Bottom Paint Advice Needed

S

Solesurfer

New member
Hello,
We have a 25' Classic cruiser in Southern California. We put the boat in a slip for the 3 or 4 summer months. Otherwise we mainly keep the boat on a trailer and stored in a garage.
We purchased it a couple years ago and after last years haul out I noticed that the paint has been, what appears to be, cracking off. Now I'm researching bottom paint and trying to do it myself. My local boatyard will put my boat on stands for $275 and I can work on it myself.
I'm getting ready to prep the bottom. I've come to the conclusion that this is an ablative paint as it rubs off and modified epoxy(I've heard) retains its hardness and stays on. My question is should I powerwash/scrape/scrub off the old paint before applying the new paint? Or can I/should I paint over it to have even more protection? The majority of the paint looks clean, but I suspect with a scraper, junks will come off.

I've attached some pictures of what it currently looks like.

Thank you,
Tom
http://imgur.com/a/KcZdb#2
 
I would try to water blast the old bottom paint off. With the grey underneath, it suggests that there was an epoxy barrier coat--which is good. It should should not peal off.

You can use scrapers, but they can harm the gel coat if you are not careful. There are also strippers, designed for this and are also a good amount of work. Bottom paints can be toxic, so you need full suit and respiratory protection. In many areas of Calif. You have to capture all sand dust, or even material which you removed--as toxic waste. See what your boat yard's policy is on this. Some areas will allow you to collect material with blue tarps.

It does sound as if you have ablative paint--and you should only put ablative paint over this. I am not familiar with what bottom paints are both available and legal in Calif, because of regulations. Some are water base. Some areas are either banning or talking of banning copper based toxins in the bottom paint.
 
As Thataway says, there are "rules" about which bottom paints can or cannot be put over which other ones. Not rules as in laws, but rather because some won't adhere properly to others. As a general guideline, a harder paint cannot be put over a softer one; and nothing can be put over a vinyl paint. West Marine has had good charts showing what can be put over what (or not). Also likely Interlux or Pettit (or other mfgrs.) will have guides to this.

You are right to put some effort into prep work, as that is often what makes the difference between a good or prematurely failing job.
 
I suggest you power wash the bottom.

Then use a 90 or 100 grit wet/dry sand paper and sand the bottom using water and smooth out the areas that may have chipped away.

Be very careful not to sand to hard or intensive in one area because you could sand through any barrier coat or if not through the gel coat.

The purpose of sanding is to prepare the surface for the new coat of paint.

If you have an ablative paint currently on the bottom then you CANNOT put a hard shell paint on without removing all paint. That is why it is better to use Micron CSC. This paint will go over any ablative paints but will also go over any hard shell paint.

If you take your boat out on the trailer for periods greater than a week then you must use CSC because any other paint will lose its properties if out of the water.

Now having said all that it is true that in the USA you have paints we cant get here so my last statement refers to paints available in Canada.
 
rainger":2r0g22q1 said:
If you take your boat out on the trailer for periods greater than a week then you must use CSC because any other paint will lose its properties if out of the water.
Click to expand...

It's true that there are some paints that can "dry" for extended periods of time without losing their efficacy, and others that can't. But the former category is not limited to CSC, nor even to ablative paints. It is a good thing to be aware of though, so as not to use an inappropriate paint.

What I consider when choosing a bottom paint:

1) Do I need or want bottom paint at all?
2) Is this a go-fast or a slow boat?
3) Will it be out of the water for extended time periods?
4) Will it be in the water but not moving for extended time periods?
5) Is there already bottom paint on the boat, and if so what kind (compatiblity)?
6) What is most effective in my local area, presuming the boat mostly stays local?
 
Good prep is the key to any paint job, just like at home. Don't paint over poorly adherent old paint. Sunbeam has some great points, as always Dr Bob. Concur a commercial grade power washer and a bit of wet sanding should get off most all of the old ablative paint and probably your epoxy barrier coat is OK. It's traditional to use a contrasting color for epoxy barrier and any bottom paint so your neighbors can tell you when it's wearing off. There are many other trailer boat choices although I had good results with Micron CSC and Micron Extra.
I called Defender and tried a relatively new product, Pettit Hydrocoat SR, $184/gal before $20 rebate...water-based, simple soap and water cleanup. Used rollers, brushes, drop cloths etc are nontoxic and can go in the regular trash.

