Engine Room Paint

Another "vote" for Interlux Bilgecoat. I found it very durable.
I have also used gelcoat and prefer the bilgecoat paint.

The problem with gelcoat is as it gets dirty and oily as it ages, even when you are trying to keep it clean, it will never clean up totally. And so it will start to look dirty with age.

Capt.Bill11 said:

The problem with gelcoat is as it gets dirty and oily as it ages, even when you are trying to keep it clean, it will never clean up totally. And so it will start to look dirty with age.

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If it gets that bad, lightly sand, acetone, and 2 more coats. One of the big pluses over paint is that it's easy to recoat. No issues with pealing and compatability problems as long as you prep correctly.

Ted

Thanks all for the input. So many good options. For this boat, I think I need to consider the bilge and engine room as two separate areas. The bilge is separated from the engine room with a fiberglass liner. The bottom of the bilge is deeply recessed into the keel from the forward cabin to the aft cabin. There is nowhere in the boat where I can touch the bottom of the bilge. It is 2 or more feet from the bottom of the oil pan. The engine room liner is like any other fiberglass component popped from a mold; smooth and shiny.

Capt. Bill suggested using a tried and true product like a two part poly Awlgrip. I absolutely agree. I plan on using some leftover color matched Interlux Perfection on the ER liner floor and walls. After years of having tools and other stuff drug over it, it needs a good hard paint.

I was drawn to the Rustoleum 5300 for the bilge area because it is billed to be designed for moderate to extreme industrial environments, is low VOC water based with thinning and cleanup with water. No extra thinners or noxious solvents needed. And it can be applied with an airless paint sprayer. With the small spray head of my airless sprayer, I can get paint into all those impossible to reach places.

Early in this thread, joesubmariner had concerns about paints failing and peeling due to engine room heat and contaminants. This stuff claims 300 degree dry heat resistance.

So??? I was hoping someone had tried it and had some firsthand knowledge. Since the re-power is three to four months away, I'm going to try a test spot in an area subject to water, oil and heat, and see how it holds up.

Thanks to all!

Bob

O C Diver said:

If it gets that bad, lightly sand, acetone, and 2 more coats. One of the big pluses over paint is that it's easy to recoat. No issues with pealing and compatability problems as long as you prep correctly.

Ted

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But once stuff is back in the engine space you can't get to all the areas that need to be recoated. Gelcoat is cheap and easy I guess. But nothing beats a nice smooth and clean two part poly coated engine space.

Super bright, easy to clean, very long lasting and almost nothing attacks the finish.

Capt.Bill11 said:

...Gelcoat is cheap and easy I guess. But nothing beats a nice smooth and clean two part poly coated engine space.

Super bright, easy to clean, very long lasting and almost nothing attacks the finish.

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A downside of using a 2 part polyurethane paint in the engine space is it has to stay dry with no standing water so it is not a good choice for bilge areas. The paint will blister and peel if in constant contact with water.

Is this recommened for fiberglass?

This is for steel and can be used on masonry, but unless I missed something, it didn't say it was recommended for fiberglass did it?

remwines said:

Hi All. I will be doing a re-power on my boat this Spring. We will be cutting a big chunk of the Salon floor out to swap the engines. After that, I will spend a good deal of time on ER cleaning, painting, sound proofing and upgrading before the new engine is dropped in. After reading this thread, I started to check out the different paints everyone was using for the bilge and ER. I didn't see that anyone had used the Rustoleum 5300 Water Based Epoxy System and thought I would throw that one out there.

This is a two part system, 1 gallon of base and a pint of activator, that is fairly low VOC and can be applied over a slightly damp surface (mine will be dry). They claim it will stick to nearly everything including ferrous and non-ferrous metals and can be force cured up to 225 degrees. I don't plan on getting the ER that hot, but I can get well above 100 to get it set. It can be thinned with water and cleanup is with water. Here's the Technical Data sheet:

http://www.rustoleum.com/tds/5300 System_RO-52_2027990.pdf

Tell me what you think. Price isn't real bad. Gallon of paint and pint of activator is $75 on eBay/Zoro with free shipping.

Thanks.

Bob

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I just finished my engines with Rusoleum high temp, the bilge and decking with gray Rustoleum gloss oil based enamel. On a prior bilge, I used Interlux Bilgecoat and switched to Rusoleum mid job due to the cost. I liked the Rustoleum enough to use it again. I am also painting a 25' Chawk with Rustoleum Topside paint and Bottom paint. I am impressed and will not hesitate to recommend any Rusoleum marine products.

AV8

Larry M said:

A downside of using a 2 part polyurethane paint in the engine space is it has to stay dry with no standing water so it is not a good choice for bilge areas. The paint will blister and peel if in constant contact with water.

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No it doesn't. If the surface is prepped correctly.

Larry M said:

A downside of using a 2 part polyurethane paint in the engine space is it has to stay dry with no standing water so it is not a good choice for bilge areas. The paint will blister and peel if in constant contact with water.

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Capt.Bill11 said:

No it doesn't. If the surface is prepped correctly.

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Prep has nothing to do with it. It's the nature of 2 part polyurethane paints. They are not made for constant immersion in water. Boat hulls painted with a 2 part with water lines that are too low can have issues. Decks painted with a 2 part that have carpet, if the carpet doesn't dry out will blister.

An epoxy, gelcoat or a designed paint would be my first choice.

Cuttyhunk47 said:

This is for steel and can be used on masonry, but unless I missed something, it didn't say it was recommended for fiberglass did it?

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Cuttyhunk47: you're right, I didn't find anything in the Tech Sheet that said it was recommended for fiberglass. But the Product Application section on the sheet reads, "PREVIOUSLY COATED: Previously coated surfaces must be sound and in good condition. Smooth, hard, or glossy finishes should be scarified by sanding to create a surface profile. The High Performance Industrial Water Based Epoxy Finish is compatible with most coatings, but a test patch is suggested." Everything I planned to use this on is already a painted surface. It's all in good shape, but needs a thorough degreasing and sanded for tooth where I can reach. I am going to do a test patch near the engine and next to the bilge water line for a few months to see how it holds up.

Thanks.

Bob

I've not had problems with good 2 part polyurethanes immersed in water full time. Never even thought about it being a problem. Its about the most waterproof of any paint, especially over an epoxy primer. Now I'm gonna have to worry about all that paint thats now underwater, dangit

Larry M said:

Prep has nothing to do with it. It's the nature of 2 part polyurethane paints. They are not made for constant immersion in water. Boat hulls painted with a 2 part with water lines that are too low can have issues. Decks painted with a 2 part that have carpet, if the carpet doesn't dry out will blister.

An epoxy, gelcoat or a designed paint would be my first choice.

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What can I say. I seen/had bilges painted with 2 part polys and not seen any lifting.

But if its a concern, just paint down to say 6" of where any standing water might be and then paint from there down with something else.

Preferably, IMO, with almost anything but gelcoat.

Capt.Bill11 said:

But if its a concern, just paint down to say 6" of where any standing water might be and then paint from there down with something else.

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That's how the inner hull on this boat was painted before assembly. It has a foot deep recess into the keel that is about 4" wide. So water, oil, wrenches drains/falls into this crevasse. It is good the builder only painted down to the trench and left the rest bare fiberglass. I won't be painting down there, even with epoxy.

Larry,
We have Awlgrip. Our stern sits lower in the water then when the yard painted it. Our Awlgrip has blistered and flaked off at the waterline above the bottom paint.

As most proper laminates are fairly clear , there is thought that NO paint be used below the cabin sole so grounding or structural failure can easily be seen.