[DeTomaso] Alum. Polishing advice needed

[Brent Stewart]

Perhaps I've gotten in over my head.  I fancy myself reasonably adept at polishing the odd aluminum bit, shift gate, valve cover, etc. and getting a very nice shine out of it. So, i figured the back end of my CHI aluminum heads should be no big deal - not a lot of surface area, so it should be pretty easy.  

I got myself a little buffing wheel for on the end of the drill, and a new "Power Cone" from Mothers, and some 320, 400, and 600 grit paper. Following the process you might expect, i got it down to looking and feeling very smooth with the 600 paper, then hooked up my buffing wheel with a little Mothers Metal polish and went to work on what i thought would be the final phase. 

Fast forward 2 hrs, and i'm still looking at a very dull, gun metal gray finish that i can't for the life of me get a shine out of. 

Has anyone else ran into this unexpected bump?  any suggestions or ideas would be helpful!!

brent