Magnesium Valve Cover REFINISHING
 

I am surprised there's not more info on this, so here goes.

I am refinishing an m104 Magnesium alloy valve cover. I had it media blasted and the end result was porous. I then had it vapor honed and it brought out the nice bare shiny magnesium silver. My intention was to then have it powder coated. But it was suggested to just put a ceramic coat on it with cerakote and call it a day. I don't mind this idea, as it looks quite nice... but I am skeptical this will hold up. If there is no coating on Magnesium, it will just fall apart.

Also on the inside portion of the valve cover, the old coating is starting to flake off. I have heard "don't ever strip magnesium, it will damage it." I have also heard not to media blast the inside because you don't want it to become porous. I have also heard, the flaking is not a big deal, just leave it, there are filters that will catch it.

Does anyone have any opinion here?

Is a ceramic coat enough to protect bare magnesium? If I powder coat it, I know there are many shops that won't touch magnesium... and you have to be careful how you bake it.

What should be done about the flaking coating on the inside of the valve cover?

Thanks in advance! See pictures below.

Eric

Painted mine with red high heat paint, been on 10 years. Insides be careful don't want bits in your engine, maybe clean it and leave it be. Oh yeah painted spark plug valley, left clean where coils ground, coils stay cooler, and last

Magnesium forms an oxide layer, similar but stronger, to aluminum metal. It creates a dull, white layer. This protects the metal from further decay. The reason steel rusting is so severe is that iron oxide expands to around 10x its original size and flakes off. The oxides of aluminum and magnesium stick tightly to the metal, and form a protective layer that pervents further rusting.

W/O a coating, magnesium parts will be okay. Now, if you want to keep it shiny, then a coating will be necessary. Unfortunately, I have no experience in painting magnesium parts, so I cannot suggest a best course.