Deep scratch in carbon frame

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Deep scratch in carbon frame
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flag uphilarious
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Posted: Feb 22, 2016 at 18:32 Quote
*I searched around a bit, but couldn't find any good answers where carbon was actually exposed*

I have a quite new carbon rocky mountain instinct that just recently got a nasty scratch on the top tube that goes down just far enough that I can see a little but if carbon. I am ok with the scratch, I just want to make sure that it is ok to have the carbon exposed and won't cause any damage. I've heard about covering it up with clear nail polish, should I do that?
flag Andr0id
Posted: Feb 23, 2016 at 5:34 Quote
I'm no bicycle engineer or carbon expert, but I work with composite aircraft blades. We use a product called: Huntsman Araldite 2012 Fast Setting All-Purpose Epoxy. Its $20 on amazon, tinsel strength is amazing, check specs on the huntsman website. Watch some youtube videos on surfboard repair, almost the same thing. Don't use nail polish.
flag captaingrumpy
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Posted: Feb 23, 2016 at 11:44 Quote
Andr0id wrote:
I'm no bicycle engineer or carbon expert, but I work with composite aircraft blades. We use a product called: Huntsman Araldite 2012 Fast Setting All-Purpose Epoxy. Its $20 on amazon, tinsel strength is amazing, check specs on the huntsman website. Watch some youtube videos on surfboard repair, almost the same thing. Don't use nail polish.

Nail polish is just to seal and protect the clear coat, which itself protects the carbon fibers.

For deep scratch you need something with strength. Can you share a photo?

The strength in your frame comes from the carbon fibers. If they are nicked you can't squeeze glue into the scratch because the fibers are no longer continuous. Need to fill nick and then lay new fiber over it.

Bonding is Modern Science, meaning it confounds modern material scientists. Tons of specifics that matter, including surface prep, cure time, cure temperature and sealant. Not a matter of squirting some epoxy into the scratch.

Here are the specs for the above huntsman araldite. See all the conditions where it is not strong?

http://www.adhesivehelp.com/productdatasheets/huntsman-a2012.pdf

Send an email to Rocky and see what they say. If you have a significant nick you should probably send it to Calfee.
flag RunsWithScissors
Posted: Feb 24, 2016 at 15:17 Quote
uphilarious wrote:
*I searched around a bit, but couldn't find any good answers where carbon was actually exposed*

I have a quite new carbon rocky mountain instinct that just recently got a nasty scratch on the top tube that goes down just far enough that I can see a little but if carbon. I am ok with the scratch, I just want to make sure that it is ok to have the carbon exposed and won't cause any damage. I've heard about covering it up with clear nail polish, should I do that?

It's hard to form an opinion without a pic, but if the scratch doesn't go very deep into the carbon you may have nothing to worry about. Carbon fiber is amazingly strong. The simple fact that you can see the carbon is no reason to panic. Depending on the situation you may be able to ignore it, or you may be able to just buy a little bit of carbon cloth and some epoxy and do a repair. As Captaingrumpy mentioned, Calfee (among others) does carbon repair. One of the many advantages of carbon fiber is its repairability. Having said that, if you DO decide to repair it yourself, do a little research and choose an epoxy that has a high UV tolerance. Sunlight kills some epoxies.
flag uphilarious
O+
Posted: Feb 25, 2016 at 17:52 Quote
The scratch doesn't go into the carbon at all, it's just a little bit of it exposed at the deepest part of the scratch, so I have no reason to believe that the structural integrity of the carbon has been hindered at all. I'm just worried about water or something getting under the paint or something will damage the carbon some how. I can post a picture later tonight, and I emailed rocky mountain the other day but haven't heard back yet.

Thanks for your help guys!
flag RunsWithScissors
Posted: Feb 25, 2016 at 18:00 Quote
uphilarious wrote:
The scratch doesn't go into the carbon at all, it's just a little bit of it exposed at the deepest part of the scratch, so I have no reason to believe that the structural integrity of the carbon has been hindered at all. I'm just worried about water or something getting under the paint or something will damage the carbon some how. I can post a picture later tonight, and I emailed rocky mountain the other day but haven't heard back yet.

Thanks for your help guys!

