'High-Temp' Paint Req'd for Manifold?

[Moor'ea]

Hello all,

First off, I'd like to start by thanking Mr. & Mrs. Moyer, as well as all the other Atomic 4 addicts floating around this forum. Earlier this summer, I took over ownership of my father's Ericson 29. While the boat is in OK shape, the Atomic 4 was in a slightly sadder state of affairs. Indeed, I had a trifecta: No spark, No compression, and No Fuel. With the help of the wonderful Overhaul and Service manual, I tore down the top end of the engine and discovered that ALL FOUR exaust valves were stuck, and the number four (farthest from flywheel) intake valve was also sticky. To top it off, there was a pool of rusty water in the number four cylinder, and quite a bit of rust around the number four valves. A lot of love, a lot of MMO & PB Blaster (that stuff is amazing), and a lot of blood, sweat and cursing, I managed to coerse all the valves out of thier homes, installed new valve springs, lapped the valve seats and replaced the valves and they are all now moving up and down fantastically! Also rebuilt the water pump, and the Carb was full of gunk, but a can or two of aerosol carb cleaner and a late model carb rebuild kit later and it seems fine.

Anyhow, on to my original question... (sorry for rambling a bit, but after 10 years or so of this engine not running, it's very, very exciting to be this close to firing her up again!) OK the question...Before I put everything back together, I want to paint the engine so that I can ward off any more rust and I was wondering if the "High Temp" paint listed in the exhaust section of the online store is necessary, or will the "Universal Bronze" paint be fine? It seems like the pictures of freshly rebuilt and painted engines on the home page of moyermarine.com are painted entirely with the "Universal Bronze" paint.

Thanks in advance for your response!

[Don Moyer]

For castings that can be professionally cleaned down to bare metal, the manufacturer of our Atomic 4 bronze recommends Rustoleum primer "for rusty metal". For painting surfaces that are not easy to clean (leaving some rust behind), there are some higher tech primers that are available which others will hopefully check in to recommend.

I know that a few of our customers have been using our high-temp exhaust paint on manifolds, but unfortunately we have no reports as of this time as to how it works as a primer or undercoating for other paint. Our vendor isn't able to give us any experienced based information on the subject either. If you're willing to give it a try, send me your shipping address, and I'll ask our warehouse to send you a free can so you can test it on your manifold (or anywhere else for that matter) and only ask that you get back to us with the results.

Don

[Moor'ea]

Don, I'd love to perform this experiment for you.

My shipping address is
Jay Hickman
295 Harbor Drive
Sausalito, CA 94965

Thanks again!

[Don Moyer]

Thanks Jay. We'll get a can of our High-Temp paint on the way. Unfortunately, due to postal codes we'll have to ship it via ground transportation. It should be there in about a week.

Don

[Moor'ea]

Okay, great!

I'll keep an eye out for it, and let you know how it works out.

Jay

[HOTFLASH]

Outcome of Hi-Temp paint test for manifold

Did it work?

[rigspelt]

I am still not clear after searching here and elsewhere: is 500 degree engine paint OK for the manifold and head, or do those parts need 1200 degree paint?

[High Hopes]

Someone informed me, I think a paint rep (or the paint label?), that the exhaust paint doesn't really cure hard until it hits 350 degrees.

[StephenGwyn]

I've heard on this forum, and on the phone with Ken, that one should use Rustoleum rusty metal primer. But reading the side of the can it says it shouldn't be used on surfaces that get hotter than 200F, The manifold definitely get's a bit hotter than that, as do parts of the head.

However theory is one thing and experiment is another. What were the results? What are other peoples' experience with low temperature paint?

SG

[BunnyPlanet169]

In my limited experience, the rusty metal primer and MMI A4 'rusty bronze' paint will hold up to normal and modest abnormal temperature. That's anything external to the engine, and also includes the block and head. Everything except parts of the exhaust manifold which has uneven cooling. There is even a forum name for this: the UHS or Ubiquitous Hot Spot, typically on the lower corner of each end of the manifold where the paint will begin to scorch. I'm not sure that it doesn't do the same around the spark plug wells, but they tend to collect enough dirt that I can't tell the difference.

I have painted my manifold with a hot exhaust silver, but I won't know how it survives till I bake it on this spring. The application notes were to apply to unpainted surfaces, and then not to re-coat after drying until after a full temp baking cycle.