Hello, I've bought a 2nd hand exhaust manifold which I've sent off to be electropolished, they have just rang me to inform me the manifold flange is actually chrome plated not stainless like the rest of the manifold, any ideas on how to make the flange look nice ; )
No doubt already aware of this but whatever you do to make it shiney will be undone the first time the engine is run in anger. If you want it to stay clean/not discolour due to oxide formation at high temps it needs ceramic coating
Bit of a mute point for an exhaust flange but Autosol by itself can scratch good chrome, many a classic bumper has been ruined by regular 'polishing' sessions with the stuff (or many other abrasive metal polishes). The chrome layer on decorative plating is crazy thin, the nickel layer underneath it is what provides the protection, most of the smoothness and shine while the flash coating of chrome provides the 'colour' and it's hardness protects the nickel. The yellowish/brassy tint that can appear on worn chrome is the result of polishing through the chrome layer and revealing the nickel
I'd expect someone that does electropolishing for a living to know the difference/recognise plating but on the off chance, how did they decide the flange was chromed? If it was by sticking a magnet on it 'cause it looked different to the pipework then it could be 409 stainless which is a ferritic flavour (magnetic) and makes a lot more sense than having the manifold partly chrome plated
Thanks guys, haven't got a pic to hand but here is the original http://www.spoonsportseurope.net/pr...k9/4into1-polished-race-s-s-manifold-ek9.html I did wonder how they decided it was chrome I didn't ask (I might have come across a bit patronising) but as you say they should know their stuff doing this for a living, am getting it back on Monday so I'll get some pics then.
May I ask why you are having this done? Also may I ask how much it costs?
I am used to electropolishing of cast iron exhaust manifold to reduce internal texture and so improve gas flow but I am surprised that there is much benefit to be had on a tubular manifold.
Hi David, it's purely cosmetic, as you can see the original manifold is £700+! I bought this 2nd hand for less than half that, electropolishing was £55, hoping it will look much better but we will see...