I'm curious if I should be using anything on my prepreg parts after they come out of the mold. Still waiting on my prepreg but did a wet lay test in my mold and the finish is excellent but I'm curious about polishing and uv protection. My parts will be exposed to sunlight and I would very much prefer to not clear coat. I noticed a couple products, one of them being easygloss polish and protect. Does this stuff work? Will it give a nice shine and actually protect from uv? Other thing is, the parting line on my mold is excellent, almost invisible on the part, but you can feel it. Not sure if I should maybe try a very fine grit on a block, like 2000 or so, but then would need to polish any marks out. The line is on a convex surface so should be able to hit it with a flat block and barely touch any of the part surface, but I'm sure there would be at least a 1mm or so wide line of sanded surface that would need to be polished back down. If I go that route, might be better to use a strip of epoxy sheet right on the seem in my mold to give something to sand and polish. Maybe better to not touch it and just live with feeling a line when you run your hand across it. 
Anyway, mostly just curious about treating the part after coming out of mold if there's no clear coat going on. 

As said you have to be very careful as you can sand/polish into the carbon.  Generally you can use the high wax content "finishing" polishes as usually they have zero or very little abrasive content and mostly work by applying the wax to the surface.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Ok, I'll leave the line alone. As I said, the parting line is almost non existent so trying to get rid of it is gonna be a lot of work for not much pay off. My aluminum molds are referenced together with steel dowel pins and I sanded/polished along the joint while the mold was closed so it's a really tight joint. 

The EasyGloss is a brilliant product, it really is. Applied properly (with a good machine polisher and a soft black pad), it will add an extra gloss and depth to finished parts. 

As for the UV protection,  that's really anyone's guess - it's too new a product for anyone to have any actual data on that. Realistically, it is a wax and will work the same as automotive protective waxes. It will add a little bit of protection, and will need fairly regular treatment to last as long as possible, it's not a case of apply it once and have a UV resistant part for 20 years. It's also going to depend a lot on the specific resin that your pre-preg is using, some are much more sensitive than others. The X-Preg is very good for an epoxy, all the parts I have made with it are still as good as the day I pulled them out of the mould. The old EasyPreg wasnt quite as good, a lot of those parts I made have lost their gloss a bit and require more regular treatment with the EasyGloss. 

Personally, I like the EasyGloss and it's a bit of added protection. There is no real guarantee that clear coats provide any more protection than that either, it is very subjective. It's best to be realistic and accept that all resins are UV sensitive plastics, and will not last forever.