by dbeck on Mon Nov 27, 2023 2:01 pm
Our supply shop recommends microspheres (white stuff, made of glass) for use below the waterline.
They also sell microballoons (brown stuff, made of phenolic substance); they do not recommend it below the waterline unless sealed with an additional coat(s) of epoxy.
However, when asking google it seems that the terms microballoons and microspheres are sometimes used as synonyms for the same stuff.
Very confusing.
What we did: We treated the rough spots with a normal fairing (white microspheres) mixture, then sanded. Then, our final 'epoxy coat' has been epoxy only slightly thickened with some white microspheres. We applied it with a roller over the entire lower hull. This was sanded with 120 grid paper. Then we coated the entire lower hull with epoxy primer. This was sanded with 120, then 240 grid paper and finally had satin-like look. I believe the epoxy primer helped in getting a smooth surface for painting.
Cheers,
Dietrich