plating, anodizing, & finishing Q&As since 1989
Recommendations for a flexible paint system to paint graphite/epoxy bike?
Q. I'm looking for recommendations for a paint system other than PPG products to paint a rare monocoque graphite/epoxy bicycle, which will be auctioned off in early spring, with proceeds going to the Make a Wish and Toys for Tots charities. The paint system needs to have very good adhesion, but more importantly have really good flex/elongation properties to reduce the chance of cracking due to the frame's flex. The PPG water-based automotive system I previously used has cracked twice, which is forcing me to repaint the bike frame for the 3rd time. I was going to try PPG's aerospace system (flexible primer p/n
823X439, CA100 epoxy adhesion promoter, and Top Coat CA88400), but the area sales rep for PPG continues to be non-responsive. I have no other choice but to look for another system due to my schedule. Any recommendations would be welcomed.
I also need a painter in the SF Bay Area to repaint the bike frame. Ideally, I would like someone willing to donate their time for the sake of these charities and the kids, in exchange for some good publicity.
product designer - Benicia, California, USA
January 9, 2009
Ed. note: Sorry, this RFQ is outdated so private contact is no longer available, but public technical replies are still welcome! No public brand/source suggestions please ( huh? why?)
A. I'm skeptical that your problem is the lack of flexibility of the paint but without hands-on inspection I obviously can't be certain. I've painted carbon fiber bicycle frames and forks without using flex additives and had no issues, but the frames have been of conventional configuration. I've also used no flex additives in painting fiberglass and plastic motorcycle bodywork without issue. I would certainly expect any "flexiblized" automotive paint system appropriate for use on e.g. bumper covers to be durable in your application. If you're certain your problem can be solved with more flexible paints then I can say that I've had good results with Valspar's flexible parts primer called PR3. This is commonly used on automobile bumper covers that are highly flexible. They have a low-VOC version called PR4 which I've heard also works well, but I have not used it. Valspar's clears do not require a flex additive even on bumper covers and I've not had any problems. I don't know of any manufacturers that require flex in basecoat paints.Harry Phinney
- Abany, Oregon, USA
January 13, 2009
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