Respray job

[Half-Fast Mike]

Hello boys and girls

I'm looking for a local (Tokyo or Kawasaki) shop that can reliably and inexpensively do a simple respray job on one of my bikes - a 2006 full carbon Felt FC3.

Specifically I want to get it painted in something like the Bridgestone Anchor "Night Blue" luminescent effect - see http://www.anchor-bikes.com/bikes/design.html under G:NIGHT.

Any clues? I used to respray motorbikes myself, way back when. But these days I'd rather ride...

--Mike--

 

[AlanW]

Warranty!

On most carbon frames you will void the warranty if you respray them at all. The manufacturers are worried about interaction between the paint solvents and the epoxy. I'm sure Polymer_Head will know if this is really possible or just the manufacturers being over cautious.

There was a thread on here a while back:
https://tokyocycle.com/bbs/showthread.php?t=1115
It's got some suggestions if you decide to go ahead.
AW.

 

[Half-Fast Mike]

Re: Carbon Respray

Thanks AlanW. My subsequent research suggests that respraying a carbon frame is definitely possible but expensive as the old finish must be removed by hand. It's getting rather close to the cost of a new frame in the color I want... I may just wait until this one fails (likely with my extra weight) or I get tired of it.

Of the places I've looked, Meito Paint in Nagoya (http://www.meito-paint.co.jp/) seem the most professional. We'll see whether I come into a windfall.

 

[Polymer Head]

I think the warranty issue is to do with the surface treatment of an epoxy surface (low surface energy) and the effects of the interaction of the paint system with the surface treated epoxy (AlanW was partially correct). For example, the use of primers (chemical etching) or abrasion (roughening the surface/removing the glossy surface – substrate, paint and adhesive mechanism dependent) that will aid the adhesion of a paint. Plasma etching, though not at all practical for a CFRP bicycle frame, will also increase adhesion of a polymeric surface. Compatible paint systems are most likely to be epoxy based ones which may or may not require vulcanisation/curing in an oven.

In addition, the manufacturer must qualify the painting process and the paints used. This ensures that the paint has an acceptable finish, is durable, won't peel off or turn another shade after a few hours in the sun. Customers are demanding nowadays aren't they? Protecting brand identity/image comes in here somewhere.

Custom painting a CFRP frame is understandably at the owner's risk especially when you consider product litigation as well. Doable but will it be done well?

For those with insomnia, surfaces for good adhesion are required to have a minimum surface energy and a compatible paint system. For example Teflon (PTFE), 'the non-stick coating' originally introduced on frying pans has a surface energy of approximately 20 mN/m (millinewtons per meter) and after chemical etching, increases to approximately 70 mN/m. Epoxy, depending on the vulcanisation system, is approximately 46 mN/m, compare this to PET (disposable/recyclable drink bottles) which is in the range of 41 to 44 mN/m and 'aluminium' is approximately 500 mN/m, hence very good adhesion.

As an aside, carbon fibres must be treated with a coupling agent, usually silane, to improve adhesion to the epoxy matrix.