Can you wet lay carbon fiber over GRP.
Discussion
was wondering if you cold wet lay CF cloth onto GRP. It's not for strength, but would help if it could improve this a bit.
the idea is the car will need a re-spray, but the idea is to take the gelcoat off the GRP and wet lay CF onto the GRP. and leave the car with the CF finish. and either re-Gelcoat or get the car lacquered. it will be on a track car, so the finish would not have to be perfect. also I think the body would be too big to vacuum.
I want to know if this would work and if the CF would bond ok to the GRP, if it would what would the best resin be.
the idea is the car will need a re-spray, but the idea is to take the gelcoat off the GRP and wet lay CF onto the GRP. and leave the car with the CF finish. and either re-Gelcoat or get the car lacquered. it will be on a track car, so the finish would not have to be perfect. also I think the body would be too big to vacuum.
I want to know if this would work and if the CF would bond ok to the GRP, if it would what would the best resin be.
TVRleigh said:
was wondering if you cold wet lay CF cloth onto GRP. It's not for strength, but would help if it could improve this a bit.
the idea is the car will need a re-spray, but the idea is to take the gelcoat off the GRP and wet lay CF onto the GRP. and leave the car with the CF finish. and either re-Gelcoat or get the car lacquered. it will be on a track car, so the finish would not have to be perfect. also I think the body would be too big to vacuum.
I want to know if this would work and if the CF would bond ok to the GRP, if it would what would the best resin be.
this is very much an "IMO".. erm... opinion, but I'd say it would be fairly pointless, expensive, not very successful and likely to look a bit like a train crash.the idea is the car will need a re-spray, but the idea is to take the gelcoat off the GRP and wet lay CF onto the GRP. and leave the car with the CF finish. and either re-Gelcoat or get the car lacquered. it will be on a track car, so the finish would not have to be perfect. also I think the body would be too big to vacuum.
I want to know if this would work and if the CF would bond ok to the GRP, if it would what would the best resin be.
Wet layup really needs a mould to be pushed into to get any sort of decent result. Gel coat goes in first, not last, and is a thick gooey version of the resin used. I think you'd be very, very unlikely to get a satisfactory result. A large mess, very likely.
ETA: but back a bit to the original question, yes you can effectively glue carbon cloth to GRP with a bit or resin!
Edited by Davi on Tuesday 21st August 16:42
Thank you for your advice.
May be better to go with the cheeper option of carbon look stick on vinal.
but was thinking may be better to stick CF cloth to the GRP, and maybe add some strengh, if so I could remove more GRP. and save a little bit of weight.
I know it would be espensive ish, about £500 but that's still cheeper than a re-spray. the vinal would only be 100 ish though, and a lot quicker.
The plain would be to re-make pannels when I have time CF, this why it would not look too out of place.
Also would look better than the green of the car currently.
I will get CF kit and do some experiments.
May be better to go with the cheeper option of carbon look stick on vinal.
but was thinking may be better to stick CF cloth to the GRP, and maybe add some strengh, if so I could remove more GRP. and save a little bit of weight.
I know it would be espensive ish, about £500 but that's still cheeper than a re-spray. the vinal would only be 100 ish though, and a lot quicker.
The plain would be to re-make pannels when I have time CF, this why it would not look too out of place.
Also would look better than the green of the car currently.
I will get CF kit and do some experiments.
Davi said:
TVRleigh said:
was wondering if you cold wet lay CF cloth onto GRP. It's not for strength, but would help if it could improve this a bit.
the idea is the car will need a re-spray, but the idea is to take the gelcoat off the GRP and wet lay CF onto the GRP. and leave the car with the CF finish. and either re-Gelcoat or get the car lacquered. it will be on a track car, so the finish would not have to be perfect. also I think the body would be too big to vacuum.
I want to know if this would work and if the CF would bond ok to the GRP, if it would what would the best resin be.
this is very much an "IMO".. erm... opinion, but I'd say it would be fairly pointless, expensive, not very successful and likely to look a bit like a train crash.the idea is the car will need a re-spray, but the idea is to take the gelcoat off the GRP and wet lay CF onto the GRP. and leave the car with the CF finish. and either re-Gelcoat or get the car lacquered. it will be on a track car, so the finish would not have to be perfect. also I think the body would be too big to vacuum.
I want to know if this would work and if the CF would bond ok to the GRP, if it would what would the best resin be.
Wet layup really needs a mould to be pushed into to get any sort of decent result. Gel coat goes in first, not last, and is a thick gooey version of the resin used. I think you'd be very, very unlikely to get a satisfactory result. A large mess, very likely.
ETA: but back a bit to the original question, yes you can effectively glue carbon cloth to GRP with a bit or resin!
Edited by Davi on Tuesday 21st August 16:42
A respray would look miles better than anything you are likely to achieve laying up on the outside of an existing panel.
I can't see adhesive vinyl working much better either to be honest (might struggle with the compound curvature of most panels)
it will look s**t mate trust me im a composite worker for roll royce so i know my stuff.it will have a bad finish cus your laying it on top of something and putting resin on the cloth you wont get the resin to look even all over even with vacuum bagging youll get marks all over it because of the realease film.you better of taking a flash of the panel you want carbon then laying carbon inside that and use the vacuum method then youll get the nice finish.hope that helps cheers daz.
