Bottom Paint

Need to bottom paint my KK-39. The choices are hard paint or self polishing paint, specifically Pettit Trinidad PRO or Cukote respectively. I need to decide which is the best option and why? I would appreciate any experience-based advice.

Thank you

For a slower boat like your KK-39 I think that ablative paints are better. They won't build up a thick layer over time, can be hauled and relaunched with no affect on their performance and I think they work better than hard paints. Also consider the water based Trinidad Hydrocoat SR- better on the environment.


For a fast planing boat it is better to use hard paints as an ablative will quickly be worn off


David

I had Southerly bottom painted in Freeport Bahamas. Charlton Knowels marina. 7 year paint (different regulations in the Bahamas). Great guy and I am very pleased. So are my divers.

If you haul ever season I’d go with an ablative as David mentioned. If the boat stays in the water year around, I’d go with a hard.

We use a hard now and can go 2.5-3 years between painting. The bottom gets cleaned on a regular basis. When we had an ablative, in warm water, with regularly cleaning, we only get about 18 months before the paint is gone.

If you have an ablative and then want to switch to a hard, most paint manufacturers want all the ablative removed before you can apply a hard paint so that’s a consideration.

Thanks folks.


The bottom has had ablative paint on at least for the past four years. I just bought this boat recently with a few small blisters (otherwise in very good condition) which were discovered during the survey. To take care of the blisters, we will have all the old paint stripped to do the necessary repairs. Since we will be starting with a clean bottom and, would like to do some long cruising next year, that is why the alternative bottom paint is being considered.

If you are going down to bare fiberglass then you should put on an epoxy barrier coat before the bottom paint.

Comodave said:

If you are going down to bare fiberglass then you should put on an epoxy barrier coat before the bottom paint.

Click to expand...

Yup, do it now so you don’t have to strip the bottom again. Interprotect 2000 by Interlux would be my choice. Their Microplate technology does work.

I’d use an ablative / self polishing on your boat.

No mater what paint you choose be sure it has an anti-slime compound in it. Pettit paints with anti-slime are labeled SR. Interlux adds a chemical they call Biolux on the label. I don’t know what Sea Hawk calls theirs.

It is CUKOTE that i used on my Manatee,,,,,I also add more copper powder and very hot pepper powder in the paint. It lasted over 3 years so I recently repeated the the same.

gahmadi said:

...The bottom has had ablative paint on at least for the past four years. I just bought this boat recently with a few small blisters (otherwise in very good condition) which were discovered during the survey. To take care of the blisters, we will have all the old paint stripped to do the necessary repairs...

Click to expand...

No need to strip the whole hull to fix "a few small blisters". Unless there are other reasons to strip, like a/f build up or adhesion problems, you just repair the blisters,prime the repair,and reapply antifoul. For compatibility, it helps to know what is on there already.

silentfaith said:

It is CUKOTE that i used on my Manatee,,,,,I also add more copper powder and very hot pepper powder in the paint. It lasted over 3 years so I recently repeated the the same.

Click to expand...

The hot pepper does nothing and adding copper powder in the U.S is illegal.

I am currently having Magic painted with Cukote. What tipped me in that direction is the 1-year warranty against hard growth. The product must be applied by an approved yard. If you have hard growth and take it to an approved yard my understanding is they will cover everything to redo the painting. The details are on the Seahawk website.

Red pepper, copper powder, terramycin all greatly improve bottom paint. The paint manufactures don’t want you to know that because they would sell less paint!

Oh yeah, the Earth is flat and the Moon landing was faked.

HopCar said:

Red pepper, copper powder, terramycin all greatly improve bottom paint. The paint manufactures don’t want you to know that because they would sell less paint!

Oh yeah, the Earth is flat and the Moon landing was faked.

Click to expand...

OMG HopCar, Terramycin? You are as old as me!

hmason said:

OMG HopCar, Terramycin? You are as old as me!

Click to expand...

Oh yeah, I’m that old. I remember that a marine company actually sold little veils of terramycin to add to bottom paint.

Don’t forget to put magnets in your fuel filter to kill the bacteria and improve your mileage.

My boat is on the hard in NJ, how long between stripping bottom paint and barrier coating? Will a few months of winter allow the hull to dry?
No blisters just too many coats of paint.
Greg

I started with the ablative Micron and was very disappointed. It works great on my charter boat that cruises at 15 knots. At 7 knots on the trawler, it doesn't ablade well. Only time it sheds is when the diver scrubs it. Sanded it off and went with Petit Trinadad SR (yard version). The yard version is the same paint as Trinidad SR except it's only available to boatyards at about $100 less per gallon. Petit's logic is that there's no marketing cost so they sell it cheaper and the boatyard can be more competitive on bottom jobs while still getting a good markup on the paint. Hope to get 3 to 4 years out of it.

Ted

Beekeepergreg said:

My boat is on the hard in NJ, how long between stripping bottom paint and barrier coating? Will a few months of winter allow the hull to dry?
No blisters just too many coats of paint.
Greg

Click to expand...

It depends on a lot of things, how wet is the hull, how much humidity is in the air and what temperature is around the boat. The hull will dry out quicker if the boat is in a dry warm area. But if you are going to strip it you should barrier coat it if it isn’t already.

Here is a 2014 article on a number of AF products in Australia. Interesting takeaways are that the more expensive, or higher copper content paints, are not necessarily better performing.

http://www.pacificpaintandfibreglas...9/Cruising-Helmsman-Article-November-2014.pdf

Some of the AF tested are no longer available. I had been using CuKote while the boat was in the PNW. On bringing it to Australia I started using Micron Extra. Performance was adequate at best. In March this year I changed to Jotun Seavictor 50. It seems very good, so far!

