Fiberglass: How it Works

[bleedredandblue]

Okay, all, just getting into the boating world and trying to learn as much as I can. Here's the question.

Would anyone like to briefly explain - in basic terms - how exactly fiberglass works? Let's take the example of replacing decks. Guy gets his choice of wood, lays fiberglass mat, epoxy resin over the top and off he goes with a new deck, yes? So how exactly is the fiberglass adding strength? Is the process of it being "wetted" by the resin, then drying hard? I mean, to the lay observer, they'd pick up a package of mat, think, "Geez, this stuff weighs nothing. How on earth does it provide any strength?!" Likewise with hull repair - how exactly is the glass adding strength back to the hull on a repair? I know this is about as basic a question as you can get, but I always found it helps to know how something works, rather than just knowing that it does work, you know?

 

[Cadwelder]

Re: Fiberglass: How it Works

Okay, all, just getting into the boating world and trying to learn as much as I can. Here's the question.

Would anyone like to briefly explain - in basic terms - how exactly fiberglass works? Let's take the example of replacing decks. Guy gets his choice of wood, lays fiberglass mat, epoxy resin over the top and off he goes with a new deck, yes? So how exactly is the fiberglass adding strength? Is the process of it being "wetted" by the resin, then drying hard? I mean, to the lay observer, they'd pick up a package of mat, think, "Geez, this stuff weighs nothing. How on earth does it provide any strength?!" Likewise with hull repair - how exactly is the glass adding strength back to the hull on a repair? I know this is about as basic a question as you can get, but I always found it helps to know how something works, rather than just knowing that it does work, you know?

Well you've asked a very techical question....read this and it'll give you a brief overview of it. http://en.wikipedia.org/wiki/Glass-reinforced_plastic

 

[Luhrs28]

Re: Fiberglass: How it Works

It works on basically the same principle as steel reinforcing bars in concrete. Concrete (and resin/epoxy) have good strength in compression but poor tensile strength. So when you add strong steel bars (or fibers in the case of fiberglass) you're making a composite material with excellent strength in both tension and compression.

 

[bleedredandblue]

Re: Fiberglass: How it Works

Thanks, guys. Yeah, I kind of wondered if it was the same principle as rebar in concrete. The Wiki description of CSM was helpful too -

"Chopped strand mat or CSM is a form of reinforcement used in glass-reinforced plastic. It consists of glass-fibers laid randomly across each other and held together by a binder.

It is typically processed using the hand lay-up technique, where sheets of material are placed in a mold and brushed with resin. Because the binder dissolves in resin, the material easily conforms to different shapes when wetted out. After the resin cures, the hardened product can be taken from the mold and finished."

Resin dissolves binder, mixture hardens, glass fibers become equivalent of rebar (or so I understand it), and off we go.