TVRleigh said:
I want to have a real CF hood / bonnet ... would be a waste to have the car sprayed.
These two seem rather at odds. Carbon fibre outside an existing panel is a pointless fashion gimic that will take a lot of time and money and still look naff, and probably start falling off the moment you have a slightest scrape. Painting will be a heck of a lot easier and cheaper, look better, be more practical etc. For a track car I can't think of any possible reason to justify throwing money at CF. If it's a show car with money no object and a particular look you want that's a different matter.Just my £0.02.
Was just an idea, instead of getting it sprayed. hence posting on here before wasting money.
I just thought just skining the car would be easier and cheeper then re-making the whole car in CF. and as GRP and CF are both resin bonded then they should bond together.
whats the best way to make flash molds.
Thanks for all your advice.
I just thought just skining the car would be easier and cheeper then re-making the whole car in CF. and as GRP and CF are both resin bonded then they should bond together.
whats the best way to make flash molds.
Thanks for all your advice.
TVRleigh said:
Well I want to have a real CF hood / bonnet., and the rest to match, also it will not have to look good close up. as will be on a track car, just wanted somthing a bit different, and would be a waste to have the car sprayed.
If it's only for a track car and you aren't worried about looks, then spend the cash on something that will help you go faster!If it's intended for cosmetic reasons, the big problem is that you'd never get a smooth surface finish and still be able to see the carbon fibre.
If you just 'painted' over the carbon cloth with clear resin/gelcoat, the weave would show through and you'd end up with a 'textured' surface.
If you tried to rub the surface smooth, you'd never get a consistent finish.
I've used carbon fibre for mouldless construction by laying-p over a shaped foam core (this technique was pioneered by Burt Rutan for his VariEze homebuilt aricraft), but to get a decent surface you pour a 'slurry' of resin mixed with 'microballoons' (a lightweight powder of tiny glass bubbles) over the carbon fibre, which - with enough effort - can be sanded smooth give a very high quality finish and a strong, lightweight structure ...but you cant tell it's carbon fibre as the microballoon slurry is opaque & has to be painted to achieve a consistent colour when you've finished. This technique could, conceivably, be used to laminate over a GRP moulding with carbon fibre for extra strength/stiffness, but it would be incredibly time consuming to get a decent finish so realistically it would be far more sensible simply to have a whole new bodyshell laminated in carbon fibre using conventional wet lay-up techniques into a female mould.
If you just 'painted' over the carbon cloth with clear resin/gelcoat, the weave would show through and you'd end up with a 'textured' surface.
If you tried to rub the surface smooth, you'd never get a consistent finish.
I've used carbon fibre for mouldless construction by laying-p over a shaped foam core (this technique was pioneered by Burt Rutan for his VariEze homebuilt aricraft), but to get a decent surface you pour a 'slurry' of resin mixed with 'microballoons' (a lightweight powder of tiny glass bubbles) over the carbon fibre, which - with enough effort - can be sanded smooth give a very high quality finish and a strong, lightweight structure ...but you cant tell it's carbon fibre as the microballoon slurry is opaque & has to be painted to achieve a consistent colour when you've finished. This technique could, conceivably, be used to laminate over a GRP moulding with carbon fibre for extra strength/stiffness, but it would be incredibly time consuming to get a decent finish so realistically it would be far more sensible simply to have a whole new bodyshell laminated in carbon fibre using conventional wet lay-up techniques into a female mould.
Sam_68 said:
I've used carbon fibre for mouldless construction by laying-p over a shaped foam core (this technique was pioneered by Burt Rutan for his VariEze homebuilt aricraft), but to get a decent surface you pour a 'slurry' of resin mixed with 'microballoons' (a lightweight powder of tiny glass bubbles) over the carbon fibre, which - with enough effort - can be sanded smooth give a very high quality finish and a strong, lightweight structure ...but you cant tell it's carbon fibre as the microballoon slurry is opaque & has to be painted to achieve a consistent colour when you've finished. This technique could, conceivably, be used to laminate over a GRP moulding with carbon fibre for extra strength/stiffness, but it would be incredibly time consuming to get a decent finish so realistically it would be far more sensible simply to have a whole new bodyshell laminated in carbon fibre using conventional wet lay-up techniques into a female mould.
Indeed - I've used this method on a few things, from a large scale model boat hull to repairs on existing GRP.Even something as simple (in terms of compound curves) as a boat hull cause no end of problems, and took literally weeks. Doing a whole car... no ta.
If you are after the CF look for looks sake alone, definitely forget it unless you plan to invest time and money on having the whole car cast, or just have the panels you intend to have remade done, then spray them with the car. If you are doing it because you want to reduce weight and increase strength - invest time and money and have the whole car done.
If you want the whole car done, and have never done anything like this before... good luck.
Alternatively, get it sprayed

Just picked up on this thread, What did you decide. I think the consensus was don't bother. I have to say the thought of wet layCF over GRP would be nigh on impossible to do with the weave of CF, it would look very very bad unpainted.
If you do use the sanding technique you have to be so carefull not to pick up any fibers. wait till you get racing and someone else will have moulds they might lend/hire.
Best of luck.
If you do use the sanding technique you have to be so carefull not to pick up any fibers. wait till you get racing and someone else will have moulds they might lend/hire.
Best of luck.
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