Plastic & resin · 1 min read
Sanding carbon fibre (CFRP): refreshing the clear coat without hitting the fibres
You only sand the resin or clear coat layer above the weave: wet from P320 to P600 before new clear coat, P1500 to P2000 before polishing – and wear a mask.
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Only the top layer, never the weave
Visible carbon has a layer of resin or clear coat over the weave. Only this layer gets sanded. As soon as the fibres are sanded, the weave turns matt and frayed at that spot – that can only be filled with new resin or clear coat, not sanded away.
The top layer is thinnest on edges and curves. Work there by hand with light pressure, and only use the sander on flat areas.
Renewing yellowed clear coat
If the clear coat is yellowed, cracked or scratched: wet-sand with P400 to P600 until the surface is evenly matt everywhere, without going through on the edges. Then new clear coat – UV-resistant, or it will yellow again. Before the first coat on bare CFRP, clean off release agent thoroughly first, then sand matt with P320 to P400.
Individual fine scratches in intact clear coat: P1500, then P2000 wet, only as far as necessary, then polish.
Dust and mask
CFRP dust is very fine, itches on the skin and must not get into your lungs. Sand wet or with dust extraction, wear at least an FFP2 mask, gloves and long sleeves. Don’t let the sanding slurry dry – wipe it up while it’s wet.
FAQ
Can I sand carbon-look wrap?
No. Carbon-look wrap is only printed – even P2000 sands the pattern away. At most, treat wrap with a very fine polish made for films.
How do I know I’m reaching the fibres?
The sanding slurry gets darker and the weave pattern stands out matt and rough instead of shining under the clear coat. Stop immediately.
Terms in this article
All terms in the sanding glossary →The whole sequence at once
5 grits, 1 × smallest pack each: PRO FILM 150 (10 pcs) P320 · P400 · P600 · P1500, SOFT FINISH (10 pcs) P2000.
Or as a set: Finish set for high gloss (P1000–P2000) for €59.90 →
incl. VAT, plus shipping
