Hi everyone, the Valve Covers on out Dino GTS sadly were polished. Does someone knows, how to restore the "out of mould" finish? Would be very happy! Thanks
The best thing in my experience to replicate the effect of an original aluminum casting is to use fine glass bead (NOT crushed glass) in a blasting cabinet. Walnut shells might work also but I have no experience with these. Just don't use harsher blasting media that more aggressively cut the surface as they don't give the right look. Start at a low pressure (say around 25-28psi) and see if you are satisfied. If you want a slightly rougher finish, gradually increase the pressure. You will get a smooth, even, semi-dull finish. After some time passes the surface of the aluminum will naturally corrode and get a bit duller, leaving you with a very authentic look. Best Regards, Paul
Mine were nasty so I aluminium oxide blasted then glass bead blast but I blast at the 100 psi + and they come up original.
Where are you located? Perhaps, fill out your profile I used a shop in the US which has a huge glass bead tumbler and that provides a very uniform finish with nice luster resulting
My Euro Dino has magnesium valve covers which had that dark oxidation on them. I blasted them with medium grit and the photo shows one just finished next to one before to show the contrast Image Unavailable, Please Login Image Unavailable, Please Login
That dark finish was not oxidation but Dow 7 Dichromate coating that was added to the covers during manufacture to protect them from oxidation. By removing the coating they will corrode.
Any internal part of the engine in contact with oil should not be glass beaded as the glass beads can become imbedded into the surface material, and dislodge under operating temperatures. The dislodged particles can cause damage to any bearing or machined surface, and premature engine wear/damage. If parts are glass beaded, then aggressive cleaning in hot soapy water must be done (solvents will not remove the particles), or internally sealed with paint such as Glyptal Red which is designed for these conditions.
Great advice, thank you. Masked off and no direct contact with interior. Dow was long gone on these, this was oxidation, evidenced through pitting and multiple prior blasting wear on "Dino" raised letters.
If the covers are from an E series then they are presumably aluminium not magnesium so would not have had the Dow coating when new.
