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Old 02-12-05, 10:53 AM   #1
phunkfarm
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stripping paint off carbon fiber frame

I just bought a Lemond full carbon frame that needs painting. What I'd much rather do is strip off all the paint and apply a clear over the carbon for a naked look.

What is the best procedure for doing this without damging the carbon underneath? Is the carbon under a painted frame worthy of being maked? Do they take the care to lay the carbon evenly and straight when they know that paint is going over the carbon? What clear is best to lay over? Is this job too ridiculous to even attempt?

Just wondering what suprises I would find underneath?
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Old 02-12-05, 02:28 PM   #2
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That is a very delicate operation. The carbon would be visually the same as a clearcoated carbon. The precarious thing is how to remove the paint without damaging or touching the fibers. I cannot reccomend a chemical means, but that does not mean it is impossible. Contact a place that deals with carbon fiber construction or the frame manufacturer and ask them if there is a compatible chemical stripper. If it is not, it can soften the bonding agent and compromise the frame.
The other option is to get some finer grit sandpapers. Start with 220 grit and sand lightly while keeping it wet. The water allows the work to come out smoother and keeps the paper from clogging. When you feel like the color is almost off, switch to a finer grit. 400 or so and procede, still wet, and take the remaining color off. Follow that with 600 grit very lightly and dry it off after you rinse it.
Look for scratches that may have been left from the sanding. It is important to remove these as they can be problematic later.
To get the best results for a clearcoat, get some Gelcoat from a fiberglass/carbon fiber finishing supplier and follow its instructions for application. You will not need or want much, but it will come out much better than a paint type clear.
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Old 02-14-05, 08:27 AM   #3
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I suggest you look into high pressure water removal. I'd never heard of this until I was having a frame refinished. The preparation and paint removal was done with this technique.
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Old 02-14-05, 08:55 AM   #4
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I thought the "naked carbon" look was achieved with a cosmetic coating of carbon fiber and a "carbon in the raw" frame is not a candidate for that carbon look, ie. it is meant to be painted.

I may be wrong, but I heard this elsewhere, don't remember where but worth considering before you get too deep into the project??
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Old 02-14-05, 09:05 AM   #5
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Originally Posted by Ebbtide
I thought the "naked carbon" look was achieved with a cosmetic coating of carbon fiber and a "carbon in the raw" frame is not a candidate for that carbon look, ie. it is meant to be painted.

I may be wrong, but I heard this elsewhere, don't remember where but worth considering before you get too deep into the project??
Right,......... wrong.
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Old 02-14-05, 10:35 AM   #6
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Chemical strippers will eat the epoxy out of the carbon and leave a very flexible carbon frame. Sanding works but as said above you do not want to sand into the carbon at all. Probably best left alone but it is your bike.
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Old 02-14-05, 11:10 AM   #7
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OK, then my next option is to powdercoat it.

The construction, again, is Gelcoat over Carbon I found out after a bit of research. Can the gelcoat and carbon withstand the 400 degree temp of the powdercoat ovens without warping?
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Old 02-14-05, 11:21 AM   #8
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I wouldn't put my carbon frame in a 400 degree oven. If I were you, I would scuff the old paint enough to remove the gloss, and respray with auto quality paint and clearcoat.
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Old 02-14-05, 11:28 AM   #9
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You can't powder coat carbon as far as I know. Carbon is an insulator, not a conductor. There will be no way to get the powder to stick on the frame.
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Old 02-14-05, 11:30 AM   #10
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Originally Posted by Ebbtide
You can't powder coat carbon as far as I know. Carbon is an insulator, not a conductor. There will be no way to get the powder to stick on the frame.
Carbon is a fairly good conductor, it's the epoxy that is lousy at conduction.
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Old 02-14-05, 11:37 AM   #11
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Originally Posted by phunkfarm
OK, then my next option is to powdercoat it.

The construction, again, is Gelcoat over Carbon I found out after a bit of research. Can the gelcoat and carbon withstand the 400 degree temp of the powdercoat ovens without warping?
You can't powdercoat CF.
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Old 02-14-05, 01:48 PM   #12
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Find an autobody body shop that does sand blasting with alternative blasting media, specifically walnut shells.

Not only will this ensure that they frame paint only any shop that has this equipment will also have the skilled operator to do the job quickly and safely. Don't try this with normal blasting media, sand, it will probably work but a heavy handed unskilled person might screw it up.
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Old 02-14-05, 05:48 PM   #13
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Look, let's be realistic.

You have a nice frame there (CF is not my cuppa - but each to their own).

What you are talking about here is sanding, grinding, blasting (water! - what the!), burning (with chemicals) a top coats on a very delicate piece of engineering.

DON'T DO IT!

1. There will be MANY opportunities to completely screw your frame if you try this, with an outcome that is not going to look all that good (most CF "nude" frames have a last wrap for show - painted ones don't)*

2. It will take a really long time to do if you sand it, and cost money if you use someone else to do it (and I'll bet they will not guarantee their work).

3. It won't look all that good anyway.

* I have seen it done on Kestrels and Treks - the outcome is not so impressive.

A. Fill any deep scratches and gouges with auto body filler

B. Sand back the frame with progressively finer grades of sandpaper until nice and smooth.

c. Undercoat and topcoat by a reputable frame painter.

You will not be unhappy with the result (especially if you get some replacement decals), and you can pick your favourite colour too.
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Old 02-14-05, 07:23 PM   #14
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3. It won't look all that good anyway.

* I have seen it done on Kestrels and Treks - the outcome is not so impressive.
Trek use to market a nude carbon in a OCLV frame like his Lemond and it's still an option as project one. How it looks is probably a matter of opinion. If he really wants it done Trek is likely the one to ask and they may even do it.
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Old 02-14-05, 08:33 PM   #15
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There is a big difference between that nicely woven carbon fiber that most companies use as a finishing coat and a true "nude" carbon fiber, like on a Calfee (drool!, and I'm not a big CF fan)
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