Anti Fouling Paint

Aug 11, 2020
6
Hunter 170 Lighthouse Cove On
Good Day, I’d like to paint the bottom of my plastic hunter 170 with some already purchased special anti fouling paint and I don’t know how to prep the bottom area where I’m planning to paint at and below the water line. The paint was very expensive so I don’t want to mess it up. The slip where I keep my boat (new to sailing) on L St. Clair left me with some challenge algae. Thank you!
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
Instructions are on the can. Follow them. If it is bare fiberglass/plastic you may need to add a layer of primer. But there will be instructions for never before painted surfaces. You can also go to the paint maker's website for instructions.... and.... many companies will have instructional videos on YouTube.
 

RoyS

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Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Be careful. Some paint companies would like you to sand off most of the previous coating and then replace it with two coats of new paint every year. This is good for paint sales but not so good for you, your boat, or the environment. Around here, the marinas haul the boat in the Fall and pressure wash the bottom. Most boat owners apply a single coat ablative paint the following Spring just before launching. I use a multi-season water based ablative and only touch up chips in the Spring and I only apply one layer re-coat about every four years. I never sand. This system will never require stripping the bottom because of paint build up. This works for me.
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
I would say just be sure that you use a primer suitable for plastic, will be compatible with the paint you have chosen, and is also suitable for marine environments. I just painted a fiberglass boat with VC 17M, and the manufacturer recommended starting with 5 coats of Interprotect epoxy paint to prevent blistering of the fiberglass. With plastic, I would think blistering would not be an issue. Also, the Interprotect sets up fairly rough, so I had to do some significant sanding in order to get it smooth enough.

I recently painted the bottom of my plastic H170 and used Krylon spray paint. It worked pretty well, but I had to sand in places to smooth out the overspray. I don't keep my 170 in the water, so I did not apply any anti-fouling paint.

Prep for you will include pressure washing then sanding to get off any stubborn residue. You do not want to apply anything until you have it all nice and clean.