Waterproof top coat for surfboard??

[John C.]

We want clear, waterPROOF as possible, and with UV absorbers. The board is made with fiber reinforced epoxy resin. The epoxy surfboard resins soak moisture. Paint companies don't give water absorption data. Our best choices so far are a DuPont higher quality 2 part polyurethane automotive clear coat named Chroma, or marine LPU water based or solvent based. I've also come across a high quality teflon filled 2 part polyurethane DuPont Imron, and a ceramic filled very thin paint called Cerakote http://www.vikingperformancecoatings.com I'm having a touph time finding something waterPROOF as possible, any help? please John C. San Diego California USA

[Gordon]

Hi John C:

to the Surface Engineering Forum.

All organic paint coatings are capable of transmitting moisture at the molecular level to some extent, no matter what your paint supplier claims. Densely cross linked coatings like epoxies and polyurethanes generally exhibit the lowest moisture permeabilities. I think you will also need to consider what lies beneath your top coat to combat problems associated with blistering, osmosis, wicking and hydrolysis.

These links may be worth looking at:

Guide to osmosis and its treatment

osmosis' and blistering of GRP yacht hulls