Bottom painting (now) in fall- good or bad

laureniac1

So it was 80 degrees today 10/18/16 in Cleveland and my boat has been on trailer since 9/27/16. I know not a fisherman. I decided to touch up my bottom paint. I use Pettit hydrocoat ablative. My boat neighbors said it is not good to bottom paint before winter because the boat weeps water through winter. He said if the water freezes and can't get out I could crack gel coat. Please tell me I will be ok!!

raybo3

I have painted in the fall before with no problems......... You will be fine....

Liberty44140

You will be just fine. Hydrocoat is a great bottom paint. It is water based so any water that gets on it is no big deal. Bottom paints are not sealers, they do not seal out water like an epoxy barrier coat will. Hydrocoat lasts 5 years so you can sit pretty while your neighbors paint every spring. Trust me though that 5 seasons on lake erie is it, I've gone to 6 and it was no longer effective in year 6. You are fine. 

laureniac1

Thanks for feedback. Some areas are like brand new with Hydrocoat and others I have to touch up yearly. Can't figure it out. The same spots flake every year

Dream_Inn

I agree with others, no issues painting right now.  As far as same spots flaking, are they areas that rub on the trailer?  It could just be that they got down past the barrier and now paint isn't sticking.

Michael T

@laureniac1. Because Pettit Hydrocoat is a water based ablative, it is in essence, a semi permeable membrane that has one way vapor barrier characteristics. If properly applied it will resist water penetration onto the barrier coat surface and allow vapors to exit outward. Remember, of course, it is not the final outer coat (ablative or sanding required) that saves your boat - it is the first coats that go against the gel coat known as barrier coats. You will be fine with what you want to do.

You can re-coat Pettit Hydrocoat within 3 hours if you need to do two touch-ups to the same area and it has an indefinite launch window, meaning it could probably be launched within 4-5 hours of painting but - better yet - can be painted-on in the Fall and left over the Winter without loosing its antifouling properties, unlike some paints that must be launched within hours.

The guys on this forum have great advice based on long term boating knowledge. Many manufacturers have chemical technicians who will discuss their products with you. Pettit is one of those. A year or so ago I posted a bunch of phone numbers on the forum of the techs I was speaking with at Pettit and Interlux - both, imo - great companies.

laureniac1

Wow thanks Michael T that makes me feel better

Michael T

@laureniac1 I missed your comment about spot flaking. Here's my 2 cents:  When preparing the hull, that is the gel coat surface, by de-waxing, chemical wipe and sanding - before applying the barrier coats it is very easy - even for a dedicated and experienced gel coat/ bottom coat tech to not get off all of the mold wax from the factory or bottom wax from an owner. 

In spots where some contaminants are left on it can lead to spot flaking.

If you think this area(s) are either too unsightly or worse might destabilize surrounding bottom coat (not really likely) you can sand the area with 80 grit sand paper to remove existing ablative coat (Hydrocoat) then wash with mild soap, rinse with water, let dry and re coat with Hydrocoat.

You do not want to sand hard enough to remove the barrier coats under the Hydrocoat.

This is an easy job to do "delicately" but you do not have to do it at all, unless you don't like the appearance or think the surrounding area(s) are being compromised.