I am looking to make some carbon fiber parts for the car over winter however, as I don't have a bottomless pit of money, I am looking to use one layer of carbon matting and for subsequent layers use CSM or woven glass matting.

Firstly, can I use epoxy resin for the carbon and then poyester for the CSM or should I stick to epoxy for all layers and use woven glass ??

Secondly, watching the carbonmods video, they show the first layer into the mould being the epoxy resin, is the correct or should I use a Gel coat ?? I though there were UV issues with epoxy ??

Any help appreciated.

Thanks,

John

Epoxy and polyester don’t react. The epoxy is also clear where as most polyester resins are tinted so like you say best to use that for only the inner mat. If you buy decent epoxy it should be fine in UV, I use it as a sealant on my rc planes and boats (instead of varnish) and have never noticed any ill effects from sunlight, some have sat next to the window for over 15 years.

You can layup epoxy onto a polyester laminate, but not the other way around. Polyester does not like bonding to other materials... As such, you would either need to do the whole lot in one or the other resin, or lay your outer skin as the final layer (not a good idea for surface finish).

You can apply reson (either polyester or epoxy) into a mould prior to laying up - this is how you get a very high gloss finish without the need for lacquer. either wit for it to go off (epoxy), or tack (polyester) before continuing your layup. This should ensure a void free surface.

To avoid discolouration, go for a UV stable resin (polyester surfboard resin is good for this).

Yup. Epoxy onto cured polyester is fine but t'other way round doesn't work..... I epoxy laminated my scuttle reinforcements onto the GRP scuttle (including CF tows) and it's strong as a strong thing....

also the CSM is usually held together with a binding agent that is disolved by polyester resin, so check with your supplier if your planning to use CSM with epoxy

aitch