bottom paint peeling

[Bob 04 H260]

I live in Canada and bought a boat last Feb in Florida. We had it hauled and put on stands down there for the summer. When we bought it, we had it hauled for the survey the bottom looked clean so assumed bottom paint was OK. When it was hauled for storage and had dried out for a few days some of the bottom paint started to flake off.

I just got an email from the yard advising a lot of the bottom paint is flaking off and it really needs to be stripped bare and redone. They felt if it was just given a coating of paint it would continue to flake and so would only last one season.

It did not appear to have a thick buildup of paint on the hull.
What is a fair price to strip the bottom of a 36ft boat and apply a good quality anti-fouling paint ?

Picture below is the hull when it was hauled for the survey.
Bob

 

[zeehag]

bottom paint can only be dry and out of water short time, even when brand new.
old bottom paint is no good and needs to be stripped of and re applied to work. yes it does peel and chip and come off easily. that is how ablative paint works...

 

[Sumner]

Bob sorry to hear that. Are they or you saying strip the paint all the way off to the gelcoat or just take enough off to get to a good solid base? Also does the boat have barrier paint on it. If so you would just want to go down to that paint and not past it.

As you know we had our paint stripped all the way to the gelcoat for blister repair. I got a bid from a crew in the yard that does lots of bottom painting and does good work. They wanted $2400 just to sand all the old paint off.

Then I got a bid from a fellow that blasts boat bottoms for a living for $1200-$1300. Since he had good recommendations I gave the job to him and if I remember right he came in a little under his bid (the only one so far). He did a great job and ends up with just a little blush of paint when finished. Then I had the other crew do the blister repair, not cheap, but I think they were fair and did a great job.

Now I still have to put on the barrier coat and the bottom paint when we return.

The above prices did not include paint or labor to put the paint on. If you take the bottom down to the gelcoat I'd recommend putting on a barrier coat while you are at it. It isn't cheap but would be a lot cheaper than fixing blisters in the future. The barrier paint we used is $120 for a 2 gallon kit and the anti-fouling we used is about $180 a gallon. We are going to have about $1500 total in the barrier and anti-fouling (3 coats of barrier (equivalent to 6-9 coats of other barrier paint) and 2 1/2 coats of anti-fouling. Black under the Blue. We will know to put on more when we wear through to the black. An extra coat around the waterline.

Will the yard let you do the work? If so maybe have someone strip it, but don't go any further. That would also help with drying the hull out if for any reason it needs it. Then you apply the paint yourself when you go down. That part isn't real hard.

We are using the same paint that we used on the Mac....

http://purplesagetradingpost.com/sumner/macgregor2/outside-39.html

...except putting on 3 coats of barrier paint which is the max Sea Hawk recommends. If you read the link you can see what we used. We will stay with the ablative paint since the boat is like a trailer boat in that you need a paint that can come out of the water and go back in months later. Most hard paints are not designed to go in and out. We had good luck with the paint we used in Florida with the Mac and someone on this board recommended it for Florida.

If the ablative is put on right it should wear off, but not flake off. The key with the whole deal is prepping the surface right and then applying it in the correct time windows so that subsequent coats of barrier or anti-fouling develope a chemical bond between coats.

Good luck,

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[Bob 04 H260]

Thanks for the advice. I did barrier coat a previous boat and was quite pleased with the results. This boat has a blister protection below the waterline that would be lost if I had it sanded down or blasted. I think they recommend a chemical stripper if required. I am going to have someone have a look at it for me before going any further with the yard.
My understanding was most cruisers that haul each year recoat the bottom before it gets put back in.
I talked to Pettit a few months back about their ablative paint and they claim it can be used without recoating each year on a boat that is hauled for the summer. They suggested a light rub with a scotch brite pad just before launch to expose some fresh copper.
The peeling that I saw last spring revealed a lighter shade of blue underneath. I think worst case maybe sand off the dark blue antifouling and recoat. As long as it is not sanded down to the gelcoat I don't think it should need a barrier coat.

