Ducati Monster Forum

Moto Board => Tech => Topic started by: angler on April 16, 2009, 02:57:04 PM

Title: Milky carbon
Post by: angler on April 16, 2009, 02:57:04 PM
I have a carbon fiber cowl that came with the bike.  I haven't really had it on the bike that much, but I put it on the bike last week.  I store the bike outside under a cover.  The next day, I pulled the cover and the top of the cowl had gone all milky white.  What happened?  How can I fix it? It has gotten a little better since it quit raining and warmed up.

Its a bummer, too, because all I really wanted to trade it to someone for a stock one! Not a big fan of the CF.
Title: Re: Milky carbon
Post by: ducpainter on April 16, 2009, 03:02:26 PM
Moisture in the resin.

What year bike and what color you looking for?
Title: Re: Milky carbon
Post by: erkishhorde on April 16, 2009, 03:07:10 PM
When CF ages the clear coat or the resin can get sun damaged and will turn white or yellowish. If it's really bad the only solution I've heard of is to wet sand it to get rid o the damaged part and then re-clear it. I've been meaning to do this to my damaged rear hugger but never got around to it. Takes time.
Title: Re: Milky carbon
Post by: angler on April 16, 2009, 03:40:59 PM
Quote from: ducpainter on April 16, 2009, 03:02:26 PM
Moisture in the resin.

What year bike and what color you looking for?

2005 S2R - Dark.
Title: Re: Milky carbon
Post by: BastrdHK on April 16, 2009, 10:30:03 PM
I'll buy the cowl if you find a dark one you like.  PM me and let me know if your interested.
Title: Carbon Fiber Care
Post by: Shazaam! on April 16, 2009, 11:01:19 PM
Carbon fiber composites get brittle and faded from oxidation caused by the sun's UV rays. The UV discoloration is a combination of both the carbon and the resin color changes, so in order for carbon fiber to retain its appearance, it has to be clear-coated by either the manufacturer, or you, prior to installation. If it's shiny direct from the manufacturer, it's probably been clear coated. But check first before buying.

Since exhaust cans operate at elevated temperatures, this will accelerate this oxidation and also quickly drive off any wax, oil or silicone coatings you apply to try to keep them shiny. Automotive paint clear coats are very resistant to UV discoloration and oxidation, so the best solution, even for carbon exhaust cans, is to spray them before installation.

To restore carbon fiber that has started to fade, wash it with soap and water, rinse it with paint thinner, and let dry. Apply three or four coats of clear acrylic enamel or lacquer, the first coat just misted on. Lightly sand with 600 wet between coats. The black won't be as deep in any faded areas, but pretty-close.

Clear-coating carbon fiber can be time consuming because of the pinholes in the material. To keep it lightweight, it shouldn't contain any more resin than necessary. Nevertheless, some manufacturers focus more on the cosmetic aspect, so their products are dense with resin and very shiny.

Unless your carbon fiber has been clear-coated, keep Windex or harsh oxygenated cleaners like 409 or S-100 or Oxyclean away from it. They turn raw carbon fiber mottled white and milky-looking. In some instances this milky stain can be removed with denatured alcohol before clear-coating.
Title: Re: Milky carbon
Post by: angler on April 17, 2009, 08:17:32 AM
Excellent stuff.  Ducpainter has offered to trade me a stock one.  Be gone evil CF.......