Bottom paint naivity (guess this falls under "technique

[MarkWilme]

This should be a quick one, maybe "bottom sanding grunt" can answer :)

In scraping and washing the bottom of Impeckable this fall, some of the bottom paint has come off in large flakes (large being less than the size of a credit card). On examination the flakes are blue on both sides so I assume they are only bottom paint and not any form of barrier coat etc.

So, my dumb question is - other than sanding, fairing and re-application of bottom paint is there anything else I need to do ??? I don't need to apply epoxy resin do I to build up the area thickness - I can just fair and paint - right ????

Told you it was a quick Q :)

[dasein668]

If the rest of the paint is sound, you should be able to just sand and paint. If you are a racer, or interested in squeezing the last possible hundredth of a knot out of your boat, you might want to build the low areas up to minimize any turbulance, but in my opinion that is unecessary for most mere mortal boaters...

The real issue is why did the paint fail? Is there some other issue that might need to be addressed?

[Tim]

Mark,

This is a common issue, and is usually caused by either an overly heavy buildup of paint (in which it cracks and falls off under its own weight), or by improper initial surface preparation.

Or both.

Most likely, this problem will continue to occur each year unless you strip the bottom and begin over. Areas that seem sound now may flake off next year, or the year after. Or, it could be that maybe certain spots were missed when the bottom was prepared when the boat was new, and therefore it only flakes off in those areas.

In any event, don't worry about it. Just flake away any loose stuff, sand the edges, and repaint. Now, if you're concerned about a completely smooth bottom, this is obviously the wrong route--you'd have to strip and start over--but for most cruisers this is sufficient. Just be prepared to see more of the same after next season. Don't use any filler to even up the flaked areas with the surrounding--this will only create high spots in the bottom if you remove the bottom paint, and won't solve the problem.

This problem is as good an argument as any in favor of ablative bottom paints, which will never build up to the extent that they flake off. Say goodbye to flakes and chips and sanding forever. If you ever do decide to strip the bottom, consider ablative. It works well in most seasonal sailing waters; those in the year-round south may feel other paints work more effectively in their area.

[MarkWilme]

Thank you Tim, Nathan

She has ACT on there now which I understand is an abaltive paint, however looking at this flake (in this here zip lock bag) it looks like it may be another type of paint underneath that has failed .....

Hmmm

Last year, yes there were some areas that I had to touch up, but this years scrubbing and sraping was definitely more vigorous so maybe thas part of it - I have to ask how vigorous was the previous owner in the bottom scrubbing arena ?

So no primer, no epoxy, just sand and apply more ACT - thats good ...

M

and Nathan - thanks for your advice the other week on the website design, appreciated :)