Fork -is this carbon, and how to repair paint damage?

[robjh]

I have an area of chipped paint on the forks of my Giant TCR1, ca. 2001 vintage, which I have made worse through some heavy-handed bodging on the nearby stuck brake caliper bolt.

The TCR specs reckon that these forks are carbon, but it doesn't look how I imagined. Any thoughts on the picture?

How would I start with repainting these patches? They have quite a rough surface.

 

[fossyant]

Alloy crown, carbon blades possibly. A picture further away would help.

 

[Spiderweb]

A better photo would be good. My initial thought is that you have aluminium oxidisation/corrosion. I would think the area needs sanding back to clean blemish free aluminium before you think about repainting.

 

[robjh]

Alloy crown, carbon blades possibly. A picture further away would help.

This is what the whole thing looks like

 

[robjh]

A better photo would be good. My initial thought is that you have aluminium oxidisation/corrosion.
View attachment 606039

That was the best picture I could get after a lot of trying. But I too thought it looked more like alloy than carbon. Maybe indeed just the blades that are carbon, and there will be a join somewhere near the area shown.

 

[iluvmybike]

looks like it has had a hard life

 

[robjh]

looks like it has had a hard life

A long and varied life, certainly

 

[the snail]

If it's aluminium, you'll need to rub it smooth, and deal with areas where the corrosion is running under the paint, then use a primer designed for alu/non-ferrous metal.

 

[ColinJ]

Is aluminium corrosion like that a safety issue, or just a cosmetic one? (I have noticed similar corrosion on my singlespeed bike.)

 

[fossyant]

Is aluminium corrosion like that a safety issue, or just a cosmetic one? (I have noticed similar corrosion on my singlespeed bike.)

Cosmetic as it self seals. Just looks a blooming mess. Certainly needs treating as the mess can spread.

 

[gbb]

Photo 1, is that near the top of the fork (the crown) or near that taped section midway up the forks in the second photo ?
If it's on the crown, I suppose you have to decide how much the carbon has delaminated from the alloy. I had similar on a Bianchi but the area wasnt big, cleaned it up, painted it, an ok repair.
Itd be good for some more photos, it's not much to go on.

 

[Peugeotrider]

You need to feather out the damaged area with sandpaper and apply a self etching primer over it as it looks like ALU.
Once the self etch is dry, apply a high fill primer and let it dry.
Then rub all down in 800 sandpaper and good for top coat.
Personally....I'd get a car body shop to do it. It won't be that costly to fix.
I'd estimate they will charge u roughly 100 pounds Max.
I'm in a body shop so just my thoughts

 

[Ming the Merciless]

A better photo would be good. My initial thought is that you have aluminium oxidisation/corrosion. I would think the area needs sanding back to clean blemish free aluminium before you think about repainting.
View attachment 606039

I would agree it looks like Aluminium Oxide.

 

[robjh]

You need to feather out the damaged area with sandpaper and apply a self etching primer over it as it looks like ALU.
Once the self etch is dry, apply a high fill primer and let it dry.
Then rub all down in 800 sandpaper and good for top coat.
Personally....I'd get a car body shop to do it. It won't be that costly to fix.
I'd estimate they will charge u roughly 100 pounds Max.
I'm in a body shop so just my thoughts

I quite like the bodyshop idea, but for £100 I could buy a generic new fork - but would then pay more to get a spray in a matching colour.
The alternative, repaint the existing one myself will be cheaper, but with a fair chance of bodging.
A toughie.

 

[robjh]

Photo 1, is that near the top of the fork (the crown) or near that taped section midway up the forks in the second photo ?
If it's on the crown, I suppose you have to decide how much the carbon has delaminated from the alloy. I had similar on a Bianchi but the area wasnt big, cleaned it up, painted it, an ok repair.
Itd be good for some more photos, it's not much to go on.

It's the top, near the crown, on the opposite side from photo 2.