School me on bottom paint

used2sail

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As I plan out my pre launch chores i am looking at bottom painting as one of the jobs I'll need to tackle this season. Last year was my first year with the boat and the marina took care of the pre season stuff but looking at the bottom last fall this spring I'm going to need to paint the bottom before launching.I've attached a photo of the boat that shows the bottom paint that was on it at purchase; this paint job now has an additional season on it. The boat is berthed in Portland Maine from April until late September or October. I know nothing about bottom painting a fiberglass hull; from what i can find on the internet it seems like a standard ablative paint is what i need. I don't know what the previous owner used and i am hoping to avoid a compatibility issue with the paint i choose to use this year whats the best way to choose the paint that i use this spring? The boat is presently in a storage yard at the marina on stands, how does one get the area under the stands painted? Can you just remove the stands one at a time and paint or is there a better way to get those areas. What other basics do i need to know, what about painting arond the sonar transducer, sea water intakes?? My lower units don't come completely out of the water when trimmed up can i paint just the forward "heel" of the lower unit to keep the fur from growing? Any other guidance on bottom paint for someone who has no experience choosing and applying it would be gratefully accepted.
 

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seasick

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Lots to digest here.
First it can be a fatal mistake to remove a boat stand without having added additional support. One common action is to paint what you can and then add an additional boat stand near to the one you need to lower to paint. Another option is to add cribbing under the hull at the chines and lower the stand a bit to shift the load to the cribbing. To do either you will need either lumber for cribbing or another stand. Maybe you can borrow a stand from a friend.

There are a lot of considerations regarding painting. Basically there are two types of bottom paint, hard and ablative. Each of those comes in different formulations such as water based or not, copper based or not and quality of the paint. Decent paint can run $200 per gallon and up.
Hard paint is what it sounds like. It forms a hard surface. Ablative on the other hand is softer and wears off as you boat. The wearing off exposes new surfaces but eventually the paint will wear away.

This is important: You can not apply hard paint over old ablative paint unless all of the old bottom paint is removed. If you don't know what kind of paint is on your hull, you can test by wiping a light colored clear rag wetted with some acetone over a small area. If the rag becomes very colored your old paint was probably ablative. An old coat of hard paint won't come off so easily.

Most bottom paint is copper based but there are options for more ecological solutions. These paints are more expensive than copper based paints. Some areas of the country are starting to mandate the more environmentally friendly options.
Bottom paints come in alkyd based formulas as well as water based offerings. I like water based because it doesn't smell as bad and your tools, brushes, rollers etc as well as your skin can be washed off with soap and water while still wettish.
Once you determine what general paint you have to use hard coat or ablative, my advice is to talk to folks who boat in the same waters and ask what they use. Different type of waters benefit from paints designed for those water and/or how you use your boat. For example, boats that are used often as opposed to boats that sit at a slip for weeks at a time often favor one paint over another.

One final warning that must not be ignored is that copper based paints should never (well almost never) be applied to metals such as aluminum as is the case for lower units. The copper in the paint can cause galvanic action that can eat up your motors:(.
There are paints designed for aluminum such as Interlux 33 ( I use a product called Alumacoat ( Pettit maybe)). FYI, may experience is that the Interlux 33 clear spray is a total wasted of money, so use a color or another product.

Most of the paint manufacturers have helpful documents and videos on the web.
For newbies there is a lot to digest

I didn't get into hull prep or primers such as barrier coats. That is a whole other conversation.
Do your research and good luck ( Bottom prep and painting is a Misérables job. At least your hull isn't on a trailer!
 

DennisG01

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I'm in similar waters to you (Friendship, ME). Easiest solution is to use something like Pettit Hydrocoat Eco or Sea Hawk's SmartSolutoin (or really any copper-free... hence the "eco"). Any of those should go over whatever you have there currently and be friendlier for the environment. Because they are copper free, you can also use them on any part of the engine, too... the heel... the lower engine bracket... etc. I do the same thing - I never even prepped the surface the of the engine/bracket - just cleaned and slapped it on.

For the hull bottom... paint everywhere you can, around the stands. Give a week to dry and then move the stands.
 

used2sail

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Thanks gentlemen, this is good information, I wouldn't remove a stand with out putting additional support in to carry the load. I'll look into what paint i can get at Hamilton or I'm sure the marina would be glad to sell me some
 

DennisG01

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Sure! The reason I mentioned Pettit and Sea Hawk, specifically, is because I know Hamilton's carries those. I've personally used both, as well. Similar performance.
 

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I have 4 stands(fwd and stern pairs) and two sets of block on the keel. The forward stands are under the level chine, not angled like yours. I use a 2x6 wood block on the top of them.
They need to be on solid level footing. I have 2'x4' - 3/4" plywood under stands and blocks. Doubled when on soil not pavement.

