MacGregorSailors.com

That's what I've heard. Since I'm about to have someone apply the bottom paint/antifouling to my Mac, I would like to solicit advice/opinions whether this is true: do you have to put the boat in the water immediately (same day, I guess) into water after applying the antifouling paint?
The paint in question will be Hempel, in case that makes any difference.
European owners might recognize the brand.
Thanks!

I've never heard that, in fact, I would expect quite the opposite in that the paint should be completely dry (maybe 24-48 hrs?) before putting the boat back in the water.

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Completed my annual anti-fouling last week, usually relaunch within 1-3 weeks but according to instructions on tin it could be left for up to 3 months. Although you can put boat into water approx 4hrs after applying paint, I would wait at least 24hrs, especially if you use the harder cruising/speed anti-fouling, to ensure the stuff is well dried out.

I've used about four different manufacture of paint over the years (but not Hempel) and they all say very similar things on the tin, so I would assume Hempel is similar.

Having said all above, I usually get the boat lifted off the trailer to initial launch so that the bits where the beds have been can get painted and the boat then gets put into water within 10-30mins. But I have never seen these areas having any less antifoul left on them at the end of the season, so going in "wet" doesn't appear to be a problem

Cheers
Morris
26X99 hullaballoo Solent UK

I would read the manufacturer's recommendations.

Many years ago we used this copper based paint that said launch within 48 hours, even while still wet. I don't think modern paints work this way though.

the antifouling effects of the paint (many types) dissipate with contact to the air and should be put on verry clost to launch time. Last year i was advised by a dealer not to use antifouling if i would be taking it out periodically through the season. we chose a different kind.

The hard racing anti foul I have found better for boats that spend time on a trailer. It has a gloss type finish.
The dull one I believe does last better in the water, and not so well on a trailer boat.
The instructions tell you when you can put the boat in the water. It is listed in hours drying time.
Cheers
Phillip

I did ask 'INTERLUX' the manufacturer of the ablative paint I have been using these past 6 years, that same question. And the answer was ""No longer than 72 hours"". However, I am sure that is not absolute and would change with varying temperatures and humidity.

Cheers,

Ron

The stuff we used in the 60's on crayfishing boats was applied and the boat launched within a couple of hours...the criteria being to NOT allow the antifouling to dry out enough to POSSIBLY DEVELOP CRACKS...if it did crack, that is where growth can get a ' foothold'. Pugs,

The reason for the uncertainty and confusion is that there are different types of antifouling paints. Ablative paints can be removed from or kept out of the water and left to dry because the paint wears off (ablates) like a bar of soap in the shower. This contantly exposes new paint/new copper to the surface. Hard antifouling paints on the other hand must be launched quickly after painting and must remain wet. If left to dry, the copper can no longer leach to the surface and the paint becomes ineffective.

Trailered boats should therefore use ablative if they need an antifouling. I use ablative as well because you can remove the boat for the winter and the paint will last multiple seasons.

In theory the tradeoff is that ablatives slow you down a bit. I've never worried about that though and I always use ablative paints. Just seems easier to deal with in a trailer sailor situation - which both my boats are.

Back in the 60's I used copper bronze paint. You were suppose to paint on a dry day with temps over 60 and under 80. the boat was to be painted in the morning and launched with in 6 hours or so (according to the can)

Talk about nasty stuff. Especially when you sanded it in the spring. That copper bronze would kill you. Even with the best masks available I would have a copper taste in my mouth for a week or so.

I have a partial can of a hard anti F paint. It doesn't say anything about being put in the water within so many hours.

So heres my question. If you trailer some times, and the boat is out of the water for say 2 days will the new paint crack as it dries?