Difference between woven roving and fiberglass cloth?

General Composites Discussions Composites Talk
#1

I need to choose a fabric for my race bike project. Weight is not a big issue, I was thinking of using 1 layer 6oz. S-Glass (just because its what I have)and either 2 layers of 9oz fiberglass or 18oz woven roving.

I was wondering what the difference between 2 layers of 9oz glass vs. 1 layer of 18 oz. woven roving?
or
would I be better off just doing 5 or so layers of s-glass or e-glass. Im trying to keep this project cheep :slight_smile:

I would be laying strips of the heavy fabrics so it will form to the molds. Also it would be infused.

#2

To keep things cheap use one layer of 300gm glass, followed by a light cloth. Laminate using poly resin with flex additive. If its for a race bike, then you must keep it as light and flexible as possible.

#3

I was under the impression that woven roving could not be used since they are not epoxy compatible??!! or am I mistaken?

Could you please elaborate about the flex additive? I would assume that this is necessary since the poly is more rigid?

#4

Unless you want to waste money there is no reason to use epoxy resin systems for race fairings. The whole point of race bodywork is to make it as inexpensive and flexible as possible, as it takes very little to damage it irreparably.

#5

LOL, I need to shave some weight off my belly before I shave it off the bike :smiley:

Thanks, I will be ordering some glass this week.

#6

You are always better off with many layers of lighter weight FG cloth cut in the different directions (0, -45, +45 and 90 degrees) than 1 layer of heavy weight material.

#7

You’re thinking Chopped Strand Mat.

#8

Flex additive is something I have not used, I did a search and found the Revchem resin posts(mix 10% ect…),I will contact them and see if I can get some, unless there is something better someone knows about.

also can the Revchem resin or something else be used with vinyl ester? for future ref.

#9

Any supplier of poly resin systems for industrial applications, will probably be able to help with flex additive. When making race plastics using this additive, you need to apply a single thin gel-coat, otherwise you may have problems with the gel cracking/crazing.

This is the way to make plastics intended for proper race applications, but if you are primarily intending to use the bike on the road, then make lay up thicker, and forget the flex additive and thin gel-coat.