less expensive than epoxy. However, it seems like most
fuselages I see are made out of epoxy resin.

;-----------------------------------------------------------
; Tracy R. Reed |
; SDSU |
; CIVI...@ucsvax.sdsu.edu |
;-----------------------------------------------------------

[Michael Matthew Guslick]

I recently checked out a book at a library that had a chapter on making
fiberglass bodies from molds. I belive it's called _Using Composites in
Model Aircraft_ or something like that. I think I still have it checked
out, and I'll try and get the real title and author to post (unless someone
wants to save me the trouble!)

-------------------------------------------------------------------------------
Mike Guslick / ^ \ USnail: 711 Hwy. C
NAR #53962 ---(.)==<-.->==(.)--- Grafton, WI 53024
mich...@csd4.csd.uwm.edu SR-71 Blackbird ph.: (414) 377-4428
-------------------------------------------------------------------------------
"Opinions expressed herein are my own, but I can lease them to you............"

[Rod Don]

I believe that polyester resin is less tough - hence more prone to
cracking in the high vibration environment of an R/C aircraft...

[Thomas Taylor]

Two things.....

I understand that SIlicone and fibreglass do not like each other. Your mould
release and release wax should have NO silicone in them.

2nd, Polyester resin is far more dangerous to work with then epoxy, One drop in
an eye, and say bye bye to the eye. Of course you don't want epoxy in your eye
iether...... And polyester resin STINKS TO HIGH HEAVEN. This stuff has lead to
divorce when used at home.

Of course, use all the safety equipment when using these products, goggles,
filter mask (NIOSH t23C i think), gloves, proper ventilation, etc

[Michael Matthew Guslick]

Here's a piece of e-mail sent to me on the subject (I hope you don't mindme
posting it here, stefan)

From SBI...@NAUVAX.UCC.NAU.EDU Wed Sep 22 12:13:26 1993
Received: by csd4.csd.uwm.edu; id AA13120; Wed, 22 Sep 93 12:13:24 -0500
Received: from NAUVAX.UCC.NAU.EDU by NAUVAX.UCC.NAU.EDU (PMDF V4.2-12 #2384) id
<01H38U554...@NAUVAX.UCC.NAU.EDU>; Wed, 22 Sep 1993 10:11:00 MST
Date: Wed, 22 Sep 1993 10:11:00 -0700 (MST)
From: STEFAN <SBI...@NAUVAX.UCC.NAU.EDU>
Subject: Mold Making
To: mich...@csd4.csd.uwm.edu
Message-Id: <01H38U554...@NAUVAX.UCC.NAU.EDU>
X-Vms-To: IN%"mich...@csd4.csd.uwm.edu"
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Content-Transfer-Encoding: 7BIT
Status: OR

I have the same interest in making my own molds. There is a book outhere
the title is "Do it yourself Vacuum Forming". The book can be purchesed
from the RCM model magazine and it is about $9. The guy that publised
the book used the regular house vacum cleaner to setup his mold desk. It seems
preatty simple to me. It is a brand new book and the authore is Douglas E.
Walsh.

I hope this information will help you. I think you can find the book in the
past two edition (September and October only) of the RCM Modeler.

[Ross Klippert]

---

I have worked with a friend to make molds for glass/composite
boat parts. Once you get the "plug" made, be sure to seal it and
most importantly, make it smooth. In fact, polished is actually the best route.

Use a mold release, such as PVA (available from fiberglass specialty shops).
Then use resin and fiberglass mat to make a negative from your plug. If
your part is one that can be removed from a 1 piece mold, you should be able to
separate the mold by disolving the PVA with water.

We have found that the poly-resin seems to be much more brittle than the epoxy
resins. We made identical boats from carbon-fiber/poly-resin and
glass mat/epoxy. The glass boats are doing fine, the carbon-fiber has since
been shattered from impact.

Good luck.
------------------------------------------------------------------
Ross Klippert |
Motorola GSTG | This Space for Rent...
Scottsdale, AZ |
ro...@cso.geg.mot.com |
___________________________________________________________________

[Kim M Sjodahl]

I'd appreciate if you could post me a copy of your ansears!
Kim Sjoedahl, CTH
m93...@mtek.chalmers.se

[Colin Watters]

I have some experience with fiberglass moulds and epoxy mouldings but
I am still not happy with the release agents I use. Has anyone used
a better method...

The only way I can stop the laminate sticking is to coat the mould with
wax and then spray on PVA release agent (You have to spray the PVA on
very 'dry' otherwise you get a sort of water-on-wax effect). This works
well except that the PVA and wax gives the mould and resulting laminate
a matt finish even though the mould is polished. I tried wax on its own
and trashed a mould trying to get the laminate out.

Another problem is gel coats. I can get polyester pigment and gel coat
easily for mould making but where do you get epoxy resin pigment and
gel coat?

Colin.