10-09-2020, 12:08 PM
Interesting that the exposed material is brown in colour.
Nevertheless, isn't the cylinder head cast aluminum? If you take a small metal file, can you remove the brown material to expose new aluminum? I realize new aluminum will oxidize immediately when exposed to air, however, it should settle down to a grey or whitish-grey finish - which should stop oxidizing. I do not know if further reactions occurs due to exposure to a salt-water environment. Is that the reason it is called "rot"?
In terms of high heat paint, silver-grey spray can high-heat paint has been readily available for decades with some tolerating the 1400F temperature range. That should be more than enough margin.
Nevertheless, isn't the cylinder head cast aluminum? If you take a small metal file, can you remove the brown material to expose new aluminum? I realize new aluminum will oxidize immediately when exposed to air, however, it should settle down to a grey or whitish-grey finish - which should stop oxidizing. I do not know if further reactions occurs due to exposure to a salt-water environment. Is that the reason it is called "rot"?
In terms of high heat paint, silver-grey spray can high-heat paint has been readily available for decades with some tolerating the 1400F temperature range. That should be more than enough margin.