How to paint 3D printed models and how harmful is it? (PLA)

Question

3D printers

Googling says that at the beginning you should:
1. Sand the model with sandpaper and a cloth with acetone (however, it does not take PLA very well) /
2, Prime the plastic.
3. Paint with aerosol or acrylic paint, brush.
4. Varnish.
If the first point is more or less clear, then the point about priming plastic plunged me into a stupor.
Can anyone share their experience:
1. How to prime PLA, what to use?
2. What paint on acrylic is preferable?
3. What varnish is preferable?
4. Printed and painted models are planned to be used as dishes, how harmful is this?

Answer 1

1. there is a primer in the form of an aerosol, it is necessary to primer so that the paint lays down evenly, does not become translucent and does not curl. (car primer in the form of an aerosol from 150 rubles)
2 IMHO any car.
3. you can also use a simple varnish on aerosols.
4. Can not be used for food after such paint.

Answer 2

If possible, consult on painting in a car service :) We tried to paint large-sized (more than 500 mm in diameter) printed parts from PLA plastic parts on our own: it is very laborious and requires a very well-ventilated room + temperature conditions.