Hard antifouling paint is supposed to be left in the water all season and painted the beginning of the next season. If for some reason boat is being hauled out and launched at a later date there are steps that should be followed (see below). Not sure how much effectiveness of antifouling will be reduced if process not followed.
Boats that have been launched but are in the water for less than 24 hours – Lightly pressure wash to remove surface contamination (salt and dirt etc.). Follow label instructions for maximum launch time from date of painting.
Boats that have been in the water for more than 24 hours but less than 30 days – Pressure wash immediately after hauling. No additional work is needed if the boat is relaunched with 72 hours. IF the boat will be out of the water for more than 72 hours will need to be sanded with 220-grit sandpaper immediately prior to relaunching.
Boats that have been in the water for more than 30 days – Pressure wash when hauled, sand with 80 or 100-grit sandpaper and recoat. Recoating is necessary even if the boat will be out of the water for less than 72 hours.
Like I said above I think if the boat is out of the water for a period of time antifouling starts to oxidize preventing release of chemical to prevent fouling growth. I must admit I find a lot of the stuff very far hard to believe and have a hard time believing all this sub particle information . But who am I to say I don't have a degree in Chemical Engineering. To tell you the truth I was so surprised there were so many types of antifouling paint.
I ended up getting all this information from the Interlux website so I don't doubt what they are saying. But really not sure how much difference it would make if you just hauled the boat out and put it back in without doing anything. I was originally looking at VC-17 as it is very durable but as far as I can tell it only comes in white. I want to paint the hull with Brightside Polyurethane sapphire blue so the white undercoat will not match. I have also read that Brightside should only be used above the waterline but can be used below the waterline if not left in water for long periods of time.
Our boat came with VC-17 so we were not about to change systems. We generally keep Shortwave in the water all season and the paint works nicely. Just before the Rendezvous there is usually a small amount of scum that wipes off easily. We re-paint very other year. We've got the copper colour which turns black when in the water. We also did the rudder with VC-17 because we leave it in the water. The only problem is because of the black colour it's hard to see weeds on the rudder. White would have been better. If the boat didn't stay in the water as much I'd probably just stick with a waxed hull and clean it once in a while. The other thing that helps is we're tied up at a dock where the depth rapidly drops off to about 70 feet and there is a slight current. Being moored in shallow (warmer) still water would cause stuff to grow faster on your hull.
Loc: Mazinaw Lake
The quality and accuracy of the information being posted in the project threads is phenomenal. I'm thoroughly enjoying the dialogue, the reports, the photo essays.
That's an interesting bit of trivia about bottom paint. I didn't know that. Does that imply that the Lake Ontario boats with the fresh paint jobs weeks before the spring launch are not going to enjoy the benefits of their work?
Boats that have been painted and are past the maximum time before launch on the label but no more than 12 months past their launch date – Scuff sand with 220-grit sandpaper or a maroon Scotch-Brite pad prior to launch.
Boats painted more than 12 months prior to being launched – sand with 80 - 100 grit sandpaper and recoat prior to launch
Most season-to-season antifouling paint should be launched within 60 days of being painted. The boat should not be removed once launched as antifouling will start to oxidize once out of the water.
Absolutely no time to work on my Sandpiper, so I said to myself you can at least turn the keel handle . For my Sandpiper it takes approximately 87.5 turns to put the keel down fully. Each turn of the handle lowers the keel about 1/4"
Now I just need to get the sander in my hand then the paint brush.......How it is looking now this maybe a project for next year, but you never know. Reading all these restoration post from Happy Camper and Seafari is giving me a complex
The spec sheet for the Sandpiper shows 10" draught at KEEL UP and 2'11" (35") at KEEL DOWN. That's a difference of 25" or 100 turns of the 4 TPI keel screw. However, the majority of us get less than 100 turns.
Sandpipers have really short stubby keels. It's got to be hurting our performance.
Keel area is typically a percentage of the sail area. This may explain why Sandpipers are under-canvassed and need to reef early.