Differences between bottom paints

[Solarisphere]

Wow, I've been lurking for a while but I think this is my first post.

I'm restoring my dad's old 26' Thunderbird that has been sitting on blocks for the last 20 years, and it needs bottom paint (in addition to many other things). I've been reading up on it for a while now but my understanding of the different brands and their various products is still a little hazy.


So here's what I've got so far:

Pettit makes 3 multi-season ablatives: Horizons, Ultima SR-40, and Ultima SR-60. The Ultima 40 and 60 are identical except for the copper content. Both contain Irgarol (Pettits anti-slime additive) while Horizons doesn't. Ultima SR-40 has 40% copper, SR-60 has 60%, and Horizons has 47.5%.

Interlux makes Bottomkote XXX, MicronCSC, Micron Extra, and Micron 66. Micron 66 is out of the question as it's apparently hard to apply yourself. Are MicronCSC and Micron Extra the same paint, but with anti-slime additives in the Extra? And where does the bottomkote come in? Is it just another ablative? Does it work as well as the Micron?

It seems like none of the marine stores or even the local distributor sell Micron Extra or Ultima SR-40/60. Is that because we don't get slime in this area? The boat will be moored in Victoria, just northwest of Puget Sound.

I've also read that the Micron doesn't begin to ablate until you reach 6-7 knots while the Pettit paints start at 2-3 knots. Does this mean the Pettit paints are better for sailboats that won't regularly be reaching 6 knots? Or does the Micron work well if you sail often enough?


Any help with this would be greatly appreciated. I'm feeling a bit overwhelmed by all this.

[DrB]

Micron 66 is out of the question as it's apparently hard to apply yourself.

- This is not correct. This stuff applies like any other bottom paint. I have put it on my boat for several season. I also have found it to be the best out there fore slime, growth, and general bottom cleanliness, albeit, I haven't tried many paints.

I've also read that the Micron doesn't begin to ablate until you reach 6-7 knots while the Pettit paints start at 2-3 knots. Does this mean the Pettit paints are better for sailboats that won't regularly be reaching 6 knots? Or does the Micron work well if you sail often enough?

Some micron paints require 6-7 knots to ablate, but not Micron 66. Also, if you sail your boat enough, the Ablate Speed should be a non factor.

I tried a Petit Single Season paint last year and it was poor compared to Micron 66. I painted half of the hull with the Micron 66 and the other half with the Petit. The boat was hauled for a day in September (after being launched in early May) and the difference in growth on it was night and day. The Micron had little growth, while the Petit side had growth and slime.

For any bottom paint, if it doesn't have anti-slime, you can always add it. Some companies make anti-slime additives.

DrB

[JimsCAL]

I think you can put most bottom paints used in salt water into one of three categories: hard epoxy, single season ablative, multi-season ablative. I've used all three and find little difference in how they work, at least based on using quality paints, hauling for the winter, and applying a new coat each spring. I have been using Pettit Horizon the last several years and find it works well here on Long Island Sound and that buildup is not a major concern like it was with hard epoxy (Trinidad). I like that the remaining paint with a multiseason ablative will still work after the winter haulout. Worth the premium over a single season ablative.

[RobGallagher]

I just want to add...

If you plan to haul your boat every year, multi season might be a waste of your $$.

After a decade of experimentation; If I put on multi season it is because I plan to store my boat in the water for the winter and have had no problems as long as I get the bottom cleaned in the fall. Might need a scrub by spring time, but not so much it can't wait till the water warms up.

Using multi season for one season has resulted in less work in the spring as the boat comes out looking like it was just painted (after a power wash). When launching in the spring I used to put on one coat, but, the build up was too much and I ended up doing a lot of sanding after 3-4 years.

I can get three seasons (not three years) out of two gallons of Micron Extra as long as I get the bottom cleaned 1-2 times per season. (30 ft, fin keel). i.e.; Paint, spring launch, season 1, wet winter, season 2, wet winter, season 3, fall dry storage.
Paint = two full coats, third coat on rudder/water line/leading edge of keel/bow till I run out of paint.

Best advise I can give is to change colors every time you paint so you can tell what's going on. Some seasons will be worse than others for growth so your results may vary year to year. Also, if you spend money on better paint and bottom cleaning you will do less work when you have paint.

YMMV

[Fstbttms]

Originally Posted by Solarisphere

Micron 66 is out of the question as it's apparently hard to apply yourself.

Originally Posted by DrB

- This is not correct. This stuff applies like any other bottom paint.

Both the Interlux web site and product spec sheet indicate that Micron 66 is formulated for professional application.

Originally Posted by DrB

-Also, if you sail your boat enough, the Ablate Speed should be a non factor.

Perhaps. But in regions of moderate-to-high fouling, Micron 66 (or any paint) will foul to the point of requiring cleaning, regardless of frequency of use.

[DrB]

Both the Interlux web site and product spec sheet indicate that Micron 66 is formulated for professional application.

I haven't look at Interlux's Website for Micron 66, but I have applied it 3X on my boat with simple roller for large area and a brush for the nook and cranny areas. I have also purchased at many do-it-yourself boat supply stores. Why would they sell it to the general public if you need to be "professional" to apply it? I have no idea why Interlux states that it is a "professional" paint.

Perhaps. But in regions of moderate-to-high fouling, Micron 66 (or any paint) will foul to the point of requiring cleaning, regardless of frequency of use.

Agreee, but the OP said he was north of Puget Sound, so cold water which typically results in low fouling. Nevertheless, more frequent use of one's boat will result in a "cleaner" bottom compared to a non-frequently used one, and therefore less frequent haul or in the water clean.

[chef2sail]

I am using the petit Ultima 60 this year for the first time with good results. I also had used the Micron Extra for the last 8. I have noticed the petit is a bit better in our area. I have a diver go down 2 times a year and the boat will stay in the water for the winter.

Maintainence of the paint is just like anything else on the boat which requires a cycle of maintainence.

Dave

[Fstbttms]

Originally Posted by chef2sail

Maintainence of the paint is just like anything else on the boat which requires a cycle of maintainence.

Absolutely true. And furthermore, relatively frequent, gentle cleanings will prolong the life of your anti fouling paint as opposed to less frequent, more abrasive cleanings, which have the opposite effect.