Hard Bottom Paint

As you may know, Skinny Dippin' is getting a "bottom reset". Media blasting the 20+ years of old paint off and getting a fairing a barrier coat applied. We have a unique and rare opportunity to change paint types. Since the first layer after the barrier coat is going to be hard bottom paint, we are strongly considering just using a second coat of hard paint and calling it done. Then we'll see what performance we get out of it. In the past we have exclusively used the cheap stuff (CPP+) from Worst Marine, but have applied is annually to stay on top of things under there. We liked it, but know we can do better.

I'm interested is seeing what you guys have to argue about... errm... umm... I mean... what wonderful contributions y'all have on the subject. It seems to me to be worth a shot. We can always go back to ablative if we need to, but can never try hard again if we start there now.

Thanks,
Tom-

We have been using Pettit Trinidad SR. We have always gone at least 2 years before repainting and have gone as many 3.5 years. It has one of the highest cuprous oxide contents and has worked well in warm waters.

Larry M said:

We have been using Pettit Trinidad SR. We have always gone at least 2 years before repainting and have gone as many 3.5 years. It has one of the highest cuprous oxide contents and has worked well in warm waters.

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We have used the Pettit Trinidad SR as well. We are in the same marina as Skinny Dippin. Our last sailboat was three years when we hauled it and it had three barnacles on the whole bottom. Stella now has 2.5 years and will need to be done this spring.

I think not using an ablative on slow boats is a mistake unless you have the money to blast whenever the bottom paint starts to fail from buildup.

I have had Pettit ablatives "not ablate" 2 times in the past so they will never go on my boat again.

This year I used Interlux Fiberglass Bottomkote NT and it has worked as well or better than anything I have ever seen except tin based stuff. My boat doesn't move much during the summer but is in a 1-3 knot tidal current.

It seems to be getting good reviews and is one of the more inexpensive paints on the market. It may have some unusual dry out requirements so make sure you read all the issues with it...but for an all year round in the water boat...it seems to be a winner.

Larry M said:

We have been using Pettit Trinidad SR. We have always gone at least 2 years before repainting and have gone as many 3.5 years. It has one of the highest cuprous oxide contents and has worked well in warm waters.

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That's what my diver recommended so that's what I used. I've since realized that this just makes his job easier as he charges the same for each cleaning regardless of the level of fouling.

One disadvantage of this paint is that it must stay in the water and any haul out over 72 hours will "kill" the paint.

I am considering some of the non-copper options for the next painting.

We had InterLux Micron Extra for at least 3 years and it performed very well but it is marketed as ablative and it certianly IS NOT. In these pics you see a friend helping me scrape the old stuff off. He was working at the stern and me fwd. It had a build of about .050" and was not in good shape so needed to come off. I'll NEVER use it again.

I noticed in a store in CRaig there was about 25 cans of Pettit Sea Mate paint like ther'e expecting a run on the paint. Never saw any other bottom paint on the island and never saw a fisherman scraping his bottom. So we switched last year. The fishermen all go on the grid and slop more on every year ... not what you'd call ideal preparation for the paint and not recommended on the can either but they all used it and it works well.

In this case old methods used in the 50s and paint that is probably only slightly different than what we used in the 50s did the job. Now I'll not go back to the InterLux Micron Extra as I don't ever want to scrape again. And we don't have tidal grids so I'll either have to haul the boat every year or find a higher performance paint that does NOT build.

psneeld said:

..I think not using an ablative on slow boats is a mistake unless you have the money to blast whenever the bottom paint starts to fail from buildup...

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You're right about the build up but ablatives don't hold up to regular bottom cleaning which for us is monthly. The one time used an ablative, we had to haul in less than 18 months for all the paint was gone. Hopefully someone will develop an ablative that is as effective as the TBT paints were.

rwidman said:

That's what my diver recommended so that's what I used. I've since realized that this just makes his job easier as he charges the same for each cleaning regardless of the level of fouling.

One disadvantage of this paint is that it must stay in the water and any haul out over 72 hours will "kill" the paint.

I am considering some of the non-copper options for the next painting.

