ribs?
02GF74 - 7/8/07 at 08:04 AM
I want to strengthen my scuttle by putting some reinforcing ribs. (the scuttle is cruved) Looking for something cheap and light.
So what is a good way of doing this?
A couple of ideas;
a) use 20 mm pvc tubing glued in place
b) strips of corrugated cardboard
c) paper tube filled with the expanded foam stuff
and then layer fibre glass over it.
All ideas welcome, especially the good ones.
stuart_g - 7/8/07 at 08:17 AM
Balsa wood covered in fiberglass?
Richard Quinn - 7/8/07 at 08:29 AM
Anything that is normally used as a core in composites. Coremat or similar is pretty good for this type of thing
twybrow - 7/8/07 at 08:36 AM
balsa, pvc foam. Cardboard is a big no no - it can react with the catalyst in the resin and cause fires!
donut - 7/8/07 at 08:37 AM
Fiber glass in some ally strips.
stuart_g - 7/8/07 at 09:40 AM
quote:
Originally posted by twybrow
balsa, pvc foam. Cardboard is a big no no - it can react with the catalyst in the resin and cause fires!
not if you use polyeaster resin, which is more likely to be what the original panels are made with. Epoxy resin will probably not be compatible and
won't stick to polyester resin.
I and many other people in the model making industry have used fiberglass on top of balsa wood and it does not catch fire.
twybrow - 7/8/07 at 09:52 AM
Stuart - read the post. I said dont use cardboard, not balsa. I have made 140' long boats and they didn't catch fire either. I gatherered
from his post that he was using polyester and not epoxy. Epoxies dont have catalyst, they use hardener. Polyesters use catalyst and it is that
catalyst (MEKP) that can cause problems with cardboard.
[Edited on 7/8/07 by twybrow]
stuart_g - 7/8/07 at 10:03 AM
quote:
Originally posted by twybrow
Stuart - read the post. I said dont use cardboard, not balsa. I have made 140' long boats and they didn't catch fire either. I gatherered
from his post that he was using polyester and not epoxy. Epoxies dont have catalyst, they use hardener. Polyesters use catalyst and it is that
catalyst (MEKP) that can cause problems with cardboard.
[Edited on 7/8/07 by twybrow]
Sorry, mis read the reply.
A lot of people mistake the resins used in the manufacture of fiberglass, I have and you end up with a sticky mess everywhere
twybrow - 7/8/07 at 10:13 AM
No worries Stu. I think i have the best sticky mess story - I know of a guy who was infusing a 90' boat. Someone forgot to ensure the reisn
mixing machine was working. The team were left scratching their heads 4 hours later, wondering why the resin hadn't gone off. Now that is a very
big, very expensive mess!
02GF74 - 7/8/07 at 12:43 PM
intersting ..... so how do I tell if I have polyester resin in the oringianl scuttle?
the stuff I intend to use is from CFS - which if memory serve well, uses the MEKP(?) catalyst.
BenB - 7/8/07 at 02:11 PM
I'm sure it'll be polyester... To make a scuttle out of epoxied GRP would cost serious amounts of money.....
Also, epoxied GRP is very stiff compared to polyester. If you're needing to re-inforce it, its likely to be polyester!! Apparantly you can tell
the difference between polyester and epoxy by the colour and shape of spiral fragments when you drill it. But'll itl be polyester 
Trying to stick polyester onto cured epoxied GRP is damn difficult. Using epoxy on cured polyester is okay. Strange eh!
Personally I'd buy some carbon toes (cheap as chips) and lay them in a grid pattern under the scuttle and epoxy them in place with West System.
Epoxy impregnated carbon toes go bloody hard!!! They're lightweight but stiff. I used them for re-inforcing my scuttle.. Well rigid now.