Then paint with a metal primer and a finish coat.

A smooth, white finish coat goes on last.

Make sure the sealer (sometimes called a surface conditioner) will be compatible with the finish coat.

Apply an undercoat or sealer first, then a finish coat.

The finish coat usually contained an integral color and was typically textured for appearance.

The finish coat should be the last work of the day, when no more dust was being raised, and when the wind died down.

And after that, there are two or three more finish coats.

Others are finicky about the finish coat of paint.

The finish coats may also help seal the surface, reducing the adverse effects of humidity or sunlight.

Also, I strongly recommend a first coat of exterior primer before any finish coats are applied.