Bottom Paint

[TROUBLE]

My boat was painted with a non-ablative paint last year. (unipoxy) After the bottom was washed upon haulout, i noticed that the paint is in really good condition. there are a few places where the paint flaked but very few. My question is,,, Do I need to repaint the entire bottom or can I just scrape and paint the flaked areas. Its not a matter of time or money,I just dont want to add anymore paint if its not necessary. Its that much more I am going to have to remove when the time comes.

Thanks
Art
TROUBLE

 

[Walter P]

Art,

The reason you got some "flaking" is because the bottom had some areas that were not prepared well enough to ensure good adhesion. Happens to most of us so no big deal. I personally won't re-paint the entire bottom for many reasons including your concern for adding unnecessary volume to what is already there. If you are painting over gel coat or old paint, I would just clean the "spots" well with a proper solvent as per the paint company instructions, then lightly sand. If you are trying to coat over epoxy barrier coat, it's a little more work because the epoxy is pretty hard and you need to work a bit more to scuff it up. In any event be sure to thoroughly remove any wax or other contaminants BEFORE you start sanding otherwise you are just driving the stuff into the sandpaper caused groves in the boat bottom. After all of the above, just touch up the bad areas, and let it dry. If your a bit anal (like me) about the appearance of your bottom (actually your boat's bottom) you can then mix a little of the bottom paint 50/50 with the correct thinner as per manufacturer recommendation. This will give you a watery mix, which must be stirred every few minutes which will color the entire water line to the chine or to the keel if you're ambitious thereby giving a nice brand new looking job without adding much volume.


Walt

 

[Beckytek]

About 6 years ago I sanded the entire bottom to get rid of all the old thick bottom paint. Since then I only give one coat and every year just touch up the bare spots. I don't want the build up again. It works well, with no barnacles or growth. Saves money on paint also. I have ablative paint.

 

[Boatsb]

Ablative or nothing. Too much build up on that hard paint. Clean it off and start fresh.

 

[TROUBLE]

Last night I did some more research on pettit unepoxy and it seems the paint leeches out the biocides and eventually just leaves paint with no anto fouling properties. What I am really trying to find out is if 6 months on the hard and paint from last year means i must repaint. This is a hard antifouling paint not an ablative.

and I do plan on stripping the bottom and going to an ablative but its not in the budget this year.

Thanks again
Art

 

[Walter P]

Good idea to start from scratch with new ablative paint. Remember that key to a successful job is to be sure the surface is perfectly clean. I generally use a product called Brake Kleen as well as a follow up with regular solvent. Another suggestion since you will be undergoing a big job is to paint the first coat of ablative in a contrasting color so that you will only add (repaint) more paint when the contrasting first coat is showing through.

Walt