Based on what you've posted I would quite literally ignore it on my bike. Total non-issue. It's a bike. You ride them, sometimes crash them, and in the process they get scratched. Carbon is crazy strong. It's used to make large commercial aircraft primary structures, scuba tanks, natural gas vehicle tanks. Regarding paint, how often do you see scratched bikes with patches of paint peeling off? I've seen a few, but not very many. Sometimes a scratch is just a scratch. Don't worry about it. Go rideSmile
flag captaingrumpy
O+
Posted: Feb 26, 2016 at 9:02 Quote
RunsWithScissors wrote:
uphilarious wrote:
The scratch doesn't go into the carbon at all, it's just a little bit of it exposed at the deepest part of the scratch, so I have no reason to believe that the structural integrity of the carbon has been hindered at all. I'm just worried about water or something getting under the paint or something will damage the carbon some how. I can post a picture later tonight, and I emailed rocky mountain the other day but haven't heard back yet.

Thanks for your help guys!

Based on what you've posted I would quite literally ignore it on my bike. Total non-issue. It's a bike. You ride them, sometimes crash them, and in the process they get scratched. Carbon is crazy strong. It's used to make large commercial aircraft primary structures, scuba tanks, natural gas vehicle tanks. Regarding paint, how often do you see scratched bikes with patches of paint peeling off? I've seen a few, but not very many. Sometimes a scratch is just a scratch. Don't worry about it. Go rideSmile

Agreed. Fill the scratch with nail polish and call it good. It stops the clear coat from delaminating (water gets into the scratch and under the clear.) I have used "Wet 'N Wild" brand "Gel" and it is really tough (+ I like the name.)
flag uphilarious
O+
Posted: Feb 26, 2016 at 23:01 Quote
Thanks guys, I just had it in the shop today and the guys there said it isn't carbon but a protective layer so I'm all good. Thanks for the help!
flag Devjben
O+
Posted: May 19, 2018 at 9:44 Quote
I hate to bring up an old thread, but it seems to be the most relevant.

Yesterday after I finished some good riding I noticed several scratches on my top tube, I also noticed some grinding on the seat post. The scratches are definitely deep and penetrated the pain. I think the damage was caused during my shuttle ride.

I’m just looking for advice, what to do, if I should be worried about the carbon fiber or not.

I took photos but have no idea how tonshare them through this site >.
flag xaos
Posted: May 19, 2018 at 11:18 Quote
Devjben wrote:
I hate to bring up an old thread, but it seems to be the most relevant.

Yesterday after I finished some good riding I noticed several scratches on my top tube, I also noticed some grinding on the seat post. The scratches are definitely deep and penetrated the pain. I think the damage was caused during my shuttle ride.

I’m just looking for advice, what to do, if I should be worried about the carbon fiber or not.

I took photos but have no idea how tonshare them through this site >.

It is a none issue if the carbon is simply exposed, possibly 10 years down the line you could have some minor UV damage but wouldn't worry about water or anything else. A quick easy solution would be get a matching paint pen to go over it that being said I really wouldn't worry and personally would ignore it. If it is more then just the paint that was scratched off an you actually have a significant amount of carbon damage (more then a 1 mm deep) then I might start to have some concerns and want to get it checked out. That being said those spots are not as susceptible to cracks forming or structural failure as say the seat stays, drop outs, or head tube downtube intersection. If you can post photos here or on you profile would help a lot in determining the extent of the damage.
flag Devjben
O+
Posted: May 19, 2018 at 18:24 Quote
I uploaded some photos to an Album on my account, possible you can check them out there?
flag xaos
Posted: May 20, 2018 at 14:56 Quote
Those top tube scratches are absolutely a none issue although a bummer on such a fresh bike! I cant see super well on the seat tube one, it looks a little deeper but still not much of a concern anywhere and in that particular area a complete none issue too.

I would suggest you get some protective tape and spend a little time covering up places that often get scuffs down tube, top tube, where the rear wheel goes through the seat stays and chain stay, back of the seat tube, any cable rub points, where your rear disc rotor might hit when putting the rear wheel in and out, where your water bottle might touch, and anywhere a bike rack might grab your bike etc. Your can get fairly pricey custom cut kits online or I would just get something off amazon search 3M protective film and cut it out for what you want, and have some left over as you find spots that are getting abrasion.
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