Greg should probably start his own thread about his individual hull query, but if it has no blisters and simply has an excessive antifouling paint buildup needing removal, why would it be wet and need to dry out? Subject to the requirements for recoating it should be good to work on after the water used to wash it down evaporates.

Delfin was just sandblasted to remove all barrier coat and layers and layers of bottom paint. After a whole lot of discussion and research, I went with Interlux epoxy coat and their Interspeed bottom paint. This is a semi-ablative paint, so it will slough, but not quite as quickly. It is the same system the U.S. Navy uses on many of their boats, and Interlux's technical rep was helpful in inspecting the work as it progressed in the yard. I asked him about modifications of the paint (more copper, etc.), and he indicated that if there was an additive that would extend the utility of the paint, they'd be all over it, since the really big purchasers of bottom paint would flock to their doors. There isn't such a fix, so they don't.

The rep thought I should get a solid three years out of this system.

Incidentally, we used silver, then bronze color on the epoxy, then overcoated with first red, then black bottom paint. That way whatever color shows through tells us what stage wear is at.

Beekeepergreg said:

My boat is on the hard in NJ, how long between stripping bottom paint and barrier coating? Will a few months of winter allow the hull to dry?
No blisters just too many coats of paint.
Greg

Click to expand...

In the NE, unlikely, but a yard with a moisture meter can tell you. Once dry, the barrier coat can start to go on anytime, but the sequence after that is critical. The second coat of epoxy goes on within 10 hours of the first, and the first coat of bottom paint goes on when the epoxy is still soft enough to leave a fingerprint if you press on it.

Donna said:

The hot pepper does nothing and adding copper powder in the U.S is illegal.

Click to expand...

It is not illegal to add copper to your anti fouling paint but it is likely ineffective. Adding pepper is absolutely useless.

After a sandblast to bare metal and 5 coats of Interprotect 2000 (alternating btwn white and gray), we applied 3 coats of Trinidad Pro in May 2017. Then had a little Irma damage in September, so hauled out in December, and had to put another two coats of Trinidad Pro on, for the simple reason that it can't dry out, or you have to recoat it. (72 hours or more hauled out is their cut-off.) We've been in the Bahamas and Turks and Caicos since then, and have been happy with the results (we clean the bottom ourselves). However, I'm not sure Bahamas and Turks are good places to gauge bottom paint - there doesn't seem to be a lot of stuff here that wants to grow on boats, pilings, etc.

gahmadi said:

Need to bottom paint my KK-39. The choices are hard paint or self polishing paint, specifically Pettit Trinidad PRO or Cukote respectively. I need to decide which is the best option and why? I would appreciate any experience-based advice.

Thank you

Click to expand...

I purchased my boat 5 years ago in Annapolis, Hartge's Yacht Yard used Interlux ultra (Black) during commissioning. The boat is year round in the water with an annual haul to wash and inspect and have not had to repaint or touch up. We are in northern waters and don't have the same growth as you have south of here but it works better than anything that I've seen on any other boats in our area. Unfortunately it is not available in Canada.

Sea Hawk shark hard covered with sea hawk ablative. Nothing better anymore.

Two coats of Sea Hawk epoxy barrier and two coats of Sea Hawk Shark Skin bottom paint. Pettit zinc spay to the propeller.

BrianSmith said:

After a sandblast to bare metal and 5 coats of Interprotect 2000 (alternating btwn white and gray), we applied 3 coats of Trinidad Pro in May 2017. Then had a little Irma damage in September, so hauled out in December, and had to put another two coats of Trinidad Pro on, for the simple reason that it can't dry out, or you have to recoat it. (72 hours or more hauled out is their cut-off.) We've been in the Bahamas and Turks and Caicos since then, and have been happy with the results (we clean the bottom ourselves). However, I'm not sure Bahamas and Turks are good places to gauge bottom paint - there doesn't seem to be a lot of stuff here that wants to grow on boats, pilings, etc.

Click to expand...

I queried the Paxton sales rep on 72 hour limit out of the water. The surface of the paint oxidizes or something to that effect. The solution is to abrade the surface with a Scotchbrite pad. As I will likely be hauling out end of next summer, I plan to try the equivalent of the Scotchbrite pad on a slow variable speed buffer to refresh the surface.

Ted

O C Diver said:

I queried the Paxton sales rep on 72 hour limit out of the water. The surface of the paint oxidizes or something to that effect. The solution is to abrade the surface with a Scotchbrite pad. As I will likely be hauling out end of next summer, I plan to try the equivalent of the Scotchbrite pad on a slow variable speed buffer to refresh the surface.

Ted

Click to expand...

Yes, I didn't mean to imply that you have to do anything extraordinary after being out of the water for 72 hours. Just a good roughing up of the surface, for the next coat. With ablative paint, you don't have to recoat after a haulout, should you have to haul out for 3-4 days sooner than expected. That was the point I was trying to make.

BrianSmith said:

Yes, I didn't mean to imply that you have to do anything extraordinary after being out of the water for 72 hours. Just a good roughing up of the surface, for the next coat. With ablative paint, you don't have to recoat after a haulout, should you have to haul out for 3-4 days sooner than expected. That was the point I was trying to make.

Click to expand...

No, you misunderstand me. You can scuff the surface and put it back in the water without repainting the bottom.

Ted

O C Diver said:

No, you misunderstand me. You can scuff the surface and put it back in the water without repainting the bottom.

Ted

Click to expand...

Oh! I'm going to have to look into that the next time we have to haul out before we need bottom paint. Thanks!