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So let me see if I understand. Using that logic don't brush your teeth everyday because it makes it easier for your dental hygienist to keep your teeth clean and she needs to earn her money. Makes sense to me. If it makes it easier for your diver then it must be working. Am I missing something?

Where does the 72 hour rule come from? Not that I haul my boat regularly for 73 hours. A lot of things can be taken care of in 72 hours. Anything major might take longer but then you would have to repaint and that may be the cheapest part of the haul out.

Otherwise it worked satisfactory?

JD said:

We have used the Pettit Trinidad SR as well. We are in the same marina as Skinny Dippin. Our last sailboat was three years when we hauled it and it had three barnacles on the whole bottom. Stella now has 2.5 years and will need to be done this spring.

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From day one we have used Pettit Trinidad as well. However we little sand the bottom first, so there is no build up and the new pain has something to stick to. We go three years in the salt and 5+ year in fresh and salt. The only place we get growth is on the running gear and maybe the keel/hull where the blocking and supports where.

Wasshington state regulating agaist high copper paint so we will have to go to Canada to buy the bottom paint and/or have to pull.

I pretty much use bottom paint so I DON'T have to have my bottom cleaned regularly.....

Gonzo:
Based off of personal experience, you need to be careful with timing when you repaint. AFTER purchasing our boat it sat on the hard for a few days, during which bottom paint started dropping off in large flakes. All of the paint "alligatored". The Interlux rep. said the problem resulted from poor timing during application. Turns out you need to apply the second barrier coat while the first is still tacky, then apply the first coat of antifouling while the the second barrier coat is still tacky. Anything less and you risk failure!! Good luck. BTW, following the recommended procedure we have had no problem for the past 7 years.

I Believe the trick is in the antifouling paint application within a specified time to get a good chemical bond to the interprotect barrier coat. The barrier coats can be applied over top one another up to 6 months so they don't have to be tacky...I just did mine this spring and just rechecked the product literature...it's the bottom paint application that's finicky. not the barrier coat coats...

The attached photos are my bottom today after being in a heavy fouling area since the beginning of June with no scraping and only one 60nm round trip to escape Hurricane Sandy. Used Interlux Fiberglass Bottomkote NT...just bought another gallon for $75 to touch up before I head south.

psneeld said:

I Believe the trick is in the antifouling paint application within a specified time to get a good chemical bond to the interprotect barrier coat. The barrier coats can be applied over top one another up to 6 months so they don't have to be tacky...I just did mine this spring and just rechecked the product literature...it's the bottom paint application that's finicky. not the barrier coat coats...

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The instructions for the barrier coat I used said subsequent layers (of epoxy barrier coat) should ideally be applied within the chemically "open" window for the epoxy...typically about a week. If the epoxy fully cures (after that chemically open window closes), then the surface should (must?) be roughed with 80 grit prior to subsequent coats (of epoxy). At that point the epoxy to epoxy bond is mechanical, although fresh epoxy adhers well to a roughed epoxy surface no matter what.

Agreed that the first layer of bottom paint should go on while last coat of epoxy is still tacky....for a one or two person crew, that normally means doing the bottom in sections....last layer of epoxy followed about 30 minutes later by the first layer of bottom paint. We did that step on a 45 footer in four sections. Used a hard, red colored first coat of bottom paint as a guide coat for subsequent coats of black ablative. All products were from the same manufacturer.

Interlux techies also recommend that subsequent coats of bottom paint be applied within a specified time window for best chemical bond...particularly applicable if you're covering a first coat of hard bottom paint with subsequent ablative coats. Interlux web site has some very helpful charts and tables that cover all of this and a great tech staff who were easy to reach. Their web site also identified which paints lose their antifouling properties when the bottom is allowed to dry on the hard. I do not recall any hard bottom paints that would reactivate after drying...but not positive about that. This is a very big deal on the Great Lakes as the boats are hauled every winter. On the other hand the fouling problem is not all that bad, and power washing the ablative every year is hard on the paint. I do not allow inexperienced yard crew to power wash the boat for that reason...I prefer do it myself.

By the way, I sense that the term barrier coat might mean different things to different people. Per my understanding, anything other than epoxy, or possibly a vinyl ester coating over a polyester bottom is not considered a barrier coat.

