UV clear coat protection on carbon frame?

Discuss light weight issues concerning road bikes & parts.

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spectastic
Posts: 34
Joined: Wed Jun 24, 2015 8:11 am

by spectastic

i don't like the pj on my tcr, so I would like to strip paint off and apply some kind of UV and clear coat protection. I'd like advice on some options available. UV protection goes without saying. I'm also wondering if it'd be wise to get some kind of resin protection to protect the carbon from rocks. I do plan to use this for some gravel riding. Also, is it necessary to apply the coating via spray application, or do you think I can get away with just painting it on? what are the pros and cons of each? any suggestions for products to use for best finishing result? Thanks

jorisee01
Posts: 364
Joined: Mon May 04, 2015 8:22 pm

by jorisee01

I didn't clear coat my frame but used 303 protectant instead. Apply it every month and your good.

https://www.amazon.com/303-30313-CSR-Pr ... B00KN0UOEE

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by Weenie


TobinHatesYou
Posts: 7050
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

The best rattlecan clearcoats are the 2K ones with the fine vertical mist nozzle and a catalyst that gets mixed when you break a seal through the bottom of the can. Bear in mind these products contain isocyanates and you should never use them without a quality respirator mask (not some shitty N95.) Even with the respirator, you should only spray in an area with really good ventilation (or just do it outdoors.)

Mask off any bits you don't want clearcoated. Spray from between 10-15cm...always start your spray with the can already moving and off the area you want sprayed. 2 passes per coat, wait at least 10 minutes between coats, apply 3 coats since you won't have any primer or paint underneath.

Marin
Posts: 3739
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

You don't need UV protection unless you leave your bike out in the sun 365 days a year like a boat.

2k clear is more or less the same thing as the epoxy matrix the carbon is embedded in anyway, so if your sanded & polished frames looks good enough you can just leave it like that.

When I strip bars or seatposts I usually get a decent finish by sanding with fine grit and then using car polish to finish it off.

wilwil
Posts: 427
Joined: Thu Sep 23, 2010 5:47 pm

by wilwil

If UV was a problem to carbon bikes wouldnt owners of the C64 be in trouble? It looks to me like the tubes on the C64 are raw carbon but could be mistaken.

Vjl
Posts: 31
Joined: Wed Mar 16, 2011 7:14 pm

by Vjl

Armor All regularly.

AJS914
Posts: 4449
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

Armor All - gross. I wouldn't put that greasy silcone spray on anything I own. 303 Protectant is really good.

Feehliks
Posts: 16
Joined: Sun Oct 18, 2020 12:07 pm

by Feehliks

Any further insights about what UV protection carbon requires?

Noting OPEN cycles sell their frames in a ready to paint version with the explicit remark that clear coat was not needed for UV protection.
  • 2019 Specialized Tarmac SW SL6 Red AXS Zipp 303
    2019 Cervelo P3 II Red AXS 1x Zipp 808
    2017 Cannondale Slate Force CX1 stock
    2012 Specialized Tarmac SL2
    2011 Cervelo P3 - under conversion to single speed/fixie
    2009 Cannondale CAAD9 Ultegra

Steve Curtis
Posts: 456
Joined: Thu Jul 31, 2008 12:20 pm
Location: Hampshire UK, Dublin Ireland and Geneva Switzerland.

by Steve Curtis

Just an FYI. 303 protectant Doesn't work.
Project farm on YouTube tested it and it did pretty much nothing.

I always had my doubts about it after using it on my cars soft top.

https://www.youtube.com/watch?v=XXOX4z6uwXo

Start at 11.50 for the uv test.

Catagory6
Posts: 549
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

second vote for 2k
the can doesn't last very long at all, so be prepared to do one coat one day, and the second the next day
and practice on some kind of scrap tubing of something or other. doesn't need to be carbon.
it can go on pretty heavy, and the only way to modulate is to vary the distance
there are some good tutorials on YT. i think ETOE might have a good one

jeanjacques
Posts: 338
Joined: Thu Apr 14, 2016 11:01 am
Location: France

by jeanjacques

Marine varnish (solvant based not water) from hardware store, one or two thin diluted layers. Less than 10g for a complete frame.

Butcher
Shop Owner
Posts: 1227
Joined: Sun Jan 03, 2010 4:58 am

by Butcher

2k left in the refrigerator will allow a day or two longer for spraying. Needs to be warmed up before spraying the next day.

DaveS
Posts: 3135
Joined: Fri Mar 24, 2006 1:26 pm

by DaveS

I only have a bare seat post polished. I put some car wax on it, but I'm going to skip the clear coat.

tjvirden
Posts: 16
Joined: Sun Nov 22, 2020 9:21 pm

by tjvirden

Feehliks wrote:
Tue Dec 08, 2020 1:57 pm
Any further insights about what UV protection carbon requires?

Noting OPEN cycles sell their frames in a ready to paint version with the explicit remark that clear coat was not needed for UV protection.
In short, carbon (to be clear; meaning carbon fibers embedded in a polymer - almost exclusively epoxy-based in the bicycle world - matrix) nowadays doesn't really need additional UV protection for a good service life, when considering bikes & their parts.

That's assuming the (epoxy) resin matrix itself has, at least, reasonable resistance to degradation by UV light as many now do. Any competent producer will use a resin that meets that basic standard, except if the part is specifically designed to be protected from UV (by UV filtering 'paint' for example) and/or they want to use a resin that has particular properties that preclude UV resistance. It is still worth noting that all aromatic polymers, including epoxies, will degrade in UV.

Since the carbon fibers themselves, for practical purposes, do not transmit UV (meaning they absorb it) and are not degraded by it , the resin underneath is unaffected so a carbon composite part will only suffer degradation at its surface as the resin is gradually eroded in between the fibers. Given the fineness (~7μm) and close spacing of the carbon fibres, this is a slow process in the typical conditions that bikes see. Perhaps the best popular example of carbon composite without additional UV protection is done by Koenigsegg with their 'polished carbon' finish; this deliberately exposes the fibers and gives a finish, both in texture,heat transmitttance and aesthetic, that only graphite can. I'm sure it's incredibly tedious to do on such large panels!

northwestern
Posts: 119
Joined: Thu Oct 29, 2015 11:13 pm
Location: Phoenix,AZ

by northwestern

Marin wrote:
Thu Oct 25, 2018 8:16 am
You don't need UV protection unless you leave your bike out in the sun 365 days a year like a boat.

2k clear is more or less the same thing as the epoxy matrix the carbon is embedded in anyway, so if your sanded & polished frames looks good enough you can just leave it like that.

When I strip bars or seatposts I usually get a decent finish by sanding with fine grit and then using car polish to finish it off.
I live in the desert and I was afraid the paint on my Tarmac Nibali would be damaged by the sun. I emailed specialized and they told me the same thing. Unless the bike is kept in the sun all-day, the paint will no not be damaged. They also said that none of these protectants are tested on bike paint, so you might end up damaging the paint yourself.

by Weenie


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