I crank the front up with the stands to lift off the front keel 1/8". remove the wood block. I paint what I can. Let it dry. Lower the boat back to the front keel block.

Lower the front stands and paint beneath. The boat is still held in place by rear stands and both keel blocks.(many people don't ever use fwd stands anyways.) If you are wary, move the fwd stand back enough to paint and tighten them up to the hull.

With the fwd stands in place, raise the rear stands to lift the hull off the rear keel block, remove wood block and paint.

Lower rear stands and move a bit forwrad. Paint that spot.

Stands are cranked by hand 1/4 turn at a time. It only takes a turn or two to relieve pressure.
The weigh of the boat is on the KEEL in the normal setup. When you lift the hull off the keel blocks, weight is on one set of the stands.
If you have 4x4 or two 2x4 on top of keel blocks you only have to remove pressure to get the wood out. 4" gives you space for a paint roller. No need to move cement block.
I only ever do one keel block at a time.


here is an old picture from when I was on grass
cUUC3G6h.jpg
 
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used2sail

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that picture is from Oct 2022 when i was going through the purchase process. The boat is not necessarily blocked up the same way now. Hopefully they left me a way to jockey the stands around to get the entire bottom painted.
 

Fishtales

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Another fan of ablative and Pettit Hydrocoat. Best to talk with others in the immediate area and see what they use. Some paint is better that others in extreme salt water, others in brackish. Paint what you can up to and under the stanchions. See it the marina will lift and reposition them. If not, ask if you can lift, paint the areas and let it dry before getting wet. Last alternative is don't worry about it but have the supports moved slightly each year to get better access. When I was in brackish water I could paint every 2-3 years. Not so in the hard saltwater I'm in today - every year now.
 

used2sail

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I like the sounds of the petit hydrocoat, they claim that you can apply it in the fall or winter and it will eventually dry, that works really well for me and a lot of other folks i'm sure. how much paint is required to pain the bottom of a 282 sailfish?
 

seasick

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Probably take most of two gallons. You will typically do two coats on the underside and maybe three coats on the water line edge.
If you use the Pettit, there are a couple of things to note. You have to stir the paint really well. A paint paddle in an electric drill works well. You have to stir frequently as you paint.
The second important thing to do is to not apply the paint too thick. If you use a roller, a 3/16 in nap or 1/4 at the most. You may have difficulty finding 3/16 in nap rollers in the box stores.
 

Legend

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I use Pettit Hydrocoat. It works for us in S New England so I would assume we have similar environment to tthe Portland area. I find Hydrocoat does a good job preventing excessive growth and bottom washing in the fall is very easy with a light power washer. Spring time is easier too. I find the Hydrocoat is very easy to apply with a roller and clean up is soap and water. The best part of Hydrocoat for me has been an elimination of peeling bottom paint which I assume was from a lack of heavy paint build up we saw with the older albative paint formulas
My Sailfish requires about 3/4 gallon of paint . Good luck !
 
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seasick

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I use Pettit Hydrocoat. It works for us in S New England so I would assume we have similar environment to tthe Portland area. I find Hydrocoat does a good job preventing excessive growth and bottom washing in the fall is very easy with a light power washer. Spring time is easier too. I find the Hydrocoat is very easy to apply with a roller and clean up is soap and water. The best part of Hydrocoat for me has been an elimination of peeling bottom paint which I assume was from a lack of heavy paint build up we saw with the older albative paint formulas
My Sailfish requires about 3/4 gallon of paint . Good luck !
Is that for two full coats? It takes that much for a full bottom job on my 208.
 

drbatts

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Hydrocoat user also, best bottom paint I have used. very user friendly and cleanup is easy. I use regular hydrocoat for the bottom and hydrocoat eco for the engine brackets and Lower unit. I basically do the water line, transom, and touch up every year.
 

Fishtales

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You can do a coat with a gallon. If you paint every year, this should work. If you paint every 2-3, then two coats.
 

Fishtales

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No, a gallon a coat. You'll have a little left over to touch up and hit the scum line again. I'd do two if it hasn't been done in a long while or first time (after a barrier coat).
 

seasick

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It hasn't been mentioned but it used to be a routine practice to change the color of the bottom paint from what the current color is. If you do that, you will be better able to see where the last paint has worn away over time and with use since the color that shows in those spots will be different. In my case on one of my boats, there is a layer of old hard coat that has stuck very well and over which I paint the new Hydrocoat ablative. The new paint is black and the old hard coat was blue, so it's easy to see where the ablative needs touch up.
I use to paint the hull fully each season but discovered that over time, the Hydrocoat will build up and that causes more 'flaking'. I don't know exactly why that is, but now I spot paint the underside, pre-sanding where chipping has occurred.
I lightly sand the entire water line and apply two coats using a short nap roller.