All I can say is read the product literature very carefully ...there are min and max overcoating times...the web site says up 6 months to overcoat with interprorect 2000...please direct me to the place where it says something different as I'll need it to go back to interlux if my coating has issues.

Boat yard is aware of the proper application. I asked.

I pretty sure the yard is planning to use Petit Trinidad SR, but I will confirm.

Thanks y'all.
Tom-

If using an Interlux barrier coat...you may want the initial tie coat to be interlux also. Just because a yard said they knew what they are doing is one of the biggest mistakes boat owners make every day.

They are using Sea Hawk barrier coat.

Until earlier this year we used Petit Ultima SR on our boat. This is an ablative (sloughing) paint with an anti-slime element in it. We normally haul every two years for bottom paint but we have gone as long as four (not because we wanted to but because my work travel schedule forced it). By the end of four years the paint was pretty much shot but it was still doing its job to a surprisingly effective degree.. However we use our boat year round so that helps wash off the baby barnacle larvae and such.

This year we changed paint, not because we were dissatisfied with the Ultima SR but because the yard no long stocked it, although they could get it. So we decided to use their equivalent paint. I don't even remember what the brand name is but it was considerably less expensive than special ordering the Ultima SR. It does not have the anti-slime properties of the Petit product but that has not proven to be much of an issue so far.

Divers cannot wipe down bottoms in our marina (a rule enacted several years ago for environmental reasons). Our plan is to haul again in the spring of 2014 so we'll see how this brand of paint does. We've been told by other boaters who use it that it does a good job.

One caution about the Ultima SR--- it has a very high copper content and is prone to "burning" in situations that promote that.

Our boat had hard paint on it when we bought it. You can put ablative paint on over hard paint but you cannot put hard paint on over ablative paint. So if we wanted to change to hard paint (we don't) we would have to have the bottom stripped back to at least the barrier coat if not the gelcoat.

I've been using Petit Trinidad SR for decades and I get an easy 5 years out of it. I also have it on my dinghy, and it's approaching 8 years with no fouling. Good stuff!

psneeld said:

All I can say is read the product literature very carefully ...there are min and max overcoating times...the web site says up 6 months to overcoat with interprorect 2000...please direct me to the place where it says something different as I'll need it to go back to interlux if my coating has issues.

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Interesting...I just looked at the Interlux site, pro section, and the general info pages for 2000E states overcoat time of up to two weeks. Then I looked at the data sheet and it does say six months (which I don't recall from when we last used it several years ago). In any case, their tech guys told me that sanding was advisable after the two week "open" period. I know that Dupont and PPG have the same general guideline for their automotive epoxy primers as I used them on my Jag restoration. I doubt you'll have a problem, in any case.

Some thoughts from a professional hull cleaner:

1.- Pettit Trinidad is overall, the best anti fouling paint available in the U.S., IMHO. Excellent anti fouling properties and durable as hell. Micron 66 is an excellent paint as well, but being an ablative, not as durable as Trinidad. Great stuff on powerboats though.

2.- There is no anti fouling paint available in the U.S. that does not need regular cleaning in regions of moderate to high fouling. If you feel your boat does not need cleaning, you are either using it with a dirty bottom or it lives in an area where fouling is very low.

3.- Most copper-based hard paints are compatible with most copper-based ablatives. This means hard can go over ablative and visa versa. It's all in the preparation. There is no hard-and-fast rule, such as "hard paints can never be used over ablatives."

4.- All copper-based anti fouling paints release their biocide at a proscribed rate until that biocide is reduced to an ineffective level. Typically this takes 2-3 years. This is how they are formulated to work. Exorbitant claims of paint performing well 3 or 4 times this long are not to be believed.

5.- Regular cleaning of an effective anti fouling paint (like Pettit Trinidad) will make your diver's job easier. It also means you will be getting better performance from your boat, reduced fuel consumption, carbon emissions and wear on your engines. How anybody could construe that as the diver trying to get over on the boat owner is beyond me.

Matt
Good to hear from you. You took care of my 28' in Alameda (Marina Village) for years until I brought it up to the PNW and put it in the Columbia. I switched back and forth between salt and fresh a couple of times a year and that did a pretty good job of stretching the paint way past its normal useful life -- but when I sold the boat the buyer wanted an allowance for new paint since it was six years old.

