I have carbon fibre mountain bike frame that had a couple of scrapes. I used fine wet n dry followed by polishing compound to remove them.

Unfortunately the rest of the frame is a matt finish so the part I polished (top tube) does not match, hence the question of how to I make the surface matt?

Two options that spring to mind; one option is to use a matt clear lacquer and second is to blast it with very fine media such a bicarbonate of solder. The blasting appeals more as it obviously is quicker and means there will be no overspray but the frame has thin walls so I do not want to risk damaging it by the blasting. Also don't want the surface to end up porous so that it holds in dirt.

As usual, all ideas welcome.

Stop at the 1200 wet n dry? Don't do the polishing.

[Edited on 4-12-16 by loggyboy]