Carbon fiber epoxy repair??

Tyxpx

I have a Defy with a ISP that has some peeling of the clear coat. It is where the clamp is so it hasn't seen much UV. I can NOT feel any fibers. What would I be able to use to repair this? Possibly even something that I can use and sand down, and use to go over spots that have any bubbles or anything.

539C1010-69CC-40E6-BB5A-8779051F56F9 by Kevin Edge, on Flickr

613DAB14-A0CE-456D-BBD3-7B3DA8EEF196 by Kevin Edge, on Flickr

pinno

I repaired a crack in a seat tube near the clamp once (still going) but that looks proper f**ked.

There are dedicated cf repairers out there.

Tyxpx

I have found a few kits for carbon fiber but they all come with some carbon, and a few different things to mix and cost a lot. I was hoping there was something that was just for epoxy repair that would look nice as well. I really dont want to use nail polish clear coat, especially for the seat post area.

crankycrank

Find a local (if possible) CF supplier near you and bring in the seatpost for their advise on the best resin to use. Hopefully they will sell smaller quantities. Some online suppliers will also have tutorials and good info. as well. Also check YouTube.

pinno

Is a repair economically viable?

imposter2.0

It's just the clear coat lifting off. Do as you mention in the first post - rub it down, re-apply some clear coat. You might need some advice on which particular type of clear coat to use - and maybe how best to apply it, but I can't see any other issue. It certainly isn't f*cked..

pinno

Imposter wrote:

It's just the clear coat lifting off. Do as you mention in the first post - rub it down, re-apply some clear coat. You might need some advice on which particular type of clear coat to use - and maybe how best to apply it, but I can't see any other issue. It certainly isn't f*cked..

You should go to Specsavers.

imposter2.0

Pinno wrote:

Imposter wrote:

It's just the clear coat lifting off. Do as you mention in the first post - rub it down, re-apply some clear coat. You might need some advice on which particular type of clear coat to use - and maybe how best to apply it, but I can't see any other issue. It certainly isn't f*cked..

You should go to Specsavers.

Personally, I think you should. There's nothing structurally wrong with that at all..

pinno

Imposter wrote:

Pinno wrote:

Imposter wrote:

It's just the clear coat lifting off. Do as you mention in the first post - rub it down, re-apply some clear coat. You might need some advice on which particular type of clear coat to use - and maybe how best to apply it, but I can't see any other issue. It certainly isn't f*cked..

You should go to Specsavers.

Personally, I think you should. There's nothing structurally wrong with that at all..

My concern was that if the post itself has been pinched and that's why the lacquer is the way it is - i.e, that there is an underlying crack.
If you look at pic 1, at the bottom of the abrasion - to the left, going at a 40 degree angle, what's that?!

imposter2.0

Pinno wrote:

If you look at pic 1, at the bottom of the abrasion - to the left, going at a 40 degree angle, what's that?!

Presumably that's the line where the ISP mast was clamped. Tapping around it with a coin or similar will tell you if there's anything to worry about or not...

Matthewfalle

if the carbon underneath is sound Araldite & rub down then, if necessary, black touch up paint on top

#doneproperlyyouwon'tnotice

sungod

if you are 100% certain damage is non-structural i suggest do as imposter says

once you've removed the peeling coating, degrease the area with acetone or isopropyl alcohol

mask the surrounding area with tape, then apply a decent clearcoat

fwiw i used u-pol up0804 to refresh the clearcoat on an ax seatpost (it gets installed/removed a few times each year for travel and the old coating gradually wears due to the tight fit) it's proven extremely tough and durable, several trips with it and not a hint of peeling

use multiple dusting coats to gradually build up the required thickness

https://www.u-pol.com/files/2725/up0804-TDS-EN
https://smile.amazon.co.uk/UPol-Power-C ... 009G1AU3Q/

Tyxpx

Pinno wrote:

Is a repair economically viable?

If you mean shipping it to a repair shop, then no. I do not think it needs a shop repair. It looks to be just cosmetic. I am building a bike and taking every single screw out, every bearing out, and cleaning and servicing everything. I have parts all over the floor and about 45 pieces of bike all over, haha. I just want to do all that stuff while the bike it totally apart.