Bob

 

[Sumner]

Thanks for the advice. I did barrier coat a previous boat and was quite pleased with the results. This boat has a blister protection below the waterline that would be lost if I had it sanded down or blasted. I think they recommend a chemical stripper if required. I am going to have someone have a look at it for me before going any further with the yard.
My understanding was most cruisers that haul each year recoat the bottom before it gets put back in.
I talked to Pettit a few months back about their ablative paint and they claim it can be used without recoating each year on a boat that is hauled for the summer. They suggested a light rub with a scotch brite pad just before launch to expose some fresh copper.
The peeling that I saw last spring revealed a lighter shade of blue underneath. I think worst case maybe sand off the dark blue antifouling and recoat. As long as it is not sanded down to the gelcoat I don't think it should need a barrier coat.

Bob

Hi Bob, if it has blister protection then I would take that to mean an epoxy barrier paint unless there is something else I haven't heard of. Yes you wouldn't want to sand through that. They could sand the anti-fouling off down to the barrier paint without taking it off and I think even the guy that does the blasting could do that. He has a lot of control. Not saying you should do that, but I did see them sanding boats like that at the yard.

Sea Hawk said the same about their ablative paint so think the scotch brite is a pretty universal thing to do with the ablatives after they have been out a while.

I think the second opinion is a good idea. Is the yard telling you that they can't have the paint flaking off due to an environmental deal or are they just saying that they could work on it for you?

We bought 4 gallons (2 black and 2 dark blue) of anti-fouling/biocide (for slime) to do the bottom and think that will be plenty to do the 2 coats and some extra at the water line...

http://www.bottompaintstore.com/blog/paint-calculator/

...and leave us some extra for touch-up.

Good luck,

Sum

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[Manureva]

i have used the eco friendly aqua gard on my boat, it is good for 12 month out of the water. So far after one year of using it in salt water (cold water in nortern new brunswick). there was no noticable growth under the boat, the rudder and outboard who where in the sun a lot got some growth. so any surface not directly exposed to the sun will be allrigth.

I recomend the aqua gard product for its longeviety out of the water and for it environementaly friendly performance.

 

[RichH]

If the original paint was an ablative the flaking sometimes results when the total thickness of repeated layers becomes too thick. IMO, the 'down deep' layers lose their adhesion causing all layers to flake off. My experience is that if any ablative build up over ~0.050" thick then flaking is a possible result.

When this happens on my boats, I take a sharp chisel and starting in the 'crater' work the paint in larger and larger 'craters' until I find where the adhesion is adequate. I then fill the craters by sanding (leaving the edge and not fairing the edges) then filling with new bottom paint thickened with micro-balloons or colloidal silica... simply building back the thickness of the flaked-off layers. I simply use a polyethylene trowel and 'fair' the thickened bottom paint into the 'crater'. Once filled and the paint has a time to 'cure' (~1 month), then I sand down to a 'reasonable' thickness. The finish step is trowel-fairing with unthickened paint. Such 'repair' will last another 5-6 years until the paint develops adhesion problems.
With ablative paint if you allow the total thickness to become over about ~0.050" thick Ive found that 'flaking' WILL occur. Best with any ablative is to not 'over-do' the thickness and only paint when you NEED to; just lightly sand the surface if there still is 'plenty' on the hull and don't slavishly keep on putting more and more over the 'old' coating.

BTW ... my usual application method for ablatives is NOT using a 'roller'; I apply with a polyethylene trowel to fill surface roughness and get a 'baby's ass smooth' application. If I do need to apply normal thick layers, I apply with a foam (WEST) roller and 'fair' that with a poly trowel. This prevents excessive 'thickness' build up and lessens the eventual 'flaking' .... and I use MUCH LESS paint. Such smooth applications are faster, release slime better .... and seemingly last a LOT longer than that applied with roller.

 

[shemandr]

Best with any ablative is to not 'over-do' the thickness and only paint when you NEED to; just lightly sand the surface if there still is 'plenty' on the hull and don't slavishly keep on putting more and more over the 'old' coating.

