Hello, new here.

Been making some out of autoclave parts in prepreg, but I'm having problems with pinholes. They are very small. Lacquering and sanding time and time again doesn't seem to work. I believe they must be filled. Looking around the web, most products made specifically for the job seem to be American. Does anyone know how to do this efficiently? Needs to be cheap, quick and easy. It will need to be lacquered afterwards for UV protection.

Thanks

Turtlewax enriched polish and wax has a chip stick which you can use. Was recommended on a easy composites guide that came out a few weeks ago.

If you apply any wax based product then you won't be able to clearcoat on top of that. The only way I have been able to get rid of them completely is to keep applying clearcoat and sanding until they are filled level with the surrounding surface. I have also used black shoe polish to fill/conceal the pin holes after clearcoating, not really a fix more of a cheat. But it does tick the cheap and quick boxes.

you can use a black filler... either a black body filler or some epoxy filler.

Pin holes will drive you to drink. Scuff and respraying doesn't fill these holes. You have to abrade these holes or they will just repel your clear coat. I have tried a needle point dremel bit and just touch the holes and then mixing clear coat and waiting till it starts to kick and then filling the holes one at a time with a tooth pick. It's bush league but fills then like a filler. Once I have them all filled proud I wet block sand flat and then the clear will lay down nicely when sprayed. Here is what I think is going on in regard to the pinholes seeming to repel clear coat. When epoxy cures a film comes up to the surface. I think it is called alum blush. It is a waxey material that gets removed when we scuff and prime wash before spraying clear. But! you don't remove it from the pin holes by this action. Therefore the repelling is as if it has wax in the bottom of the pin hole. I just today ordered a thing called a sanding pen which auto refinishers use. I hope this will be fine enough to get into these pin holes.
Hope this helps.
Fred  

http://www.fibreglast.com/product/Glass_Microspheres_22/Fillers
they have a tutorial where they use this on a RC aircraft cowling. with such small
size of the filler it SHOULD spread easy and sand easy.
tips for filling "pinholes" as we call them in bondo -- is you can use a razor blade to wipe it in.then sand smooth
you can wipe it is with a stick or other instrument, and sand.
on bondo i have wiped it in the pinholes and then go back over with a cloth soaked in thinner, but not dripping wet,and wipe it
and it will smooth over the pinholes and no sanding . this technique SHOULD work on resins.

and yes OPEN the holes up with a tool of some sort. it makes filling them much easier

CarbonFiberCreations

Ok Brasco but if you still want to keep a transparant 'coat', to be able to see the carbon this is impossible...

ack!! i made a mistake --sorry. this is for the finished product then damn now i feel like a bonehead !!
i was thinking for the mold or the plug. sorry for the confusion guys --my mistake here.

CarbonFiberCreations

Thanks for your replies.

why not doing te same with epoxy and a sponge or something? have no idea what results it might give