Bald spot from tire rub. What to use to seal raw carbon?

Discuss light weight issues concerning road bikes & parts.
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Catagory6
Posts: 123
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

ive heard nail polish can be used to clear coat over raw carbon, but i imagine its not very durable for an area of the frame that sees a lot of abuse.

AJS914
Posts: 2042
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

The clear coat should stay on unless the tire rubs it off again.

by Weenie


fromtrektocolnago
Posts: 1001
Joined: Sat Dec 07, 2013 10:15 pm

by fromtrektocolnago

too aggressive with tire selection?
Colnago C-59 (Dura Ace)
Firefly(Ultegra)
Trek 5200(ultegra)

Catagory6
Posts: 123
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

AJS914 wrote:
Sat Dec 23, 2017 6:30 pm
The clear coat should stay on unless the tire rubs it off again.
Well, thats the plan, but what can i use to clear coat the raw carbon?

And to answer the following question, i had broken a spoke a number of times which moved The rim out of true, causing the tire to come into contact with the chain- and seat stays

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MJB
Posts: 172
Joined: Thu Jan 19, 2012 11:17 am
Location: bottom edge of Australia

by MJB

If it's a small coin sized area that is effected then I'd be looking to clean the area with acetone, warm it up with the hair drier and paint on some clear coat automotive touch up paint. A small pot of touch up with an application brush should do the trick nicely. This has worked long term for me on stone chipped chain stays.

If the area is larger or in a highly visble spot and you want to maintian max. cosmetic appearances then look to your local auto panel spray painter or better still an airbrush artist.

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

by AJS914

Be cautious with a hair dryer, you could over do it. Honestly, I don't think a hair dryer is necessary and acetone sounds a bit strong to put on the existing resin.

DamonRinard
in the industry
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Joined: Fri Apr 29, 2011 8:32 pm
Location: Connecticut, USA

by DamonRinard

Structurally, no paint is needed.
Cosmetically, might be nice to touch up.
Damon Rinard
Engineering Manager, Road Bikes
Cycling Sports Group, Cannondale
Ex-Kestrel, ex-Velomax, ex-Trek, ex-Cervelo

Catagory6
Posts: 123
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

DamonRinard wrote:
Sun Dec 24, 2017 12:27 am
Structurally, no paint is needed.
Cosmetically, might be nice to touch up.
its an 11 year old frame. at this point i'm not TOO concerned about a bare spot in the stay-crotch.
but i've heard that carbon absorbs water, so i want to at least seal the area

BikeAnon
Posts: 399
Joined: Sun Mar 02, 2014 6:36 pm
Location: NY USA

by BikeAnon

Any auto clear coat will do.

You can get one of those that have the built in paint brush. Or use spray. Whichever suits your skill level and desire for a finely flat, blended finish.

Me.... I'd probably brush some on, lightly sand it afterwards, then polish it.


I'd also avoid the acetone. The carbon will be fine, but we don't know how the neighboring finish will feel about it. It would probably be fine.


I'd clean it with a degreaser, and then rubbing alcohol. Air-dry. Or blow dry.
Last edited by BikeAnon on Fri Jan 19, 2018 3:26 pm, edited 1 time in total.

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Rick
Posts: 2035
Joined: Sat Aug 29, 2009 4:30 pm

by Rick

Reposting the same info from a similar question about a week or two ago:

Is it just a cosmetic "scratch" or a deep and distinctive "gouge" ?
If a gouge:
Wash the region thoroughly with dish soap and water. Really scrub out the gouge with a nylon or similar brush (toothbrush?).
Rinse thoroughly and air dry.
Masking tape off the surrounding area.
Squeegee some 5 minute epoxy, available at any hardware store down into the defect and smooth off with an old credit card or similar.
Immediately, carefully remove the masking tape. Let cure thoroughly.
5 min epoxy will dry clear, hard as nails, and will hold tight. Other methods work too, but it is difficult to match the hardness and tenaciousness of epoxy.

Or, ....just paint some clear fingernail polish into it and don't worry about it. It probably really won't make a difference to structural integrity or reliability.

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Hellgate
Posts: 99
Joined: Mon Mar 27, 2017 8:49 pm

by Hellgate

Catagory6 wrote:
DamonRinard wrote:
Sun Dec 24, 2017 12:27 am
Structurally, no paint is needed.
Cosmetically, might be nice to touch up.
its an 11 year old frame. at this point i'm not TOO concerned about a bare spot in the stay-crotch.
but i've heard that carbon absorbs water, so i want to at least seal the area
Carbon doesn't absorb water. It's not a sponge.

Sent from my ONEPLUS A5010 using Tapatalk



by Weenie


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