Yes!
I had this discussion with the yard manager where I am no longer wintering my boat. I only want them to touch up (And please prep the area). They want to paint the whole bottom every year. Too much paint buildup! They say, "But it wears off." Not evenly.
Look around at boat bottoms and its easy to see that the ones with many layers of paint have the nasty rough bottoms with the flaking. After a few years they need the expensive bottom job. I don't mind scrubbing the bottom a few times a summer to avoid that.

 

[Nom De Guerre]

You are correct in that you may not need to strip bare and re-do the whole thing. Are you sure that the bottom paint job done just prior to purchase was done with paint compatible with what was previously on there? If it was done with a hard paint over ablative (to save on seller cost?) then it's likely you can just go down a layer and overcoat with something compatible.

The yard may be playing it safe and avoiding guessing games that come with the potential for a repeat of the flaking issue and an unhappy customer.

Unfortunately I can't provide an opinion on a fair price as I've never looked into the cost for such a job.

 

[BobD17833]

micro-balloons or colloidal silica

Rich,

I have many chipped, flaking areas that will need re-finishing. I am not going to scrape or strip, as these typical areas re-occur every year.

When I read your post looking for repair options and proceedures, the reference to - micro-balloons or colloidal silica - left me puzzled.

What is this/are these?

Bob D
Boston

 

[Barnacle Bill]

Zeehag has given you some erroneous info, or perhaps not enough. Basically there are single season paints and multiseason paints. The single season paints usually have cuprous oxide toxicants and those toxicants sluogh off as the boat moves through the water, leaving the paint behind. Eventually you will not have toxicants left in the paint, but the paint will still be on your hull. Usually these kinds of paints, because they have to be recoated annually (because your boat comes out of the water for winter), will get a build up of paint, which eventually will require removal. The other thing about cuprous oxide paints is that there is a chemical change that takes place when the boat is removed from the water and the hull dries. That is why these are not recommended for boats that are trailered. A multiseason paint has toxicants that slough off with the paint, so that eventually the entire application will disappear and the hull will be bare, but usually it is advised that when you start seeing bare hull, it is time for a recoat. There is no adverse toxicant problems when a multiseason paint on a boat that is hauled, therefore they are recommended for trailerable boats. You can pull them, let them dry and put them back in the water and they will work just fine. So, if you see an old application with a cuprous oxide bottom paint, you cannot assume there is good toxicant in the paint even though you see paint. With a multiseason paint, if you see paint, you know it will still work for you. Multiseason paints, like Interlux' Micron technology, has sort of a time capsule approach to antifouling. The paint and the toxicant leech away at the same rate, so it is working for you until the paint is gone, which means you can get by with less percentage of toxicant because it keeps releasing what it has as the paint sloughs off. Paint price is directly related to toxicant percentage and also the type of paint it is. Higher percentages of toxicant, like in Trinidad or Ultra, are more expensive and Micron paints are more expensive too. But, single season paints are usually a two coat application, per recommendation and the multiseason paints are 3 coat recommended. But, since multiseason paints last longer, you don'thave to do the job as frequently, so you save money elsewhere, especially if you pay someone to do it. To further address the paint flaking off......this probably is due to either incompatibility of paints (two different types that don't adhere well), or to improper preparation, such as not sanding properly so that there is no tooth for the new coat. Hope this helps you with insight as to what is going on with your boat.

 

[catsailor]

Sorry zeehag, a little off base.

I've owned 2 boats I kept in the water, each of which had 15-20 years of soft paint on them. The first was still smooth enough to make 20 knots during sea trials when I sold her. There is a trick.

If you keep the boat in the water for 3-6 months and then haul for the off season, you aren't wearing paint off. Cheaper single season paints do harden, you repaint, and the paint becomes thick and unstable.