Imposter wrote:

It's just the clear coat lifting off. Do as you mention in the first post - rub it down, re-apply some clear coat. You might need some advice on which particular type of clear coat to use - and maybe how best to apply it, but I can't see any other issue. It certainly isn't f*cked..

That is what I am looking for, the RIGHT epoxy to use.

Pinno wrote:

Imposter wrote:

Pinno wrote:

Imposter wrote:

It's just the clear coat lifting off. Do as you mention in the first post - rub it down, re-apply some clear coat. You might need some advice on which particular type of clear coat to use - and maybe how best to apply it, but I can't see any other issue. It certainly isn't f*cked..

You should go to Specsavers.

Personally, I think you should. There's nothing structurally wrong with that at all..

My concern was that if the post itself has been pinched and that's why the lacquer is the way it is - i.e, that there is an underlying crack.
If you look at pic 1, at the bottom of the abrasion - to the left, going at a 40 degree angle, what's that?!

I do not think it compromised the integrity of the seat post. Tap test sounds good. I do not see and cracks inside the tube, and no creaking or anything from the post. Besides that I will be cutting some of it off anyways and the clamp will now be putting pressure on a different part of the post.

Matthewfalle wrote:

if the carbon underneath is sound Araldite & rub down then, if necessary, black touch up paint on top

#doneproperlyyouwon'tnotice

Matthewfalle wrote:

if the carbon underneath is sound Araldite & rub down then, if necessary, black touch up paint on top

#doneproperlyyouwon'tnotice

I will look into these. Thank you!

sungod

Tyxpx wrote:

...
That is what I am looking for, the RIGHT epoxy to use.
...

imo it's not epoxy you want

epoxy is the binder for the fibres, however you are saying it's only the coating that is damaged, which isn't usually an epoxy

epoxy generally has poor resistance to uv and over time it degrades (though you can get uv resistant epoxies)

that's one reason there's a gel coat or clear coat applied over the top to protect the epoxy, typically also gives a better appearance long term (stays clear and shiny)

Tyxpx

sungod wrote:

Tyxpx wrote:

...
That is what I am looking for, the RIGHT epoxy to use.
...

imo it's not epoxy you want

epoxy is the binder for the fibres, however you are saying it's only the coating that is damaged, which isn't usually an epoxy

epoxy generally has poor resistance to uv and over time it degrades (though you can get uv resistant epoxies)

that's one reason there's a gel coat or clear coat applied over the top to protect the epoxy, typically also gives a better appearance long term (stays clear and shiny)

So what is it that I am looking for to repair this? Thought it was more than just a clear coat since it seems a bit thick.

darkhairedlord

Looks buggered. Find a length of aluminium tube and reform to approximately the same as the inside of the ISP. Coat liberally with epoxy and slide it in. That should reinforce the post or perhaps just make it worse.

sandyballs

Matthewfalle wrote:

if the carbon underneath is sound Araldite & rub down then, if necessary, black touch up paint on top

#doneproperlyyouwon'tnotice

I tried this a couple of years ago on a seatpost from the normal Giant TCR frame, exactly same design and carbon layup. As soon as any pressure was applied the araldite split away. I was lucky and just bought a new seatpost.

OP, good luck!

pinno

darkhairedlord wrote:

Looks buggered.

Yes.

Alejandrosdog

I can't honestly tell from the picture but if you have any doubts at all chuck it out. The cost of a seat post is so low its barely worth investing money for materials, a repair or postage.

imposter2.0

Alejandrosdog wrote:

I can't honestly tell from the picture but if you have any doubts at all chuck it out. The cost of a seat post is so low its barely worth investing money for materials, a repair or postage.

It’s an ISP...

Alejandrosdog

Imposter wrote:

Alejandrosdog wrote:

I can't honestly tell from the picture but if you have any doubts at all chuck it out. The cost of a seat post is so low its barely worth investing money for materials, a repair or postage.

