Bottom prep. Sanding and/or painting?

[Louish]

Hello,
Second season owner of a CD Typhoon in NY. Last year boatyard did complete sanding, light fairing and painting. As I am sending a request for spring bottom prep, is it necessary to request sanding every season or just painting would be enough? What do you suggest?

[Jim Walsh]

It’s really a matter of your particular standards. If you have deep pockets and you have no desire to do it yourself then have the yard sand any loose of flaking paint only and apply antifouling. The result should be a perfectly acceptable bottom. If you prefer to save a few bucks many antifouling paints can easily go two full seasons on one application. That really depends on where your boat is kept as the amount of fouling varies greatly from one region to another. The reason there is a wide selection of antifouling paints marketed is that their effectiveness varies greatly from one area to the next.
If you are willing to provide the labor yourself you have the option of removing the previous seasons accumulation of antifouling and applying a fresh coat every season or, as some do, see how many seasons you can get out of your current antifouling and only reapply when it is no longer effective.
It really boils down to where your boat is kept, what your standards are, and what your tolerance is for boatyard invoices.

[fmueller]

I have had my boat in year round for three winters now so going on 4 years total time in water... what I have learned is that scrubbing your bottom 2-3 times a year is the ticket and a bottom paint job should go for two seasons, sometimes three. The idea that bottom paint alone will keep nature at bay for a season is a stretch. No one racing or cruising full time goes by that assumption - cruisers in warm climates dive on their boats regularly. Luckily we have an affordable diver, who services quite a few boats at RIYC where I keep my boat ... but I also usually do a short haul for one reason or another, usually in the summer or early fall ... and that will always include a quick power wash ...

Last fall I finally decided to do the whole bead blast and Interprotect procedure after 12 years of ownership ... so now I am back to 2 1/2 well applied coats of Micron CSC which is more durable than 66 and works for me because it seems to be long lasting ... I don't expect to have to paint until the fall of '25, but I'll probably have the diver 5-6 times in that time frame and maybe a short haul next spring ... we'll see

When you do paint, do some sanding just to keep it smooth and retard buildup ...

[Louish]

Thank you for the replies and useful advice. I sail in an area with a lot of fouling all over so yearly sanding and painting makes more sens.

[LSD87]

I’ve sanded and painted one year and then sanded where needed and touched up the next. I’ll just repeat the process. Hudson River…