Ski Builders Forum

Hi all,

Some one known what kind of coating it is on fiberglass?
Looks that it is spread from one side, fiberglass feels more stiffer..
I found that coated fiberglass much better squeeze out bubbles from resin during press.
Pictures of coated fiberglass attached

A quick google search only showed fiberglass with either silicone or teflon coating. If that is what you have I wouldn't try to build skis with it as both materials prohibit bonding.

Where did you get that coated glass?

I bought this glass few years ago from local shop, but they don't know what kind of coating is...
Spray on fiberglass looks transparent, fiberglass soak with resin very well, no any delamination issue..

But definitely this coat is not silicone or teflon..

Could it be pre-cured with a small amount of epoxy?

Ok will try tomorrow

No, what I meant was maybe the coating is a pre-cure with epoxy resin...that would at least explain that it is stiffer.

yes seems like it is sprayed with epoxy or another epoxy friendly material..

It looks like a kind of pre-preg, the resin is applied to one side only to stabilise the weave, then when you heat and apply pressure from a press or autoclave, the resin reduces in viscosity and impregnates the fibres.

Either that or it's just a weave stabiliser, although as there are cross fibres in there it doesn't seem to me to be that

Interesting, how to spray epoxy?

I don't think that this is what you are asking but it is interesting that all glass fibre is coated in the manufacturing process to stop the fibres from abrading each other and for the resin to stick effectively to the fibres.
The process of coating is called sizing and often products called silanes are used. This allows the fibres to be formed into rovings (bundles of individual fibres) and then into cloth or unidirectional fabrics.
There are some newer methods of sizing called direct sizing that is often used on aramid and carbon clothes because conventional sizing required temperatures that aramid and carbon don't tolerate in manufacturing.
Anyway just thought I would add it in as all glass is coated in the beginning but yours sounds like it is the fabric that has been coated. Possibly a binder has been applied to stabilise the weave? Or as others have said it is a form of pre-preg, but pre-preg fabrics usualy need to be kept refrigerated to stop the resin kicking.
Here is an article about glass fibre sizing (which has nothing to do with the size of the fibres it is just a name for the coating process!)
http://www.compositesworld.com/articles ... er-sizings

Hey falls great link.
I have been doing allot of research in sizing for nylon textiles I didn't realize they sized composite fabrics. But it makes sense.

Thanks falls, information really helpful!

It's kinda hard to see but it might be a very thin PA mesh that is applied to stabilize the fabric. This helps a lot to maintain the fiber angle for a biax fabric during handling.

cheers, Reto