Corrosion - course of action?

slowbike

Whilst fitting some new mudguards to my Allez this week I noticed some bubbling around the crown of the fork.
It's a carbon fork with alloy steerer - so alloy crown too. The rest of the fork is in good condition - the bike is ~6 seasons old and has covered ~9k miles - so it's not "Old" - well - I don't think so anyway.

The corrosion seems to have come from just behind the brake mount - which isn't surprising, it's a joint in the paint and somewhere where the paint could easily be damaged and it has started flaking.

I'm contemplating what I should do with this - at a relatively early stage I guess it would be possible to re-condition the crown - sand back, reapply some primer to seal and finish off with some new paint. I won't be able to match the existing paintwork well - it's Specialized Red - but the forks do have black on them - so a black crown would be easier to achieve without it looking too scruffy.

Thoughts?

svetty

Galvanic corrosion at metal: carbon interface?

Matthewfalle

Sand back, inspect, respray.

No reason at all why you can't get the same red. Why do you think so?

slowbike

Svetty wrote:

Galvanic corrosion at metal: carbon interface?

No - it's where the paint has flaked - so just dirty water getting in. Just around where the brake mounts.

slowbike

Matthewfalle wrote:

Sand back, inspect, respray.

No reason at all why you can't get the same red. Why do you think so?

yup - just toying with if I do that or leave it - but I think it needs doing sooner rather than later (ie the summer when I can ride my carbon bike).

Matching colours is a nightmare - especially as it'll but straight up to the adjacent red - it'll be noticeable. Far simpler to change the colour - and black is on there - so do a black section around the crown which will not be adjacent to other black sections and therefore an exact match isn't required.

Matthewfalle

Slowbike wrote:

Svetty wrote:

Galvanic corrosion at metal: carbon interface?

No - it's where the paint has flaked - so just dirty water getting in. Just around where the brake mounts.

SOunds just like paint flake - sand down, prime, spray.

Matthewfalle

Slowbike wrote:

Matthewfalle wrote:

Sand back, inspect, respray.

No reason at all why you can't get the same red. Why do you think so?

yup - just toying with if I do that or leave it - but I think it needs doing sooner rather than later (ie the summer when I can ride my carbon bike).

Matching colours is a nightmare - especially as it'll but straight up to the adjacent red - it'll be noticeable. Far simpler to change the colour - and black is on there - so do a black section around the crown which will not be adjacent to other black sections and therefore an exact match isn't required.

It's not that much of a nightmare.

Remove fork

Take to paint factor

Buy can of paint

Spray

slowbike

Matthewfalle wrote:

It's not that much of a nightmare.

Remove fork

Take to paint factor

Buy can of paint

Spray

you missed:
see paint join ...

Black is fine - I can change the design a little

jermas

You'll need an acid etch primer to bond to the aluminium.Alternatively, If the area is not noticeable (behind mudguards) you could just remove the bubbling paint and spray with an anti corrosion wax. Supertrol or Comma wax seal dry to a semi-hard finish and will stop further corrosion for years.

slowbike

It'll be visible - although underneath between the forks could be waxed.

Matthewfalle

Slowbike wrote:

Matthewfalle wrote:

It's not that much of a nightmare.

Remove fork

Take to paint factor

Buy can of paint

Spray

you missed:
see paint join ...

Black is fine - I can change the design a little

Why will there be a paint join?

I'm sorry if I sound argumentative but I'm so tired and I may be missing the point.