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Prepping carbon frame. Epoxy necessary?

Old 05-14-16, 03:27 PM
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pressed001 
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Prepping carbon frame. Epoxy necessary?

Hello,
I picked up a Kuota Kredo for a deal because the clear coat was literally falling off. If you ask me, that is what you get for storing your $6000 bike outside for 7 years.... Doh! So anyway. I got it for a deal and am prepping the frame to be painted. I have sanded most of the clear coat off and in some areas I am down to the carbon (just a couple small areas). In this case, can I just prime and paint over the carbon or is a layer of epoxy necessary between paint and carbon?

Tomorrow I will finish the sanding with 300 then 600 grit paper. Today I only made it to the 250 grit.

Build photos will be updated as it progresses and can be seen here.







And that is a typical swiss basement BTW.

Paint will be a very nice orange and will also be applied to the stem/handlebar/seat post/and the dura ace c24 rims (all of which have clear coat failing):

Last edited by pressed001; 05-15-16 at 08:46 AM.
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Old 05-14-16, 03:42 PM
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dksix
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I'm not sure about the epoxy but do feel it's better to stop at about 220 grit for surface prep, paint needs something to adhere to and 600 grit leaves the surface awfully slick.
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Old 05-14-16, 03:53 PM
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Typically a Gel Coat is sprayed into the mold 2nd, after the Mold release, then the Cloth laid on top..

was that done in a wet Layup or Pre Preg?
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Old 05-15-16, 03:06 AM
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I'm not sure about the epoxy but do feel it's better to stop at about 220 grit for surface prep, paint needs something to adhere to and 600 grit leaves the surface awfully slick.
Surfaces prep for paint / clear (if my memory serves me correct) stops @ 400 when shooting base/clear urethane. That should be enough tooth, yet a smooth base. If you stop @ 250, you will see sanding marks through the clear.
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Old 05-15-16, 08:05 AM
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I felt the same after finishing today with the 240 grit. The carbon looks pretty smooth yet with enough of a surface for paint to adhere well to. I will however look further into this as it seems to be a point of concern. I will not be doing clear coat only which I think will make the 240 ok. Plan is for a layer of primer, at least one layer of color, then one of clear. I am not sure and will have to ask the paint shop once I find one.

I have decided against painting the rims the same orange. Instead I thought it would be very cool to get the dura ace hubs orange anodized to match the frame color. Is this even possible (after disassembly of course)? I plan on removing the cable holders from the frame by drilling the rivets and having them black anodized. They look rough now after my sanding job and I don't want them painted over.

So here we are today:







Fietsbob, I don't know how Kuota made the frame but thanks for the input!
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