[HPA Q&A] Should I use copper spray on my head gasket? | Performance Engine Building

[HPA Q&A] Should I use copper spray on my head gasket? | Performance Engine Building

– Chris has asked, I’ve seen on a few forums that people are coating head gaskets with copper spray, isn’t this a bad practice? And Mitsu’s also said particularly on metal head gaskets. OK i wouldn’t say it’s a bad practice. I have used copper spray on a MLS steel gasket and I’ve also done it without. So my preference is if we’re dealing with a proper multi layer steel gasket, I’m going to assemble that gasket dry. There is a viton coating, that’s that black coating that you’ll see on the MLS gasket and this is designed to help the gasket seal to both the head surface and the deck surface of the block. So that copper spray is not essential, it’s not necessary, and it’s not going to actually help the gasket do its job any better. Now while I don’t necessarily recommend it, I know that a lot of engine builders reuse metal head gaskets and this is where that copper spray can come in. When you reuse the metal head gasket, you’re going to find that when you disassemble it, some of that viton coating will inevitably peel off. It’s gonna end up staying stuck to the cylinder head or the engine block. And this makes it a little bit hard. Because when you reuse that gasket, you’re not gonna have the benefit of that viton coating. So my preference there is I will actually clean down the surface, I’ll remove any remaining viton coating from the gasket and then I will give it two light coats of a copper head gasket spray, head gasket sealant, and reuse it that way. Of course the best solution there is simply to use a new gasket every time. That question was take from one of our free live lessons. If you like free stuff, and you’re the type of guy who wants to expand your knowledge, click the link in the description to claim your free spot to our next live lesson. You’ll learn about performance engine building and EFI tuning, and you’ll also have the chance to ask your own questions which I’ll be answering live. Remember it’s 100% free so follow the link to claim your spot.


  1. Wonder if the comments will errupt with the spray vs no spray argument?πŸ˜‚
    Would you recommend spray if for instance you've pulled a head off and haven't decked the block or head and/or given it the correct RA finish from machining?

  2. I'd use whatever product the manufacturer recommended, if any, as they will have spent thousands of hours and dollars optimising their product for the consumer and trying to double guess is almost guaranteed to compromise their work and the seal.
    Personally, I'll be darned if I recall doing anything other than using alcohol or brake cleaner to make sure the surfaces of the head, block and gasket are spotlessly clean. Harkens back to the days when gaskets were a bit iffy and folks would use aluminium (aluminum for the US chaps) spray paint…
    For an inlet, exhaust or other gasket that was relatively lightly stressed, and would be frequently removed, it may work fine.

    As an aside, what sort of ski season are you having down there – another beautiful clear sunny day in Auckland with temp's pushing 20 degrees in sheltered places?

  3. After spending the money on professional machine work and a quality Tomei head gasket, there's no way I'm spraying mine!

  4. i’m getting my head resurfaced, with brand new gasket. i cleaned up the block and pistons with a scotch brite pad and wd 40, do you think i could spray the copper on the gasket just to be on the safe side?

  5. I have b20 vtec .I torqued down head but needed to pull it back off it has never been ran .but the nitrile coating was a lil damaged in a couple spots would copper spray fix that thanks

  6. I have a 90 mitsu eclipse 4g63t cast iron and iron head
    Now my block is warped 4 tho
    And I have done 2 commetic mls hg and a graphite felpro one and failed
    It's mixing oil and coolant one the corner where it's low warped
    Do you think it's worth ripping it apart and spraying that copper spray one the commetic on
    How think is 2 coats
    Would it fill the 4 tho warp

  7. I would never use this again, I learned it in the worst way in a big cam cummins, three months after having repaired the engine all the rubber rings that communicate the water and oil between the block and the head failed, now I have to re-do the work for that garbage, it should never be used in places where there are o-rings, I personally do not want to see more .I have talked to several mechanics that the same thing has happened to them, after a while it deteriorates everything that is rubber

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