On the other hand, I use 2-year paints, scrub just a bit to stretch them to a practical limit, repaint as needed with some sanding (not stripping, but a good overall sanding with a vacuum orbital sander), and relaunch. I stay in the water all year. Thus, the paint is completely used up each time, does not build, and removal is never needed. Perhaps this practice is impractical in much of Canada.

As for the OP, does it need done now? Take a look. Realistically, a conventional paint will only last a season anyway, so roll the dice if you like. But I'm guessing you won't scrub or do any of your own work, so you get to pay yard bills. That's OK too.

 

[fstbttms]

Zeehag has given you some erroneous info, or perhaps not enough.

No, it's erroneous. All of it. She doesn't make a single accurate point in her post.

 

[Bob 04 H260]

I had the bottom inspected and some pictures taken.

The advice I am getting from Florida is go ahead and launch in the boat in January as is. We will only have her in the water until May. We will then have her hauled for the summer in a yard where I will have the option to do the work myself. At that point I will call in a dealer or rep from Pettit for advice on what product to use and how the bottom should be prepared to receive it.

I'm told it is falling right off just sitting there. There appears to be a solid intact coat of bottom paint beneath the paint that is flaking off.

I appreciate all the good advice provided.

Here are couple of pictures.

Bob

 

[xcyz]

You should be fine. Have the diver that cleans your bottom keep a eye on it and the good news is, he will be scrubbing off the failing paint as he goes...

 

[Maine Sail]

bottom paint can only be dry and out of water short time, even when brand new.

That is only true for some bottom paints, usually hard paints. It is not universally true for all paints. Many paints today, including most of the ablatives are haul / re-launch capable. Here in the NE many folks are out for 8+ months. A light scuff with Scotch-Brite re-activates the paint.

old bottom paint is no good and needs to be stripped of and re applied to work.

This may or may not be true and is NOT TRUE for all paints. It all depends upon what type of paint was on there.

yes it does peel and chip and come off easily. that is how ablative paint works...

No, that is absolutely NOT how ablative paint works. Ablative paints SHOULD NOT PEEL and flake off. I have seen well done bottom jobs with no peeling at the 15-20 year mark and poorly done jobs peeling after one season. Of course the 15-20 year boats have also had proper care and have not been treated like a "hard paint" boat. The paint was not allowed to build up thickness and just enough is left on the boat for protection.

Ablative paint should slough off or wear way but it should never peel or flake unless applied incorrectly or incorrectly used and too many coats have been applied.. Peeling or flaking paint is usually a sign of an improper application or improper use of the paint.. Lack of dewaxing the surface, lack of sanding and dewaxing, lack of properly hot coating over an epoxy barrier coat, allowing an epoxy barrier coat to kick then not washing it and properly sanding it are all reasons why paint can flake. Properly applied it should not flake or peel for many years. Applying a paint over another that is not compatible with the new paint will result in what the OP shows.

Hard paints with build up will eventually begin to peel & flake, with multiple layers, but a hot coated ablative directly to barrier coat can easily go 15-20+ years if properly cared for and properly applied....

 

[BobD17833]

MS,

I need a quick prep procedure for the spring re-paint. I'm flaked/peeled off in many large hull areas/spots that I've been just painting over every spring. The flaked areas are down to gel coat.
How do I prepare the flaked off area for new paint?

Bob D
Boston

 

[Maine Sail]

MS,

I need a quick prep procedure for the spring re-paint. I'm flaked/peeled off in many large hull areas/spots that I've been just painting over every spring. The flaked areas are down to gel coat.
How do I prepare the flaked off area for new paint?

Bob D
Boston

Until you strip it just de-wax the bare spots, then sand, then paint.. Often times peeling can be the result of improper dewaxing at the time of commissioning.

I did not let the dealer do our new boat when we bought it in 2005 because I did not trust them to do a "proper" job. I went through three gallons of dewaxer, 144 rags and a bunch of sand paper.... She was dewaxed no less than 5 times during the procedure. Proper prep for the first bottom paint on a new boat is 250% critical and it is very, very often done incorrectly. The paint may stick for a while but eventually it lets go..