Hi All,
I am in the process of finishing my second Pygmy Boats Coho. I have purchased a six ounce can of West Systems graphite powder (#423). What I want to do is to use the powder in some epoxy and apply it only below the waterline, to increase abrasion resistance.

I normally mix either 1.5, 3 or 4.5 ounces of epoxy at a time. I guess I will need less than 6 ounces of epoxy to complete this task. The instructions say to use one tablespoon of graphite per 5 ounces of epoxy, so using 1 tablespoon in a 4.5 ounce epoxy mix is just about ideal, according to the instructions.

My questions concern the MAXIMUM amount of graphite that can be used. Does the ratio recommended on the can give a nice opaque grey color, and at this concentration is it at its optimum hardness? How much does the epoxy viscosity increase with the addition of the graphite? If I, say, double the amount of graphite concentration will the color be more opaque, and the coating be more abrasion resistant? Will also the viscosity not increase very much? I do want the epoxy to flow on nicely since it will probably be hard to sand.

Also I am thinking about putting the proverbial dark stripe along the shear line. I really don't need it to hide anything as the shear seam is pretty tight and clean looking. However, instead of considering paint which would not be very abrasion resistant, I was thinking of using graphite power in epoxy as a paint for the shear stripe. This would at least resist stratches better. Any thoughts on this?

Regards,
Steve Pituch, Corpus Christi