Carbon fibre is prized for its lightness, stiffness and distinctive look. It is used for bicycle frames, motorcycle parts, car body trim, sports equipment and professional tools. But it is a technical material and needs careful handling.
The carbon weave is always sealed under a resin, usually epoxy, which shields it from moisture, UV light and scratches. That glossy or matt top layer is what harsh chemicals, abrasive sponges or high-pressure jets damage most easily.
What you will need
Important: Never apply any product to the braking surfaces of carbon rims, brake discs or pads. Avoid acidic cleaners, solvents, abrasive compounds and pressure washers, as they can permanently damage the protective resin.
Step 1
Know what you are working with
Check the finish: gloss lacquer, satin or bare matt resin. This decides the final treatment. Also check the condition of the surface: cracks, bubbles or lifting lacquer mean the part should be seen by a specialist, not just washed.
Step 2
Rinse off dust and grit
Start with clean warm water from a spray bottle or watering can, with no pressure. The aim is to remove sand and road salt, which act like sandpaper under a sponge. Never skip this step in winter or after wet rides on dirt roads.
Step 3
Wash with a gentle cleaner
Apply a mild shampoo solution with a sponge and go over the part without pressing. Do not scrub dried mud; let it soak for 2-3 minutes instead. Then rinse with warm water.
Metal fittings, bolts and joints next to the carbon can be treated with WD-40 Smart Straw to drive moisture out of the threads, but keep the spray well away from the brakes.
Step 4
Dry thoroughly
Pat the surface dry with clean microfibre so no droplets remain. Dried hard-water marks are very visible on dark carbon, especially on gloss.
Step 5
Protect matt surfaces
On a dry matt or unlacquered part, apply a thin coat of WD-40 Multi-Use: spray it onto a cloth and spread it evenly with no excess. The film repels moisture, reduces water spotting and refreshes the look without leaving the surface greasy.
Step 6
Bring up the shine on lacquered carbon
For gloss finishes use WD-40 Specialist Silicone. Shake the can, spray from 10-20 cm onto a cloth or the part, spread it out and after a few seconds buff with a clean microfibre cloth in circular motions. The finish shines, repels moisture and attracts less dust.
Tip: Test any product on a hidden area before first use. Some matt finishes darken slightly after treatment, and it is better to know in advance.
What next
Wash carbon parts after every muddy or rainy outing and never leave dried road salt on them until spring. Never scrape off dried marks with metal tools or abrasives; soak them with water again instead.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».