Restoring carbon fibre? **PICS ADDED**

[mikesnowdon]

Hi.

I have an original Easton CT2 Monkeylite bar. I got if from the bay for not too much and its a little bit tatty. Its more tatty than was shown by the seller in his photos but no worries. The clearcoat/lacquer is chipped and not as shiny as it should be. Also the ends of the bar are slightly damaged from either bar ends or lock on grips that have been over tightened.

To fix the damaged ends I thought I could use some 2-part epoxy resin. The plan would be to cut the tops off a pair of bar plugs (or something similar) and push them inside the ends of the bar about 15/20mm. Then pour in the resin until flush with the end of the bar and allow to set. Opinions?

For the lacquer I'm a little unsure. Been reading up on the net on restoring CF and mostly found car bodywork forums where people need to restore a CF bonnet. The general idea is to use a very light abrasive to (wet&dry) buff out any marks or chips and smooth out the whole area. Then re-lacquer. I have no idea if there is a certain kind of lacquer I should use though.

I thought it was worth asking here as some of you may have restored old skool CF bikes (such as the Miyata in this months BoTM) and might be able to advise?

I'll email Gil_M about new decals.

(Need any pics just shout)

TIA!

 

[hamster]

I've not done any carbon bikes but have repaired racing catamarans - the plug plan sounds fine, but I'd add some microfibres to the epoxy to give it some strength. Do it one end at a time and keep the bars end-down so the epoxy pools and doesn't run.

Microfibres are available from most marine chandlers.

 

[Neil G]

Hacksaw + bin best for carbon bars lol

TBH I'd be very wary of carbon bars that have been damaged....can never tell how string the material is once damp has go into the fibres

 

[Crayons]

I second that sentiment – thought the lacquer was cracked on my carbon bars, turns out it was the bars themselves – won't go near the stuff now.

 

[dorsetbikeloving]

I agree with Hampster. although tricky Carbon can be repaired if done correctly. adding the fibres will add strength and applying heat will help to force the strength, just a hairdryer will do.

 

[squiffy]

hi i work with carbon you need to bond the ends in with glue such as scotchweld (3m 9323) abrade both pieces clean up with acetone or brake cleaner and gentley heat for a bit to cure. as for the surface finish fine wet and dry 1200 grit upwards and then carbon polishes well with fine cut or finesse polish and should shine like a mirror with enough elbow grease!!!

 

[mikesnowdon]

hi i work with carbon you need to bond the ends in with glue such as scotchweld (3m 9323) abrade both pieces clean up with acetone or brake cleaner and gentley heat for a bit to cure. as for the surface finish fine wet and dry 1200 grit upwards and then carbon polishes well with fine cut or finesse polish and should shine like a mirror with enough elbow grease!!!

You sound like you know your stuff when it comes to CF.

As far as I can tell the actual structure of the bar is sound, its just the lacquer that's chipped. And the minor damage at the ends is minimal and well away from any high stress areas. I'll follow your advice on repairing the ends and restoring the shine. What about some alloy tube inserts about 12 pressed inside the ends of the bar and glued with the glue you recommend?. Once I have that done what would be a good lacquer to apply for protection?

And finally, in your expert opinion would you say the bar is safe to ride?

 

[ragnar1984]

What about some alloy tube inserts about 12 pressed inside the ends of the bar and glued with the glue you recommend?.

AFAIK some manufacturers actually do just that to reinforce their bars at the ends and in the area where brake levers and shifters clamp on.

Once I have that done what would be a good lacquer to apply for protection?

I have used acrylic laqcuers when touching up chips.
http://www.halfords.com/webapp/wcs/..._productId_210069_langId_-1_categoryId_165495

Some words of warning:
When wet&dry sanding, go very lightly. If the grit you are sanding off goes black, you're down to the carbon.
Go easy with heating. Some resins undergo glass transistion (become very hard and brittle) as low as 65ºC. It should never be so hot that you cannot touch it. And that precludes the use of power tools like buffing wheels.

 

[mikesnowdon]

Ok thanks for the info.

There is a local engineering company that I can ask to make me some tubular alloy inserts. Something like 1" long. Maybe I could freeze the inserts before fitting them so they expand a little? I'll could then use a syringe to fill all the gaps with the glue recommended by squiffy. To cure the lacquer I'll just leave the bar in the airing cupboard over night. Its warm and dry in there but not too hot. I wont use any power tools on this, just lots of effort with wet & dry.

Should I post some pics of the damaged areas for expert opinion?

 

[ragnar1984]

Yes, some pictures would be good.