How do I know if I need to repaint the bottom?

[marcusn]

When I bought my 1975 fresh water boat last year, it appeared the bottom had been painted 2 or 3 years ago. It's been kept in Lake Michigan for 3 months each of the last 2 summers. Should I repaint this Spring? I'm not sure, by looking at the hull, if it's really needed.

Thanks all

[marcusn]

I'm thinking I don't need to repaint. Can I know by look or feel of the hull?

[pschoonveld]

If it isn't flaking off or otherwise falling apart, you probably don't need to. But, depending on where you're at, expect to have some critters robbing some of your speed by the middle of the summer.

Paint's cheap, in the grand scheme of things. Depending on what you use, it takes an hour and keeps the zebra mussels off. Though, on Lake Michigan growth isn't a huge deal.

An hour of work and $100 worth of paint is usually worth the effort. The hassle is if you don't know what the previous owner put on. If you don't know, you're best to sand it back.

Check out VC17 by Interlux. Foam rollers and the stuff lays ridiculously flat. I just repainted mine and the other guys in the new yard couldn't believe how smooth it is.

[sailingfool]

You should try to figure out what type of paint you have. If it is a hard paint or a one-season ablative (which I've never seen...), then in general you should put a fresh coat on every year, and every 6-8 years you need to remove them all and start from a bare bottom.

If it's an all season ablative, you don't want to produce a buildup of paint, so you only want to paint when the paint is getting thin, usually demonstrated by some visibility of what's under the paint: glass, barrier coat or a different color base coat.

Can you find out fromthe PO what paint was used? If not, you might see if the yard can id the paint.

[saurav16]

Anyone know if Interlux BottomKote can go more than one season? Boat was only in the water for 1.5 months last year.

[jimq26]

I have used it for the past 10 years, and find that it stands up just fine here on Lake Ontario. The boat is in the water May to October.
We buy a 1 litre can each year of the XXX, and use it to touch up where needed (usually a few spots along the water line, and the odd spot here and there).
If you get a really good pressure wash done when hauled in the Fall, you will have good longevity in your bottom paint.

[JimsCAL]

Bottomcote is a hard epoxy. Bottomcote ACT is a single season ablative. Both need to be repainted if boat has been hauled for the winter.