I’m looking to tidy up a Kinesis Maxlight pro2 frame, and my most ambitious thought so far is to have it powdercoated. It has carbon rear stays though…

Does this render it a bit of a dodgy plan, or can anyone recommend a process to get it right? I’ve painted a couple of old road frames before, but that was the simple process of hammerite on a steel frame!

Depends whether carbon fibre likes being at 180 degrees, probably not, plus the powder coat won’t stick to the carbon (I’m guessing).

true- The plan was to mask the carbon and powedercoat the rest. They get paint onto them somehow when they are made, so it must be doable somehow..!? ❓

I am pretty sure that you need an electrical conductor to powder-coat, and something that like higher temperatures. Carbon fiber is the opposite of these two, and is usually painted – I’d approach a painter. Less durable and more expensive, but looks nice 🙂

Not a chance. Whatever resins used would just melt away surely. I’d be looking at a two-pack finish, with a stabiliser over the carbon. It would need more prep but would be fine. A car sprayer could probably do it for you.

They get paint onto them somehow when they are made, so it must be doable somehow

that’s ‘cos they paint them not powdercoat them.

just talk to someone about getting it sprayed and laquered. They’ll need to be careful with how they strip so they don’t damage carbon – I’d be goign to specialist bike refurbishers rather than a local spray anything workshop.

Argos cycles will do carbon frames – pricey mind…

http://www.argoscycles.com/www/renovation-pricelist.htm

Carbon conducts electricity, so that shouldn’t stop you powder coating. Resins cure (I seem to remember) at about 120 deg C so that may limit processes. Also chemical compatibility of the paint and resin.

You won’t be able to powdercoat it. The temperatures required to powdercoat will be damaging* to the carbon fibre. They heat up the powder to get it to melt and react. If you are going to get it done you’ll have to do it with paint.

*They’ll be thermoset so they won’t melt.

So it looks like paint is the way; Anyone know the best way to approach spraying an aluminium frame?

Argos cycles looks idea, but this is not the most top notch or collectable frame, so i’m inclined to a cheaper solution. Depending on cost, could i get this done in a motorbike shop? Any goos DIY approaches?

I have done extensive R&D into powder coating a wide variety of composite materials. Generally speaking, carbon fiber materials can be powder coated as long as the resin system (usually a thermoset epoxy) has a Tg greater than 250*f (with the exception of specialty ultra-low curing powders that will cure at lower temps.) The problem with powder coating carbon fiber without the aid of a conductive base coating is ANY surface defect (minor scratch, area of irregular distribution of fiber to resin, knit line etc.) will be amplified post cure. Novoc Solutions Inc. (http://novocsolutions.com/) has the best pre-treatment system to aid in powder coating of composite materials and will eliminate the telegraphing of minor substrate defects through the finished film.

Don’t risk it.

1. the carbon fibre composite is not conductive so the powder coat won’t stick unless you apply a conductive coating first (as mentioned above).

Technically you could generate static on the carbon fibre surface which could be used but as it is bonded to a metal frame it would be earthed and you would also need to maintain the charge so again its a bit of a no-go without a coating.

2. Even if you mask the composite and just coat the aluminium, the thermal expansions of the aluminium and composite parts are different so when you melt the powder coat you could damage the joints between the different materials.

3. Without knowing what the resin system used is and what cure cycle was used and the Tg you have no idea if your powder coat heating temp will be too high and cause damage.

ie the quick answer is paint it.

The easy way to do so is get the composite bits masked off and protected and strip the aluminium and paint as normal for aluminium.

Or if you want the composite painted just use a primer an paint that is okay to use on composite. Not hard to find as fibreglass body parts have been around for a long time. I’d probably use 2 different primers though for the different materials – an etch primer for the aluminium and one suited for composite on the composite. Not sure if etch primers are recommended around bonded joints though.