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As title says. Whats the weight difference between GRP and carbon?

Cheers
 

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FRP ?

depends on the amount of layers and the thickness of each.... a lot of variables.

in all equal circumstances, not a lot i think.
 

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For example:
Top Secret FRP Bonnet: 9kg
Top Secret Carbon Bonnet: 6kg
Not a fair example, as FRP/GRP bonnets are usually chopped strand, or chopped strand mat, whereas CF is always weave. (Although perhaps what the OP wanted to know)

If you used glass weave, weights would be similar, actually almost exactly the same per layer if the same weight cloth was used.

However, you might require another layer with glass to get the same stiffness as CF. So a little, but not much more in weight.

I doubt you can buy a weave FRP/GRP bonnet (for example) as the final cost will be too close to CF. It's a labour thing, not so much a material cost thing.
 

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cost of carbon weave is way above glass weave.

dry carbon is lighter than wet lay carbon due to the processes used (less resin)
 

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Proper dry carbon like the bonnets from Electra are much lighter -

carbon that is pre- impregnated with resin (pre-preg) is stored in freezers and has a finite shelf life before the resin starts to go off. Layed up in a mould layer by layer and then vacuum bagged and baked in a pressurised nitrogen oven (autoclave). Bleeder cloth and soak plies are used to remove excess resin. The pressure and vaccuum compresses the layers together for maximum strength.

Foam or honeycomb cores can be added for maximising panel stiffness whilst minimising weight.
 

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cost of carbon weave is way above glass weave.

dry carbon is lighter than wet lay carbon due to the processes used (less resin)
True but the cloth is still only a small percentage of the RRP of a Carbon Bonnet for example. Probably £50 worth of CF used in a £600 bonnet. Even if GF cloth was free, you wouldn't be able to sell GRP bonnets for £550, when you can get a carbon one for £50 more.

The bulk of the cost is labour, and scrap.

FWIW, Most CF body parts available only have a single skin of carbon over a GPR skeleton.
 
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