paint off carbon

[tsarpepe]

This might have been covered in some archived thread, but my search produced nothing. So, with advance apologies, here is the question: how do you strip paint + clearcoat from carbon fiber without damaging the latter. I have a custom-painted seat post (De Rosa logo), which won't go down into the seat tube. It is the extra paint + clearcoat that prevents it. I need to lower it by about an inch, which means that this is how much of the custom paint I need to strip in order to do it. I've heard that chemicals are a no-no. So, what are my options? Do I have a safe option?

[sokyroadie]

Sure,

Sandpaper, Water, Dust Mask if doing dry.

Mask off the area you want to protect with tape (several layers) and have at it. I would start with a 400 grit automotive body work sandpaper and go slow, you can do wet or dry depending on which works the best. You may need to go to a finer grade as you get close to the carbon, but I bet you can leave a little paint and it will fit.


Jeff

PS - I am not a painter so YMMV - but I have done this several times with good success.

[wasfast]

Especially for a seatpost, handsanding is recommended. There's an easy visual indicator too. The clear coat will leave white dust as you remove it. The carbon will be black dust. Use silicon carbide paper (black wet-n-dry).

I'd use 150 to take off the bulk and then work up a couple grits provided you want to strip it completely.

Alternatively, if you just want to remove enough to allow easier insertion in the frame, put a couple wraps of masking tape around the boundary above where you want to stop. Measure the seatpost diameter before any sanding with calipers and do it in 3 or so places as it's not uncommon for the seatpost to be eggshaped.

Sand the area shoeshine style all around with 220 or 320 grit and check the diameter as you go. Likely, you'll not need to go all the way to the carbon. Most of the clear coats are pretty thick relatively speaking.

[whforrest]

just overhauled my ottrot and seatpost, fork last summer.

i learned this from painters who work with carbon in the auto industry. (carbon hoods, etc.)

i would only recommend 800 grit when sanding the paint on carbon. (especially for a seatpost)

it takes a little longer than 300 grit, once the paint color is removed than you will still have a little film over the carbon and you can see this in many different light angles.

[tsarpepe]

Thanks, guys. This is really helpful.

[happycampyer]

whforrest did an amazing job refinishing his Ottrott (although I still think that he shouldn't have sanded off that last "t" ;) ).

http://forums.thepaceline.net/showthread.php?t=65633

That refinishing job is pro-fessional.