Bottom Paint Performance Question:

[magicalbill]

Don't know much about this so...

Circumstances may require me to paint the bottom of my 2018 Marlin. Situation unfolding....

If I do, what kind of performance and fuel burn hit will I take if I get the best kick-butt diamonds and gold bottom paint out there?

The boat currently is ceramic coated; current numbers with twin 350's below:

3800 RPM at 34 MPH 1.4 MPG
4000 RPM 36 MPH 1.3 MPG

Thanks!

 

[seasick]

If the hull is clean and smooth now, the paint isn't going to make a lot of different in the near term. Longer term and depending on the waters you boat in, slime or other growth may accumulate and than can add drag. In general, the longer the hull sits in the water without use, the more growth that will build uo.
The type of paint makes a difference longer term too. Hard coat paints will build up over time and will probably get rougher as it is snaded and repainted . Bottom paints are dense and heavy heavy and each coat will add more weight.
Ablative paints to an extent wear away and build up more slowly over time.

 

[ElyseM]

can't help directly, but the 330 gets 1.0 to 1.1 consistently at cruise (3800 @ 28mph) with 4 blades depending on fuel level. micron bottom paint semi ablative. not much different than the yamaha pb and i have all the factory options on it. not sure if it would be anything noticeable for you. ron

 

[magicalbill]

Seasick/Ron:

Thanks for your input, as always. If it becomes necessary to paint, I would, as mentioned, use hi-quality paint and would certainly make sure no growth occurs.

Interesting that there would be little performance difference. I have heard of 2-3 MPH getting knocked off, but that may be with paint and hull being in less than optimal condition.

 

[Bird Blaster]

tagged for interest

 

[Joez]

When I bottom painted my 226 last year with Petit Vivid, I actually noticed an overal improvement in performance. I kept it wet slipped in fresh water, and even with frequent use and wipe downs at the beach, you would still get some growth that would slow you down quite a bit by end of season. With the bottom paint, I was running the same top end at the end of the season as if I had the weekend I splashed it clean.

 

[magicalbill]

Joez:

Once you bottom painted your 226, did you have to go under and wipe it down during the course of your summer, or did the paint keep the growth from accumulating all by itself?

Good news on not losing any performance with the paint. Again, the stories i got were that it would noticeably slow you down.

As Seasick mentioned, the condition of the bottom and likely the quality of paint would help too.

Thanks for chiming in...

 

[Joez]

I researched for quite a while before settling on the Petit Vivid, one reason being that it seemed to be a smoother, harder paint than a lot of the others. It does require a barrier coat to be applied first, but that wasn't a big deal.

Yes, I would still wipe down certain areas. The vast majority would just blow off the hull when running, however the transom, the waterline on the hull sides above the chine, and at the bow, from the very front about a foot back would never see enough water running over them to self clean. But, when we hauled it out last weekend, those areas that we couldn't easily get to at the dock with the brush just wiped off with no fuss. A quick rub down and the color returned to white, no issue.

 

[ElyseM]

i think that you will definitely want to use an ablative. the micron being used is durable but does it's job. in 2017 i had the hull blasted and fully repainted (bad original job, antifoul was peeling off the primer in sheets). primer, 2 coats blue and 2 coats black. i repaint the black every year, even though its a multi-season ablative. i have the marina use their stock paint (Pacifica?) on the thruster, tabs, brackets and lowers, but i give them a bottle of cayenne pepper to dump in the paint. holds up well.

i did lose 2-3 mph top end with the switch from 3 to 4 blades, but it still fell in line with yamaha pb.

ron