Painting Marine Engines

[Rhapsody-NS27]

Originally Posted by Reefmagnet

That is a factory BetaMarine paint job in the picture

I didn't notice it was a Beta at first but was going to day that I saw the engines at the Beta display at the Annapolis sailboat show with their engines painted like that. I didn't expect to see that but still don't see how it would affect anything since it's all external. I've seen owner paint jobs here on the forum that turned out really nice, even with a pink and purple engine.

[a64pilot]

Ideally you paint an engine when it's in pieces, as in an overhaul, then assemble the pieces.
Painting the whole thing after its built is sloppy and unprofessional.
As posted earlier, you don't want to paint rubber it does shorten the life, but having said that I'm buying a 27 yr old boat that all the hoses on the engine are still covered in Yanmar grey paint, telling me they are 27 yrs old, so I guess if they weren't painted they would last, forever?

[Canibul]

lately I've been scraping paint, and the rust under it, off my 28 year old Yanmars. I think going forward I am going to just keep a can of Corrosion X next to each engine and spray them from time to time. Does a better job on the corrosion, and doesn't mask problem areas.

Now, if I can just find some better scented version of Corrosion X.

[Mycroft]

Originally Posted by a64pilot

all the hoses on the engine are still covered in Yanmar grey paint, telling me they are 27 yrs old

I don't think you can use that as an indication. Many mechanics and POs have probably cleaned up and painted using the original color to spruce it up.

[Nicholson58]

Originally Posted by ullar

Could you guys give some advice on paint and what to use to degrease before painting? For those of us that are new to that business

I would use automotive engine paint and start with a power washer or steam cleaner. I think the pros use steam. Talk to an old-timer at NAPA.

[Bayside Bert28]

POR15 is the wonderful anti rust engine paint my mechanic swears by. It's available online.

Item Detail

[sailorchic34]

For bare rusty cast iron you can use phosphoric acid to passivate the rusty iron. Worked for me anyway.

[sparau]

Thanks for all the responses

It seems my initial impressions weren't too far off, probably not the best practice but not too harmful.

[spraygun]

I have 2 Yanmars. One is the drive engine. And the other is a generator. I use high quality PPG automotive paint.I am currently repainting the genset now.here are pics.the other pics are the drive engine I did in 2009.The engine from 09 still looks like the day I painted it.both motors are done in basecoat clearcoat.

Sent from my SAMSUNG-SGH-I747 using Cruisers Sailing Forum mobile app

[ullar]

Thanks from me too. Can be a simple thing but if you don't know you don't know

[Badsanta]

Spraygun. Great job. What model is the 3 cylinder one and how did you mount two alternator s on it? More photos please! Thanks

[Roy M]

My Yanmar came fully spray painted. For me, the most important feature of the paint is that rust or oil stains stand out in contrast, so I can see things are changing on the outside. Oh, and using Hi-Temperature spray paint on the engine exhaust elbow....

[Cheechako]

Sweet job Spraygun... Question: doesnt that bottom alternator slip? not much belt contact..... heck mine had all the contact of the top one and slipped quite a bit....

[spraygun]

The 3 cyl is the 3gm20f.I made the 2 brackets from aluminum.There may not be much contact.but I found the sweet spot for tension. I did all of that in 09.I have never had to re-tighten the belt.It may not be very pretty. But it works. In retrospect I should have went with a tensioner. But it worked well enough to not need it. I chose bright vivid colors so if there was any kind of leak ,I or anyone I sent to check would see it. I also drilled and tapped both oil pans to drain the oil properly.That was the best thing I ever did. Here's a couple of pics I snapped last night of the generator. Its a lot of work in progress. I'm still having to rewire the entire thing. The last two pictures is the 3GM. One before I installed it in the boat. And the other is after it was installed.

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[endoftheroad]

Nice work spraygun,

I have alot of room under my 3gm30f, it sure would be great to have a drain in the oil pan.