----- Original Message -----
Sent: Saturday, May 22, 2004 2:27
PM
Subject: [FlyRotary] Re: Fiberglass
Help!
Ed,
Having built A Cozy, I learned a couple thing about fiberglass.
First of all for complex curves, you need to use BID cloth, It will flex
and contour to most shapes. Also, I would definitely use the BID from a
roll (like fabric), and definitely not BID tape, which has a bound edge.
Also cut the selvedge edge off of the BID cloth. If you have any areas
that have excess BID, just cut a dart in it, to remove the excess cloth.
Try to get the excess on the next layer in a different spot if
possible.
Keep
you epoxy warm. Heat it with a lamp, if you're doing it in the
morning. I used MGS, and loved it. It is thin, wets out good, and
has a very high TG ratio.
If
you have another epoxy already, just warm it up to get it thin, and brush it
on sparingly. You want it to wet out, but definitely not running
off. Brush it on, and then hit any white spots with a little
more.
If
you're doing 3 layers, wet in your first two, but when you put on the 3rd,
don't add any more epoxy. Stipple it with the brush. Using a hair
dryer will help pull the epoxy up the the new layer. If you have any
white spots left that just won't wet out. Use just a dab of
epoxy.
My
.02
Steve Brooks
Ok, you fiberglass types. I need some
guidance. I can (and have) slapped resin on glass cloth
and obtained a functional (if heavy) item. However, I am about to
start work on my new radiator ducts and I would like to
do better. My ducts will be approx. 4"x4" at the inlet and
approx. 9"x10" at the core. There might be as much as 1 psi pressure
on the walls (if I should ever be so lucky to go that fast).
There a some semi compound curves at the
corners of the duct as it slopes inward from the top and bottom from the
core to the inlet.
I need your recommendation about the weight and
weave of the cloth. I have previously used the cloth tape as it was
easy to manage, but it required several layers and it is a bit heavy.
Like I said functional but not pretty nor light.
I would like your guidance on how best to apply
the sheet to the mold. In the past, I basically wrap the foam mold in
duct tape and the lay resin on it followed by raps of the cloth tape and
more resine. I am told that using sheet rather than the tape and first
laying it out on aluminum foil to wet it and then cut it in sizes say to fit
a side of the 4 side foam mold with a bit for overlap with the adjacent
sides was one way to go.
Any suggestions would be
appreciated.
Ed
Ed Anderson
RV-6A N494BW Rotary
Powered
Matthews, NC