# Found a jetski manifold.  Useful?



## ericc (Oct 11, 2022)

I was riding around on my bicycle and found a Bombardier jetski or seadoo manifold sitting on the curb with a free sign on it.  I wasn't sure it was cast aluminum, but the bung welds looked like aluminum TIG beads.  This looked like it would be very useful for aluminum casting, since it would be the correct alloy, and the price was right.  The only thing that I'm worried about is the brilliant purple coating.  The manifold had a thin layer of carbon black inside it, so it must be an exhaust manifold.  That means that the coating is probably something like Cerakote.  Is this safe to break up and melt in a furnace without gassing the whole neighborhood?


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## pontiac428 (Oct 12, 2022)

If it's a polyester based coating, it shouldn't be a health hazard, but I wouldn't burn off an acrylic based polymer coating because of methyl methacrylate as a by-product.  If it's a ceramic coating, it'll come out with your flux pretty easily due to the charge present in ceramic particles.


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## rwm (Oct 12, 2022)

I'm sure it's cast. I melt painted material all the time but it does add to impurities and gas. In this case, the coating would be hard to remove and I would melt it as is.


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## ericc (Oct 12, 2022)

Thanks for the replies.  Methyl methacrylate doesn't scare me.  I work with it all the time.  I'm more worried about persistent deposits that will contaminate my furnace.  The web advertisements for cerakote says that the aluminum will melt first.  I'm glad to hear from @pontiac428 that cerakote should agglomerate.


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## pontiac428 (Oct 12, 2022)

Cerakote is so thin that it can't possibly provide enough surface tension to remain intact in any sense in the crucible.  Ceramics are tight layers of mineral clays that by definition consist of atom-thick layers of highly charged mineral particles.  It will certainly break apart and float out with flux salts.  I've never done exactly that, but it's fairly simple ion affinity chemistry.  The polymer binding agent will just burn off.   The methyl methacrylate thing is just a warning to stay upwind, which is pretty obvious no matter what.  You could always band saw off a sample piece and torch it in a ladle or crucible, flux it, and see if anything funny happens.  I'm sure that's some high quality casting aluminum under there, it would be nice for you to be able to put it to use.


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