The crank/brakes where painted, but one has to know the right base coat (i forgot what the painter used).

When i told him about the former painter how he screwed up he smiled and explained me about the preps one has to do and not just paint alu without for example blast the anodised layer of.

I also considered anodising, but i did not get the right answers and turned to my ever faithful painter who i trust completely as he has done several non everyday jobs and he knows his stuff.

Further is it that i like the contrast of what paint can bring as an extra.
There for i did what i did regarding the black paint on the alu parts.

Thanks everybody for your kind and encouraging words