After the chips are feathered out using a DA sander a good two part Primer Surfacer is used. Areas that need to be filled can be built up with this. 

The Primer  Surfacer is guide wet sanded with 320-400 grit. Use plenty of water in a rag or from a hose set to trickle water to wash away the material.. You can "speckle" some black guide coat over the  primer and when sanding the low spots remain black and you can continue to sand them till they a gone.

Cowling has been wet sanded and needs to be cleaned using soap and water

If you are masking off some of the old stripes that will remain, use a Fine Line tape to establish the edges.

Mask off the remaining area that will not be painted

A good primer sealer will be shot over the area to be painted. This will provide a good surface over the entire area to prevent the new paint from penetrating the old paint and causing any lifting of bubbling. This product is Jet seal and R4K179 reducer which will be mixed 50/50

Clean the surface with a wax and grease remover

Clean surface with a tack cloth

Get color paint mixed and catalyzed

Primer sealer coat shot over the surface to be repainted.

Color coat painted