Reason for primer before shooting base?

[fltekdiver]

I'm new to spraying and only sprayed 3 tops so far on golf carts to get the feel of the gun.

However I did not prime any of the tops, first top I just shot SEM trim paint onto it lightly sanding it first and washing it down.

2nd top and 3rd tops I used TCI Super Grip adhesion Promoter waited 10 min after applying it then applied the SEM Trim Paint

This weekend I'll be shooting my first golf cart body, and see everyone recommends primer first then base

What is the reason for the primer if your using an adhesion promotor all ready to bond the paint to the body?

Also do you get a quart of primer for a body?

I'll be shooting acrylic urethane from Restoration Shop single stage Firethorn Red this weekend with a Fuji Semi Pro 2 / 2 stage turbine unit with a 1.3mm tip

If after I shoot a few body's to see if I can really do this, I'll upgrade after plenty of practice to a better unit that would atomize the paint better from a 2 stage unit

Thanks !

[MaDeucePaint]

Fltek,
So I have done my fair share of painting. Mostly custom tins on motorcycles but cars and carts here and there. Primer can serve several purposes, level out the body perfectly (high build primers), it also gives you a uniformed substrate for color to go over. Also you can tint primer to help with base coat coverage. I don’t always use primer, if (I.e.) I have a new set of fiberglass panels or plastics etc. I would scuff them, use bulldog adhesion promoter and spay my base then clear. But if you are drastically changing colors of the item it might be better to use a primer to help color coverage.