Scratched/chipped carbon fiber ice tools

[psychobikere]

So how much scratching/chipping is too much? I have only used these tools for one season, and they seem to have shown a lot of wear. I don't have much experience with other carbon fiber tools, but I know that if my carbon fiber bikes looked this bad, I would think twice about riding them. Should I be concerned about this? Or do my tools look like everyone else's?

 

 

[Bob Loomis]

Hi Psychobikere,

 

I have used BD carbon fiber tools for some years (the original Cobras, and the new Cobras) and like anyone, have various scratches, etc., to my tools. I am no expert (no engineer or materials professional), but from what I have been able to learn, if the scratches are cosmetic, then the tool's shaft is fine. But if the scratches run deep (ex., when you run your fingers over the scratches are you detecting scratches that are more like deep gouges), then unless repaired, the tool may be structurally suspect. I say "may be" because it would depend on the nature and extent of the gouges. Fortunately there are fiberglass repair kits (any marina or marine supply place will do) if you want to hold onto the tools and not retire them. If the scratches are cosmetic then perhaps wrap them in tape to prevent further scratching. I defer to others with more knowledge.

 

Cheers,

 

Bob Loomis, Spokane, WA.

Edited January 27, 2010 by Bob Loomis

[psychobikere]

Thanks Bob. I do have some gouges in the tools, the worst being shown in the top picture. I am just pretty surprised, because I don't do much mixed climbing at all. Needless to say though, the thought of retiring a set of $600+ tools after one year is a little too much for me.

[t_rutl]

they look like mine...maybe even in better shape

 

ask BD about their "curb test"...they have intern beat the shaft 100 or so times against a curb then flip it and smash the other...it is then brough in and still passes the strength tests for certification

 

you're good but if you're still concerned you can send it to BD and they eval it for free

[pdk]

Its hard to tell in your top photo, but the scratches and chips in the lower photo appear cosmetic. There is a outer clear coat layer on the new cobras that tends to chip off. This is not carbon fiber and it is not structural. The old cobras don't have this clear coat.

 

You should be able to distinguish this clear outer layer from the inner carbon fiber part of the tool. If you have damage to the carbon fiber part, I'd agree that you should consult BD.

 

My tools look like yours as well. The outer clear coat has lots of chips in it. The carbon underneath is much stronger and hasn't even scratched on my tools.

 

I thought this was a 1st generation problem only, but I guess not if your tools are new.

 

 

 

 

 

Edited January 28, 2010 by pdk

[rob]

So, my limited knowledge is mostly from carbon bikes but I think the idea is the same: with carbon fiber anything, you want to make sure you haven't scratched through the epoxy layers. Even if you haven't scratched the carbon fiber cloth underneath, the entire structure can be suspect if the bonding/laminate epoxy is scratched and damaged. Not sure if you can tell from a photo.

 

You can use a coin to inspect for delaminating...we do this on bikes. If you tap around the suspected damage and undamaged parts with a coin, you can hear a sort of hollow "dead" tone. That's bad.

 

here is a good article on inspecting carbon fiber composites -- bike related, but the technology is the same (i'm assuming.)

 

[Dane]

No worries...nothing compared to the curb test.

Seriously I saw some of the curb test Cobras this week at the BD factory and You are good to go. It is only cosmetic and nothing to repair.

 

I'll post a picture of one of their "test" tools when I get time later in the week.

 

I ride Cervello and S works frames and the major differenece is you have a solid handled tool. It is not hollow. Bike frames would be toast if they looked like that.

[rob]

ahh, i guess that makes sense. Interesting. I guess it's not the same at all!

 

What's underneath the handle? Is the carbon there just to provide stiffness? Makes sense, ice tools get pretty banged up.

[psychobikere]

That's good to hear about the curb test. That's kind of what I was hoping to hear. My knowledge of carbon fiber is also limited to bike frames, which is why I have been worried about my tools. But Dane, if I understand you correctly, you are saying that the shaft on the cobras is NOT hollow? I was under the impression that it is...

[Dane]

Shit...now that I think about it ...yes, they are hollow and pure carbon... but it isn't anything as thin as a bike frame. And I do remember seeing a sectioned Cobra shaft some where so my mistake, they are indeed hollow.

 

I got inundated with BD info/history of tools/shafts and picks this week and can't be trusted unless i have a picture of it.

 

I know it isn't the old technology of carbon wrapped over aluminum which could be a problem and don't survive the curb test for long.

Cobra I am told goes till the guy's arms wear out.

 

 

(edited to correct my stupidity)

[psychobikere]

Thanks for the input everyone. I'm going to give BD a call tomorrow and see what I can learn. I'm sure my 150lbs doesn't put the tools anywhere near the stress levels that BD's testing does, but I'd like to hear what they have to say. I'll post whenever I get in touch with someone.

[nhluhr]

I did my B.S. in Materials Science and for the most part, so long as the product isn't engineered to the limits of strength/mass (like a Tour de France bicycle frame), carbon fiber products can take a LOT of damage to the matrix (the clear part) and not be affected. Once the damage appears to be reaching into the reinforcement (the fibers), then you should begin worrying.

[Dane]

Pictures of a current Cobra shaft weigh is 154 grams. Or 158 g = 5.57328 oz!

 

 

Bottom end

 

top end

[psychobikere]

Thanks Dane! Yeah I'm not too worried anymore. I just thought it was sort of an obvious thing that I couldn't find much discussion on so I thought I'd throw it out there.

[AR_Guy]

(Aerospace Engineer here with some experience in carbon fiber aircraft parts).

 

Generally, if the scratch is only in the outer clear coat / epoxy layer and the fibers aren't broken, you're fine. Blend out the scratch with super fine sand paper, being sure to NOT get into the fibers, clean the area and fill with epoxy resin and you're good to go to restore the cosmetic appearance.

 

With composites of any kind (carbon fiber, FG, etc) the matrix (plastic resin) is there to support and hold the main load bearing members (the carbon or glass fibers) in place and to keep them from buckling under compression loads.

 

Ditto the mention above on the 'tap test'. If there's delam as indicated above (the hollow sound), then there's a major structural issue.

 

 

[G-spotter]

Shafts do break sometimes, with unpleasant consequences:

 

http://ianparnellphotography.blogspot.com/2009/12/winter-warning.html