ok...weird fiberglass question

[myx17]

As many of you know, I got a 1984 glastron conroy from my brother in law for free. It has been my project boat for a many weeks now. I have since ripped the entire interior out, replaced stringers and pretty much every piece of wood I could find. I am getting ready to glass the stringers and of course a new floor in, when a buddy of mine told me to use cotton type material instead of the fiberglass matt ? He said it would end up being stronger ? This of course made me curious so I figured I would jump on here and ask. Has anyone done this or attempted this ? Would this be true ? Thanks for the help once again.

 

[drewpster]

Re: ok...weird fiberglass question

Cant see how cotton can be stronger than woven glass fibers, but who am I to judge. Seems to me that cotton would wick water in to the layup more readily than glass as well. (but fiberglass does that too)

Polyester- use Chopped strand mat and woven roving or biaxial/ triaxial (a csm-cloth combo)

epoxy- woven fiberglass cloth

both are proven methods

 

[myx17]

Re: ok...weird fiberglass question

thank you brewpster. I was kinda thinking the same, but like I said, I wanted too jump on here and ask. You guys here have given me so much help already. Thanks again

 

[Mark42]

Re: ok...weird fiberglass question

Your buddy may have seen the custom auto speaker builders use cotton fabric then cover with resin. They do this all the time on the car programs. But believe me, it is far from strong. It soaks up too much resin, so the resin/material ratio is way wrong, and cotton is not strong at all.

Stick to fiberglass. Its what boats are made of.

 

[NSBCraig]

Re: ok...weird fiberglass question

Yeah - no!

 

[oops!]

Re: ok...weird fiberglass question

Your buddy may have seen the custom auto speaker builders use cotton fabric then cover with resin.

Stick to fiberglass. Its what boats are made of.

this is more than likely correct.

fiberglass is just that .....glass fibers.....when encased in resin....this product can be as strong as steel.

the car speaker box builders do not use the strength that true fiberglass provides .....as well they needed the curves that fiberglass will not do. so they use fleece....yep...just like you have in your sweat shirt. this is a cotton polyester blend material.
using this method....they can form a shape easilly with out going thru the mold making process and can make one-offs easily.

but bear in mind....they dont hang a 150 hp johnnyrude off the back end and blast down the lake at 60 mph.

 

[mogfisher]

Re: ok...weird fiberglass question

I'm one of those car audio guys and yes, we use fleece. When we did a system for a Patriots player we actually used patriots logo fleece. You don't see it once it's complete but it's funny that it's under there anyway. It works great as a "mold" of sorts. We staple it accross a rib structure of wood or what have you and add resin to make it hard. Once the resin cures though it is not very tough. If I wanted to i could probably punch through it with my hand. (1 layer). We use good ole csm and add a couple of layers to make it strong enough to handle even a subwoofer, nevermind an outboard. It's funny, though. For some reason one of the installers years ago bought TONS of 18 oz woven roving that we will never use so now I get to use it on my boat!