high gloss coatings for carbon fiber?

[ambertch]

Hi all,

I'm just wondering what material is usually used for a high gloss piece of carbon fiber say for presentation purposes. varnish? sanded epoxy?

Thanks,
Ambert

 

[Compositepro]

Almost any clear polymer coating can work. One of the best and most common is solvent based urethane. The solvent lowers the viscosity and surface tension to improve leveling of the coating, which is essential for gloss. Sanded carbon fiber surfaces have significant variations in surface energy between the epoxy and carbon. Carbon fiber are all surface treared to improve adhesion to polymers. Surfaces exposed by sanding have not been surface treated.

Most urethanes are moisture curing; they crosslink by reaction with atmospheric moisture. They have excellent environmental durability and are water clear.

Glossy surfaces can be made directly during the molding process, also. However, this requires careful mold preparation and a well designed molding process to prevent surface pitting. In addition the surface resin will then be epoxy if you are using epoxy prepreg. Epoxy typically yellows on exposure to sunlight

 

[ambertch]

can you recommend some brands?

Thanks for the reply!

 

[Compositepro]

I've had very good results with #7615T12 from

http://www.mcmaster.com/.

At room temp. it takes about a day to completely dry and another two to get good hardness. Oven bake speeds things up.