Painting engines

[CDB101]

My DD's were original green paint. Since I've got them out, I'd like to get fresh paint on them and then all new hoses and clamps. Going w/ white, what type of paint should I use, and any suggestions on ways to prep the old painted surfaces?

 

[Liquid Asset]

We did ours when we did the rebuilds last year. We wire brushed them and then painted them with 555 White Imron. We brushed ours because we did not have them out of the boat, but if I had them out of the boat, I would spray them with an HVLP sprayer. Just make surre you mask off all the intakes and exhaust ports so that no paint gets inside the engines.

 

[67hat34c]

Imron is the best. Good high temp and fuel resistant. However an economy paint which Dan has used and I have used is the Industrial grade Rustoleum. Home depot, Tall cans, also comes in burshable. This is a very good high temp paint. In fact i painted my onan with engine enamel but ran out and bought a can of the Industrial Rustoleum and you know the engine enamel has yellowed but the rustoleum has not. also Rustoleum has better gloss. I put paint on very heavy so it takes longer to harden.

Prep with sand blast if possible, if not then clean with degreaser first, then scrape, and wire brush, then ospho, final clean with lacquer thinner and rags, blow off with compressed air and paint it. No real need for a primer if using Rustoleum but you can. If you paint with Imron then get the dupont expxy zinc chromate primer and prime it then an hour later hit it with the imron, 3 4 coats and you are done.

 

[Boss Lady]

Just make sure to follow all safety precautions if painting with Imron, especially in an enclosed space.

 

[Brian Degulis]

Sandblasting is best but if you don't have the equiptment here's a good alternative. Seal everything up intake ex etc. Then use a high strengh caustic degreaser not the purple stuff the stronger stuff It's available at most commercial cleaning distributors. Spray it on full strengh with an pump sprayer this will break down the grease and soften the paint. Then pressure wash with a rotating 0 tip this will take off all the loose paint grease rust etc.. I recently did 2 generators in the boat this way they had lots of flaking paint and it took it right off. Imron or Awlgrip are great but your waisting money you can get the same performance from an industrial 2 part urethane like Devoe (ICI paint stores) or coronado. These paints don't flow out as well as Imron and don't hold up to UV as well. But they are 1/4 the cost have the same heat and chemical resitance and cover much better and that's what you want. Use an epoxy primer for the best job.

Brian

 

[MikeP]

do not, Do Not, DO NOT paint the wires or hoses. If you have paint on those items, get it off. It causes increased degeneration of these items and looks incredibly amateurish. Yes, many marine engine manufacturers do it because they are lazy and assemble the engines first THEN paint as opposed to the proper method for both longevity and appearance. If you are not sure how it should be done, just lift the hood on your car. You will NEVER see painted wires/hoses.

 

[Brian Degulis]

Rob B suggested tin foil to cover that pesky small stuff before painting works great!!!

Brian

 

[REBrueckner]

I have used "1500 degree" fireplace enamel on the portion of my exhaust manifolds which are not water cooled, where they come out of the exhaust ports....other wise they burn off regular paint and get rusty....it holds up well there. Does Imron turn brown from that heat there??

I have generally sprayed with white outboard engine enamel and or rustoleum which seems to work well. If you have rusty spots, prime with a sealer like Rust Arrestor" which forms a chemcial bond with the rust and turns black...no need to remove all the rust...works better if there is some rust present....All these are carried by Home Cheapo...

And as noted, never spray hoses...the drying agents in the paint also adversly affect hoses and cause premature cracking....

 

[67hat34c]

Tin foil is a great masking material, easy on and off. also you can use the plastic wrap that has a little glue on it.

 

[CDB101]

OK, so I will degrease, clean, prime and use industrial 2 part. I don't think I can borrow sandblasting equip. Should I use paint on the water cooled manifold, or should I use the fireplace enamel? THoughts?

 

[REBrueckner]

On the portion of the exhaust manifold that is water cooled, it only gets to about 170 or 180 degrees like much of the engine. It's the connections from the cylinders, with no cooling, between the cylinder exhaust ports and the exhaust manifold...a few inches... where paint can burn. After a few weeks of running Rustoleum or outboard paint turns brown from the heat and flakes off...the 1500 degree fireplace paint remains just fine....maybe a slight discoloration....I'm still waiting for a post to see if two part polys will take the heat there....perhaps 300 to 400 degrees ?? or so..just a guess.

I don't keep my engine so pristine that I really care about those small areas of brown, but a bit of rust flakes off, down onto the engine room floor and when down there crawling around in limited space of my 48 YF it invariably ends up on shoes/socks,etc...and that I do not like...

 

[drburke]

Rob,

Actually the way I will deal with it is to use brake caliper paint. You know the stuff--those little Honda tuner cars have it.

Search ebay for "G2 BRAKE CALIPER PAINT EPOXY" or "VHT BRAKE CALIPER PAINT" good up to 800-900 F.

There are special coatings for headers and stoves which are two-part, but I suspect they cost much more.

DAN

 

[67hat34c]

I painted the brake calipers on my sons Celica Red and Used the industrial Rustoleum. Hit them heavy with paint then baked in the oven.

Dont waste money on other paints. The industrial Rustoleum is all you need, Ask Dan.