I run on a very low budget...about 0 dollars... and I recently purchased an
estes fat boy and am troubled with the strength of the body tube they have
provided because this time i'm going to put 3 24 mm engines in the
rocket...i want to add strength but i don't know how to fiberglass a rocket
and i don't have any fiberglass. But i do have some finishing epoxy and 30
minute epoxy laying around and i was wondering if i coated the rocket body
tube with 30 minute epoxy and then wrapped a piece of copy machine paper (no
lines) around it...after that i would coat the whole thing with finishing
epoxy...would this process be efficient and would it add a good amount of
strength to the rocket?
You're probably better off (with the materials you want to use)
taking the "finishing" epoxy (this is a fairly thin, runny kind,
yes?) and using it as your laminating resin. The "30 minute" epoxy
is intended to be used as an adhesive to glue things together, and
would be so thick that it wouldn't work as well... you would have a
thick layer of epoxy that would add more weight than strength.
With the thin epoxy, try brushing as thin a layer as possible on the
tube, and then smoothing the paper down onto it, starting with one
edge along the tube lengthwise, and doing a thorough job of rubbing
it down onto the tube, so that the excess epoxy gets squeezed
out from under the paper as you go and no blobs are trapped underneath.
This will probably soak enough epoxy into the paper to make it look
saturated, but if you see any dry spots on the outside, apply a very
small amount more resin there - but not so much as to make a thick shiny
build-up on the surface.
Once it cures good and hard, sand with really fine aluminum oxide paper
(#320 or so) - smooth down any fuzz that the epoxy raised on the paper,
and feather the overlap edge if you want - but don't sand away the paper
otherwise, just a light uniform "kiss" sanding over the surface.
At any rate, that's what I'd do for a first try with the specific
materials you mention. Your mileage may vary... I've never laminated
with copier paper and epoxy before, so I'm just giving my best guess
based on how I'd want to modify the techniques I'd usually use with
thicker, more porous materials such as glass cloth or carbon tissue.
The Estes FatBoy needs no strengthing, it is a very tough kit as is. I have
two of them, one with a 3x18 cluster, and the other with a 3x24. I have
crashed them both several times. (burnt shockcords, melted parachutes) You
just go pick 'em up, dust 'em off and fly 'em again.
NAR 82797 L2
Try scuffing up the finish and using thinned wood glue with the copy paper.
Used it plenty of times with wrapping paper tubes. Strong enough to be used
with 12 foot superrocs. Not much added weight either. But, you won't need
it for a 3x24mm model. I'm one of those wood glue and balsa is fine for
mid-power mach flights.
Vishal, Joe's advice is very good. Don't bother with strengthening the
tube. The estes tubes are alot stronger than you might think. If you
want to improve the Fatboy, I'd recommend getting a nomex chute
protector, perhaps lengthen the shock cord, & get a nylon chute. DR
Laminating takes a little practice to achieve good results, especially
on an exterior surface. Try it on some scrap first. Even paper will tend
to "unroll" from thin (finish) epoxy, so you need to get a "feel" for
when the tackiness of the epoxy is sufficient to keep the paper in
contact with the tube.
You might want to "dry fit" the model together and see if an internal
layer of paper or tagboard might do the job for you. You can pre-roll
the paper and cut it to fit the inside of the body tube where you want
to add strength. Like adding extra couplers. Cosmetic mistakes won't be
so critical on the inside. A little, thin ballon can be blown up inside
the tube to hold the paper against the inside wall while the epoxy dries.
I think your Fat Boy will be okay, though, without any laminations. The
body tube is fairly short and it makes a sturdy rocket when completed.
For a 3 x 24mm cluster, I would recommend beefing up the inside
of the BT, rather than worrying about the outside. The ejection charges
from 3 "D" motors will create a lot of heat and likely toast the BT and
shock cord. I recommend epoxying the inside of the BT, and using a
Nomex shock cord protector, or a shock cord made of braided Kevlar,
if you want your recovery system to withstand more than one or two flights.
Note - do not apply epoxy too thick, to the top inside of the BT, or
your nose cone will not fit.
I read an article or posting somewhere that suggested using nylon stockings
as a reinforcing material - instead of fibreglass cloth. I just might give
that a try.... hey Jerry, can I borrow a couple of pair of your pantyhose to
try it with?
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