I've heard of restoring carbon fiber by wet sanding and clear coating but I never got around to it because it sounds like a lot of work. I was at a bike night a little while ago and was told of a way to restore white carbon fiber w/o sanding. He said something about rubbing alcohol or something to evaporate the water and then re-clear it. Ever heard of such a method? I'm sure it's been gone over but any suggestion on a rattle can clear?
Oh, found this on Speedzilla. Thoughts?
QuoteCarbon Fiber Care
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.
What is denatured alcohol? Where does one get such a product? I'm not sure I've ever seen it before.
You can't apply any coating wihout prepping the surface.
Clears require mechanical abrasion (sanding).
I'd agree with the Speedzilla article other than the part about applying clear over a non sanded surface.
I'm not sure exactly what de-natured alcohol is...
but you can buy it at a hardware store...
in the paint section.
So the sanding is more for the clear coat to adhere to rather than removing bad stuff?
Quote from: erkishhorde on May 16, 2009, 06:24:28 PM
So the sanding is more for the clear coat to adhere to rather than removing bad stuff?
Bingo
Is it better to clear coat paint or add more epoxy resin? Seems the resin would be thicker and more durable on the exhaust in particular. Surface prep would be the same though - sand, sand, sand to get the surface profile.
Quote from: Tigermeat on May 18, 2009, 12:03:14 AM
Is it better to clear coat paint or add more epoxy resin? Seems the resin would be thicker and more durable on the exhaust in particular. Surface prep would be the same though - sand, sand, sand to get the surface profile.
You do not want to sand through the old clear coat. If you sand into the weave you'll wind up with pin holes in the new clear, and you'll be veeery pissed off.
Quote from: Tigermeat on May 18, 2009, 12:03:14 AM
Is it better to clear coat paint or add more epoxy resin? Seems the resin would be thicker and more durable on the exhaust in particular. Surface prep would be the same though - sand, sand, sand to get the surface profile.
Most epoxies have no UV resistance so you'd be adding more material that will fail.
Use a urethane.
I'd like to do my exhaust cans too, but I thought the heat from the metal end caps would melt the clear coat.
Is it fine to just mask the end caps then spray onto the CF?
Quote from: Yellow Meanie on May 18, 2009, 08:33:43 PM
I'd like to do my exhaust cans too, but I thought the heat from the metal end caps would melt the clear coat.
Is it fine to just mask the end caps then spray onto the CF?
That's what I would do, and what many others have already done with good results.
Here's what Wiki has to say about denatured alcohol:
Quote from: WikiWiki
Denatured alcohol is not, in itself, a preferred product -- i.e. it is not something which would be normally demanded if given the alternative of normal alcohol. Denatured alcohol and its manufacture are a public policy compromise. The supply/demand for denatured alcohol arises from the fact that normal alcohol (specifically ethanol, suitable for human consumption as a drink) is usually very expensive compared to similar chemicals, being highly taxed for revenue and public health policy purposes (partly as a deterrent). As a result, if pure ethanol were made cheaply available for other useful industrial/commercial purposes (such as fuel, solvents), this would create a temptation or incentive to convert relatively cheaper industrial ethanol for human consumption.
Denatured alcohol provides a solution to permit legitimate use/manufacture of ethanol, whereby cheap ethanol can be made available for non-consumption use without the risk of it being converted for consumption. The process creates a modified ethanol, largely similar to ethanol for most purposes, but is poisonous, thus rendering it unsuitable for drinking. As a result there is no duty on denatured alcohol in most countries, making it considerably cheaper than pure ethanol. Consequently, its composition is tightly defined by government regulations which vary between countries.
The interplay of purposes to reach this compromise can be envisioned as a three-sided triangle:
making ethanol easily available for legitimate industrial/commercial use,
allowing a reasonable price to be achieved by exempting taxation, and
eliminating the possibility of human consumption of this ethanol.
Exceptions to this triangle result in the alternative of heavy regulation, illustrated by the following: in instances where absolutely pure ethanol is needed at a reasonable non-consumption-taxed price (for example, at chemical research laboratories), tight security procedures are required to eliminate the possibility of conversion for human consumption -- specifically, tracking the purchase and distribution of the alcohol, and ensuring compliance of workers who handle the pure ethanol.
So it's not that you need to use denatured because it has specific properties, just that it's probably cheaper than the alternative of using pure acohol that can be taxed for human consumption...
So I finally got around to trying this today and I've learned 2 things about denatured alcohol.
1. It's great at drying out your hands.
2. It melts clear coat. :o
So, it's not that the denatured alcohol pulls out the water as I was told. What the denatured alcohol is doing is removing the damaged clear coat. As I was rubbing the stuff on some of the worse parts of my damaged fender I found that the weave was showing through the clear already. ??? I also found tons on pin holes all over the freakin the place. :-\ Oh yeah, if you're not using a real rag and are using paper towels or something that can fall apart, be very careful. If you rub at a spot long enough to soften up the clear coat, when the alcohol starts evaporating from your towel, the towel will start the grab and will rapidly decay and start fraying. The little fibers that fall off can then become embedded in your clear coat. >:( So, I'm still playing around with it but for now I think I'll take a break and finish it tomorrow.
Pics.
Before Dry:
(http://i37.photobucket.com/albums/e70/erkishhorde/DSC_0003.jpg)(http://i37.photobucket.com/albums/e70/erkishhorde/DSC_0004.jpg)
Before Wet:
(http://i37.photobucket.com/albums/e70/erkishhorde/DSC_0005.jpg)(http://i37.photobucket.com/albums/e70/erkishhorde/DSC_0006.jpg)
After drying, it reverts back to the milky look like in the first two pictures.
After rubbing on denatured alcohol:
(http://i37.photobucket.com/albums/e70/erkishhorde/DSC_0007.jpg)(http://i37.photobucket.com/albums/e70/erkishhorde/DSC_0008.jpg)
I haven't gotten around to re-clearing it yet but I'll post pics once I get around to that.