Only partly on topic

[LCT Paintball]

I've got a project I'm building that I would like a little feedback on.
I'm building a scale model M1117 Guardian military vehicle. Although if I
build it properly it won't fly, I'm planning on using some composite
techniques that you guys are familiar with.

I have built a steel frame that will act as a role cage. My intentions were
to glue foam to the frame, then glass over the outside and inside. I haven't
actually worked with fiberglass before, so I could use some pointers. My
first question is weather there is a better core material than foam for my
application. I understand that foam has some heat issues that require white
paint. Obviously I would rather a nice pretty camo pattern. I'm not as
concerned with weight as I am strength, but I do need to keep it lighter
than 1/2 plywood. The body panels need to withstand multiple paintball hits,
and an occasional tree branch. My next concern is the possibility of my
steel cage causing the fiberglass to delaminate since it would be on the
inside of my composite.

Any suggestions from the experts?


--
"Don't be misled, bad company corrupts good character."
www.LCTPaintball.com
www.LCTProducts.com

[Morgans]

"Richard Riley" > wrote

> The steel cage, on the inside, won't get any hotter than the ambient
> temp of the inside. It's not sitting in the sun, it's in the shade.
> Desert cammo will be MUCH cooler than OD Green. But if you can
> survive in the temperature on the inside, the resin will be happy.
>
> If there is any softening of the resin (there won't be, but if there
> were) it wont cause any delaminations, just softening, so you might
> end up with a dent from a tree branch, etc. It would just add to the
> realism.

You would not need the steel cage, unless you need it for rollover
protection, and if that is the case, just do the roll bar and support.
--
Jim in NC

[LCT Paintball]

> If it were me, I'd use 1/8" plywood or corrugated cardboard as a core.
> A few plies of heavy (non aviation, ie, boat type) cloth on the
> outside, maybe one on the inside. Polyester boat resin (cheap, and
> not as suseptable to heat softening). Check out the heavier cloths
> here http://www.discountcomposite.com/glass.html and remember that
> we're paying about $6 per yard for 9 oz glass for homebuilt airplanes.

I like the cardboard idea. Do you think it would hold up to the moisture of
the resin? Would I be able to use Bondo to smooth sharp corners?

[LCT Paintball]

> here http://www.discountcomposite.com/glass.html and remember that

I checked out your link. Did you know there are LOTS of different types of
fiberglass cloth? OK, I guess you did, but I was amazed. Obviously I need to
learn some more about different types of weaves and fibers. Is there a good
tutorial online?

[LCT Paintball]

> the resin? Would I be able to use Bondo to smooth sharp corners?

Even better, how about paper mache?

[Dave S]

LCT Paintball wrote:
I understand that foam has some heat issues that require white
> paint.

My understanding is that in non-structural applications, this isn't such
a big deal. The high heat from dark painted surfaces in direct sunlight
can cause shrinkage of the foam core. In a wing or canard, this can be a
"VERY BAD THING" (TM).. but in a non-structural mockup, where the only
thing it has to resist is raindrops and paintballs, I wouldnt get too
excited over "core" shrinkage.

You could even do it over a light plywood or fiberboard core. Again,
this is for non-structural applications.

Dave