Is it best to prime already painted parts or can i just spray over the top?

Like a wing mirror housing.

Depending on the colour as that will effect the finished look, but generally you should be able to flat it back and then repaint.

I was thinking of taking it from white to gloss black.

So if I'm reading it right, i'd need to sand the white to take off the gloss and then spray?

Yeah just get it back to a flat dull even colour, then paint.

As above - doesn't need to come right off. Just back to a surface the primer will adhere to. Really, its the lacquer which needs removing rather than the basecoat.

Cool

Thank you both.

Once its all nice and shiney after the black has gone on, how many more layers of black would you do? Then how many of the lacquer?

I've done stuff in the past but its well in the past.

Yep, give it a rub down to let the paint stick, a "key", then primer, and then the colour

Lots of light coats work the best, you could give it some laquer (although with a solid, this isn't always neccesary), don't forget to polish it with a rubbing compound, like Auto Glym's paint renovator.

I notice you're in Bedfordshire, if you're local to me I could show you how do it if you got stuck

Edited 6 January, 201115 yr by RiceNik

Yep, give it a rub down to let the paint stick, a "key", then primer, and then the colour

Lots of light coats work the best, you could give it some laquer (although with a solid, this isn't always neccesary), don't forget to polish it with a rubbing compound, like Auto Glym's paint renovator.

I notice you're in Bedfordshire, if you're local to me I could show you how do it if you got stuck

Thanks for the advice and a big thank you for the offer of a hand, its appreciated.

As mentioned previously, a light rub down using 1500-2000 grit wet 'n' dry paper then a couple of coats of grey primer followed by 2 /3 of Black, if the final colour isn't metallic you don't have to use lacquer, that is normally applied to stop the metal flakes in metallic paint rusting. Ideally to finish a machine polishing with a cutting polish but it can be done by hand with a bit of elbow grease.

This is pretty much the method I used on my parking sensors, swmbo thought I'd lost the plot when she found me with the DA polisher on them!

i'm itching to press the 'on' switch on my new shiney DA.

one case has been rubbed down with wet/dry, just need to get the other one done now.