http://www.defender.com/product.jsp?pat ... id=2197663

It's not on the link Dr Bob provided, and that expert makes some good points in favor of hard paint for your area.
I used 4" mini rollers 3/8" nap choice because I had some in the attic. I just did the sides and front knife edges (trailer bunk contact trauma), which had green discolored and thin areas worse along the water/scum line. I masked with Scotch blue tape. I can't tell it from the pro job (Dr Bob probably could). Also did the bracket over Pettit Alumapaint, which is no longer made as this is the replacement even for pontoon boats (over epoxy base). The directions call for 'burnishing' rolled surface with 400-600 wet/dry sandpaper but I haven't got around to that yet as I would have to buy some more beer. Did it on the trailer in my driveway, 2 coats (roll a wet edge) over 2 afternoons and one six-pack Coors Light. It had ablative Pettit Ultima-60, which is hazardous and is only for professional use and $300/gal + shipping and it's heavy. So far I'm real happy, only downside is the Hydrocoat SR does not seem as yellow slime resistant as the Ultima-60, but it's way cheaper and since I can do it myself I can do it more often. I can easily remove the slime with a soft brush in 20 minutes every couple of months when beached, so it's no big deal and I had just as much with Micron CSC or Extra on the Regal in the same marina. Our marina water is now at 86 degrees, and all of our trips are very short for a Tom Cat, so your mileage may differ. Call Jamestown Distributors 800-628-8225 and ask to speak to the Pettit rep or tech with any questions, he was very helpful. Although the directions state any ablative paint must be "completely removed", the tech implied their experience is it'll stick to almost any reasonable intact surface. (Mine was only 1 season old, pro applied and intact with only the cosmetic issues). So far so good. The gallons are too heavy for a commercial shaker, so you need an empty gal paint can ($3 at Ace) and drill stirrer to mix. If (and only if) it works out in the long term, I for one will regard this as a revolutionary product...for the first time a nonhazardous water based home use bottom paint for the driveway do-it-yourselfer trailer boater. And when the time comes, remove it at your local car wash. (Don't you get any non-green ideas from me here. Your boatyard owner needs your $275 and your power washer rental in order to afford compliance with your laws).
This is the first time in 30 years of trailer boating I didn't farm this job out to the boatyard for $2200. Your original (presumed) 2-part epoxy barrier base paint might last for many years if it done correctly at the yard (by some strung-out minimum-wage 19 year old on a drug rehab work release program, but I digress).
Am I the only Brat to try Hydrocoat SR so far? If so I'll post some pictures as time goes on. For $2200 I can gas up the boat several times, so I'm real excited if this stuff works half as well as Ultima-60.
As always, I defer to Dr Bob if he dickers with me; he's got years of experience in your waters and I only rode a ferry once. 20 years ago. I probably got seasick. But we stayed at a Holiday Inn Express.
HAPPY BOATING!
John
 
Thanks for all the great responses. I'm definitely going to power wash the old paint off and take rainger's advice with the sanding.
I think the previous owner had this boat in the water most of the time. I have the boat in the water for at most 4 months and then it's dry stored for the most part. I've read that ablative paint will lose its effectiveness once taken out of the water, so I'll be looking for a hard paint.
 
Solesurfer":33y9pese said:
Thanks for all the great responses. I'm definitely going to power wash the old paint off and take rainger's advice with the sanding.
I think the previous owner had this boat in the water most of the time. I have the boat in the water for at most 4 months and then it's dry stored for the most part. I've read that ablative paint will lose its effectiveness once taken out of the water, so I'll be looking for a hard paint.
Click to expand...
Thant is why I mentioned Micron CSC it is ablative and it does not lose its effectiveness when out of the water, or so I have been told.

Look at my picture album there are a set of pictures there of before and after of the bottom. Was purchased about a month ago and the boat had been in the water for years needed a lot of bottom work,

The bottom was prepared and painted as I detailed earlier in this thread.
 
Solesurfer":2ekim0yb said:
Thanks for all the great responses. I'm definitely going to power wash the old paint off and take rainger's advice with the sanding.
I think the previous owner had this boat in the water most of the time. I have the boat in the water for at most 4 months and then it's dry stored for the most part. I've read that ablative paint will lose its effectiveness once taken out of the water, so I'll be looking for a hard paint.
Click to expand...

To the contrary. Here is a quote from International bottom paints in their tome about bottom paints: "Hard antifoulings do not retain their antifouling ability if kept out of the water, and cannot be hauled and relaunched without repainting."

It is ablative bottom paints which can be left in the water and relaunched repeatedly and still retain the anti fouling property. Not sure where you read that ablative paint will lose its effectiveness, once taken out of the water but that is not true.

In checking Micron CSC, it appears to be one of the paints banned in California. Do some studying, and ask around to find out what bottom paint is useful in S. Calif, which is not banned.
 
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