Ahh, another satisfied customer.

What was your boat named?

Ahh... Thanks Matt. Good stuff. Glad you replied to this.

Tom-

Matt
Paradise II, slip A-3, gate 8, Marina Village.
I also enjoyed your video of an underwater prop change, it was great!
Your info on the paint is much appreciated, I'm just about due now.

fstbttms said:

3.- Most copper-based hard paints are compatible with most copper-based ablatives. This means hard can go over ablative and visa versa. It's all in the preparation. There is no hard-and-fast rule, such as "hard paints can never be used over ablatives."

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Interesting. You are the ONLY person I have heard in 14 years of owning our boat who has claimed this. Yard owners and managers, dive services, paint reps from Petit we have talked to, etc., etc., etc., all say exactly the opposite.

Regarding cleaning a boat's bottom while it's in the water, this is actually illegal in our marina and possibly other marinas in Puget Sound and has been for several years now. Divers can change zincs, knock off barnacles, inspect running gear, and make whatever underwater hardware repairs may be required, but they can no longer wipe down boat bottoms. The reason is environmental.

Marin said:

Interesting. You are the ONLY person I have heard in 14 years of owning our boat who has claimed this. Yard owners and managers, dive services, paint reps from Petit we have talked to, etc., etc., etc., all say exactly the opposite.

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There are many sources of misinformation out there- hull cleaners, boat yards and boat owners chief among them (present company excepted, of course ) And I find it difficult to believe that a Pettit sales rep told you that hard paints cannot go over an ablative:

Pettit Compatibilty Chart


Interlux Compatibilty Chart


West Marine Compatibilty Chart

Marin said:

Regarding cleaning a boat's bottom while it's in the water, this is actually illegal in our marina and possibly other marinas in Puget Sound and has been for several years now. Divers can change zincs, knock off barnacles, inspect running gear, and make whatever underwater hardware repairs may be required, but they can no longer wipe down boat bottoms. The reason is environmental.

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In-water cleaning of ablative paints is illegal in Washington. Other paints can be cleaned. While your particular marina may have restrictions regarding in-water hull cleaning above and beyond what the state has legislated, that does not mean it is illegal. It simply means it is against the rules in your marina. You are correct however, in that the reason behind all this is environmental. Whether that is indicative of a true regard for protecting the environment or merely reducing the marina's potential legal liability is what is unknown.

Marin said:

Regarding cleaning a boat's bottom while it's in the water, this is actually illegal in our marina and possibly other marinas in Puget Sound and has been for several years now. Divers can change zincs, knock off barnacles, inspect running gear, and make whatever underwater hardware repairs may be required, but they can no longer wipe down boat bottoms. The reason is environmental.

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Maritime Authority here disapprove of barnacles knocked off in the water, though the process attracts hungry fish. I can swim and pee(far too much info) but can`t pump it thru a head.
Better hull cleaning divers here use compressed air to blow build up off the antifoul. Brushing the antifoul surface usually ended its effectiveness but cleaning with air jets is much kinder to it. Is that allowed in Puget Sound?

BruceK said:

Better hull cleaning divers here use compressed air to blow build up off the antifoul.

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Surely you jest.

Marin said:

........... Regarding cleaning a boat's bottom while it's in the water, this is actually illegal in our marina and possibly other marinas in Puget Sound and has been for several years now. Divers can change zincs, knock off barnacles, inspect running gear, and make whatever underwater hardware repairs may be required, but they can no longer wipe down boat bottoms. The reason is environmental.

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I have my boat's bottom cleaned by my diver ten times per year (more or less) at a cost of $62 plus any anodes, etc. If I had to add the $90 haul out charge to each of these cleanings, I would find myself another marina. Or have it done at night when no one is around. In my area, not cleaning the bottom of a boat that's kept in the water is not an option if you want to use it from time to time. Friends with planing hulls tell me that they sometimes cannot get on plane if the bottom and running gear hasn't been cleaned in a month.

I'm thinking, at least as far as boating is concerned, Washington State is the new California. You might want to consider some lobbying eforts while it's still legal to keep a boat in the water there.