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Refinishing MAN valve covers

Discussion in 'Engines' started by BoulderGT3, Jan 23, 2019.

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  1. BoulderGT3

    BoulderGT3 Senior Member

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    The covers on my 1550's are looking a little ragged. I like the engine room to look just right.
    I'd like to either re-chrome them, do black wrinkle or paint white.

    Has anybody done this and who did you used in the Ft lauderdale area? Thanks.
  2. Capt Ralph

    Capt Ralph Senior Member

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    There was a past (way past) thread on this.
    I think the conclusion was strip, paint or powder coat them. Nix the chrome.
  3. Beau

    Beau Senior Member

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    Coincidently, I have been researching redoing mine. I'm leaning toward a candy apple red or blue over a black base. Still researching paints appropriate for the job. Hope to do it before the summer.
  4. CSkipR

    CSkipR Member

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    I'm considering redoing mine as well as new ones are expensive. Maybe have them sand blasted and then paint.
  5. Beau

    Beau Senior Member

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    I am definitely blasting mine clean. I'm told that if I were to consider replating, the nickel content is important
  6. BoulderGT3

    BoulderGT3 Senior Member

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    I thought about this a year or two ago. I've gone back through my notes and talked to some people today in the powder coating business.
    My outboard ones are pretty pitted and bubbly. Here's what I know so far- To do plating correctly becomes dangerously close to just buying a new cover.
    The powder coating is aprox $45 each for sand blasting and coating the outside only. Any color. Hammer finish or wrinkle may work best if the covers are pretty damaged. They cook at 400°. Not sure this will warp the sealing surfaces. The gaskets should be pretty reusable, none of mine needed to be replaced after the valve adjustment. Gaskets are about $25 each if you have to replace them. The shop I'm talking to can get them turned around in 5 days.
    The tech I use is here today and I'm going to get his thoughts on the 400° causing any damage to the covers.
    Net, it's some hassle and probably $2K for a boat with 24 cylinders.
    Side note- I'm not positive but I think almost all the MAN's europe aren't chrome. Because it pits....
  7. Capt J

    Capt J Senior Member

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    On all the Euro Man boats I have managed and run, the valve covers are white. I've never seen chrome on any of them.
  8. BoulderGT3

    BoulderGT3 Senior Member

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    My tech has 20 covers (he swapped them for new on a pair of V-10) he's going to give me. That will let me try a couple of finishes. I'm going to start the process next week. We'll see how it goes and what it costs.
  9. BoulderGT3

    BoulderGT3 Senior Member

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    Still thinking about this but paint may make more sense as it takes the heat risk out of the equation. In operation, they probably don't get to more than 200° so finding a paint that will work should be pretty easy.
  10. Capt J

    Capt J Senior Member

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    I'm pretty sure the factory valve covers that come in white are just painted. Have them media blasted, throw a coat of zinc oxide primer on them, then I would use the CAT spray paint, it's reasonable, covers really well, sticks well, and easy to keep clean. It's made by Valspar, but available at any CAT dealer.
  11. Beau

    Beau Senior Member

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    Keep us posted on your results. My concern with the paint temps in not the running temps, but the "at rest" temp after a run, I'm making the assumption there is a temperature rise before a cool down - at least on the inboard side?
  12. BoulderGT3

    BoulderGT3 Senior Member

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    I don't know. I've never watched the temps in the engine room after I've been running but I don't think they go up much. I've got pretty large fans that seem to do a good job keeping the heat out. They run for 4-6 hours after I stop.
  13. Capt J

    Capt J Senior Member

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    That's not even a consideration. The temperatures on parts of the cylinder head, turbo housings and other area's are a heck of a lot higher during operation and shutdown than the valve covers themselves. Any high heat paint will do fine on them, provided you do the proper prep.
  14. CaboFly

    CaboFly Member

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    Interested to hear the results. I would like to refinish mine as well. I once saw a boat with gold covers. It was a very customized Bertram. Looked neat.
  15. BoulderGT3

    BoulderGT3 Senior Member

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    Here's the starting point. This is one of the worst ones.
    I ran into a boat that had gold ones too. They really didn't hold up.

    1.jpg
  16. captholli

    captholli Senior Member

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    I've been watching this thread with interest. Any resurfacing of these valve covers will require a completely smooth substrate so I would recommend soda blasting or hydro-blasting as these two types of blasting are the least destructive way to get down to base metal or alloy prior to a paint primer coating, plating, or hard anodizing. Chrome spray coatings have evolved greatly the last decade or so with specialized electrostatic spray equipment and chemical mixing /heating modules that select autobody and motorcycle shops have. Spray Chrome systems from Cosmichrome or P-Chrome are the big players in this arena and the cost is around 10.00 per sq. foot. This process utilizes a epoxy primer with a Black base coat than a Chrome activator and a hard clear coat to finish it off and these coatings can withstand temps up to 275 degrees and are very durable . I've had MTU aluminum valve covers hard anodized in Gold, Blue, bright Silver and even Caterpillar Yellow and the Anodizing was the most cost effective and most durable but its not a Chrome look. Anodizing can be clear coated for depth of shine but of course you have to maintain that clear coat rather than leave it and forget it. I've never had cast alloy covers powder coated but I don't think that the curing temps would pose a problem as hard anodizing temps are about the same. I will say that any of these processes are labor intensive due to the number of individual pieces involved and the repetitive steps for sanding and priming for paint or cotton flap wheel buffing with Tripoli compound to prep for anodizing or plating. The bottom line here is what the base alloy or metal surface condition looks like once the corrosion is removed as any pitting that remains after wheel and Tripoli buffing will show through anodizing or plating. Epoxy primer or enamel primer will fill in any blemishes or pitting prior to receiving a top coat so painting is more forgiving and less labor intensive. I've had valve covers so badly pitted that Tripoli and rouge wouldn't remove the surface blemishes in them so after the covers were hard anodized we picked the best looking finished products to be placed inboard and the not so perfect examples went outboard. Any of these processes aren't cheap due to the labor involved for a first rate finish but if I wanted to do it once and be done with it than it would be hard anodizing.
    Last edited: Jan 25, 2019
  17. BoulderGT3

    BoulderGT3 Senior Member

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    Captholli-

    I think this is one of those things that getting the last 10% to get to smooth perfection will cost 5x more. It’s the prep as you said. I just spent an hour with the powder coater. It looks like the chrome will pretty much flake off when blasted and there’s not much damage underneath the bubbles. Still, to make it perfect will take 3x the time. They understand not screwing up the gasket surface or getting anything inside the cover.

    I decided to do a medium texture black wrinkle. It should cover any flaws and look so much better. $50 each but that drops to $25 each if I bring in all 24 at
    once.
  18. captholli

    captholli Senior Member

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    Good deal! That's an excellent price point for the amount of pieces and labor involved. shoot us a couple of photos when done please.
  19. Capt Ralph

    Capt Ralph Senior Member

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    Now that is going to look cool. :cool::cool:
  20. BoulderGT3

    BoulderGT3 Senior Member

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    We'll see but I think so. It's got enough texture that surface doesn't have to be perfect. What would look great is to mill the top of the MAN but that probably doubles the price and leaves and exposed area to pit unless you coat on top of that.
    Geez, there's just no end to how far you could take it :).
    $25/each seems low but I look at their prep and finished product pretty closely. It looked fine. I get the two test ones back on wednesday.