Getting ready to add new/first antifouling coat

Stiche · #1 (**permalink**) 10-21-2008

Hi all. I've has a '69 Cal 25 for about 2 years now that I've been meaning to polish up and re-christen, unfortunately Uncle-Sam kept getting in the way by sending me to the sandbox each year!

Now I'm back and I figure the first step, should be a new bottom coat. The Cal does not appear to have an antifouling coat on it (freeboard trim and bottom coat are the same color/tone) and despite its age, the existing coat is in decent condition...no flaking, just some chalky run lines from the oxidized gel coat (that's next!)

The boat will be moored in Seattle, Washington, in fresh water Lake Washington/Lake Union all year and will be used for day sails in Lake Washington and 2-4 day sails in Puget Sound (saltwater). The most obvious nuisance is the various milfoils that have taken over the bay.

From everything I've read, I'm thinking all I will need for prep is a light sanding, 80 grit wet/dry sandpaper, removal of the dust with a cleaner and clear weather. I've had two coats of Interlux Bottomkote ACT recommended, which I'll apply with either a pump-roller or airless sprayer.

Before I good in the wrong direction, I'd appreciate a sanity check on this. This is my first time fixing up a boat some I'm in uncharted waters!

The boat will be dropped back into the water January, as my wet moorage sub-let is vacating and I don't want to double-moor the boat, so I'm racing the temperature clock. Highs drop to only 52 by the end of next week so I'm hoping to apply the two coats on Sun-Mon (26-27 Oct) so that the paint will adhere well.

thx!

-Mike

sailingdog · #2 (**permalink**) 10-21-2008

Given that the boat has no bottom paint on it... why don't you barrier coat the bottom before putting any paint on it. It would probably be a good idea, and help prevent any future osmosis problems, as well as giving you a really good "primer" surface for the anti-fouling paint. I'd highly recommend putting four or five coats of Interprotect 2000E on the bottom and then putting the anti-fouling on afterwards.

BTW, before you sand a fiberglass bottom, it is generally a really good idea to wash it well, so that the sanding doesn't drive any surface contaminants into the fiberglass/gelcoat.

Washing the surface with a strong detergent like Trisodium Phosphate is probably an easy way to do it. Then sand it, and wipe it down with some Fiberglass Prep Wash 202.

If you want suggestions on how to apply the IP2KE let me know.

T34C · #3 (**permalink**) 10-21-2008

From the Interlux site:

We are happy to answer any product questions you may have and to give technical support on the application of our products. The Interlux technical service helpline 800-468-7589 is open Monday through Friday to assist you.

Or contact us via email at Interluxtechnicalservice@internationalpaint.com

I have found their customer/tech support to be excellent. I would recommend talking to them. They should also be able to advise you reguarding the application with the dropping temps.

Fstbttms · #4 (**permalink**) 10-22-2008

Quote:

Originally Posted by Stiche

I've had two coats of Interlux Bottomkote ACT recommended, which I'll apply with either a pump-roller or airless sprayer.

Before I good in the wrong direction, I'd appreciate a sanity check on this. This is my first time fixing up a boat some I'm in uncharted waters!

Bottomkote ACT is an ablative paint. In-water cleaning of ablatives is banned in Washington. FYI.