It’s an ISP...

oh! in which case thats a bit of a pisser

davebradswmb

sungod wrote:

Tyxpx wrote:

...
That is what I am looking for, the RIGHT epoxy to use.
...

imo it's not epoxy you want

epoxy is the binder for the fibres, however you are saying it's only the coating that is damaged, which isn't usually an epoxy

epoxy generally has poor resistance to uv and over time it degrades (though you can get uv resistant epoxies)

that's one reason there's a gel coat or clear coat applied over the top to protect the epoxy, typically also gives a better appearance long term (stays clear and shiny)

Sorry to pick up on this late, but this is rubbish.

The original clear coat will probably be epoxy. Most epoxy resins are yellow and tend to go more yellow with time, so you have to source the right epoxy or your repair will look a bit ugly. This is what I would use, but you are having to buy a lot for a very small repair.

My experience is not with bikes, but I have been paddling and repairing carbon/epoxy slalom kayaks for a long time now. These are stored outside and I haven't noticed any breakdown due to UV. When repairing the boats I use the same epoxy for the clearcoat as the layup, it isn't ideal but slalom kayaks end up looking pretty battered fairly quickly anyway, so a bit of yellowing in the epoxy isn't such a big issue.

Araldite will do the job perfectly adequately, but it will be yellow. I would be more concerned about the potential damage the clamp is doing to the structure of the post though, this looks to be the result of poorly fitting components.

sungod

davebradswmb wrote:

Sorry to pick up on this late, but this is rubbish.

The original clear coat will probably be epoxy. Most epoxy resins are yellow and tend to go more yellow with time, so you have to source the right epoxy or your repair will look a bit ugly. This is what I would use, but you are having to buy a lot for a very small repair.

My experience is not with bikes, but I have been paddling and repairing carbon/epoxy slalom kayaks for a long time now. These are stored outside and I haven't noticed any breakdown due to UV. When repairing the boats I use the same epoxy for the clearcoat as the layup, it isn't ideal but slalom kayaks end up looking pretty battered fairly quickly anyway, so a bit of yellowing in the epoxy isn't such a big issue.

Araldite will do the job perfectly adequately, but it will be yellow. I would be more concerned about the potential damage the clamp is doing to the structure of the post though, this looks to be the result of poorly fitting components.

what i posted was correct, if you think it's 'rubbish' you need to go away and get an education, pick up some manners too while you're at it

like i said, epoxy in general has poor uv resistance, which is why a gel coat/clear coat is used to protect it from degradation, that may be an epoxy formulated for uv resistance, or it can be one of the many other types

the one you link to is uv resistant, exactly in line with what i wrote"you can get uv resistant epoxies", so you agree with me

that's good, because unless it's a specifically uv resistant epoxy, you don't use it for coating...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5459211/
https://ws680.nist.gov/publication/get_ ... _id=101103
https://www.westsystem.com/instruction- ... -coatings/
https://www.aeromarineproducts.com/poly ... oxy-resin/

Alejandrosdog

Popcorn anyone?

darkhairedlord

It looks like it's been ridden in the rain.
Shove a broom handle and plenty of no more nails down it.

pinno

darkhairedlord wrote:

...no more nails...

Pricey that stuff.

darkhairedlord

Pinno wrote:

darkhairedlord wrote:

...no more nails...

Pricey that stuff.

Tube of resin anchor, even better.

pinno

darkhairedlord wrote:

Pinno wrote:

darkhairedlord wrote:

...no more nails...

Pricey that stuff.

Tube of resin anchor, even better.

Find a 'mop stick' that fits, paint it black.

darkhairedlord

Pinno wrote:

darkhairedlord wrote:

Pinno wrote:

darkhairedlord wrote:

...no more nails...

Pricey that stuff.

Tube of resin anchor, even better.

Find a 'mop stick' that fits, paint it black.

Ride a bit more out of the saddle.

Tyxpx

All great suggestions. I may just hack it off and go completely seat less. A pointy stick is pretty good motivation to keep at it with power peddles and not sit and rest like a sissy.

Alejandrosdog

Tyxpx wrote:

All great suggestions. I may just hack it off and go completely seat less. A pointy stick is pretty good motivation to keep at it with power peddles and not sit and rest like a sissy.

A proper sissy would lube the broomstick. Crack wax might be appropriate.