Fibre content GRP

[Dutch Peter]

Hi guys,

I need some experience from the field!

Is a glass content of 40% possible with the hand lay-up application method?

What I found on the net was 15% to 35% with spray-up at the lower end of that range and hand lay-up at the higher end and for vacuum about 50%.

So, for an experienced builder it looks to me the 40% could be done.
What you all think?

Regards,

Dutch Peter

[mmd]

Yes, with a few caveats, it is possible. The laminator need to be experienced and concientious. Small and complex shaped objects tend to accumulate higher resin content, big flattish laminates such as hulls are much easier to control. Pre-pregging the cloth aids quality control, but can be tricky to do.

[Dutch Peter]

[quote=mmd]Small and complex shaped objects tend to accumulate higher resin content.[quote]

But this would mean a greater thickness e.g. greater section modulus. Thus the loss in strenght, due to higher resin content, is compensated by lower stresses!? Correct?

Hi there,

Vacumn bagging is well worth the effort to set up for.
It makes it a lot easier to optimise your resin/fibre ratio's.
It also goes a long way towards avoiding the de-laminating problems that are associated with unconsolidated high fibre/resin ratio laminates.
I'd Vac bag my sandwiches if it didn't make them all sticky

Resin rich small parts tend to be understandably brittle.

Rob

[mmd]

Dutch Peter - the higher I/y is made moot by the mechanical properties of the extra resin; as Rob points out, it becomes brittle.

[Dutch Peter]

mmd, Rob,

Thanks for the info!