Etch Primer Newbie Questions

[spacebiscuit]

I have recently finished re-wiring my 71 bay window bus and fitting a new entire cab including the dash after a fire. The body work for the most part has been repaired and painted but just recently I removed the fibre-glass roof which revealed some dents which were previously hidden by the roof. These have since been repaired along with the gutters that have been cleaned. The guy who did the work painted half of the roof with etch primer which is where the project is currently.

I plan to attempt to finish the painting of the roof myself. I'm a novice but I have read up no the basics, asked questions and watched the guy who painted my bus previously.

My first questions relate to finishing the etch primer coat which is half complete.

1. Should the old (un-primed) paint work e sanded smooth with a fine sand paper before I apply the primer, if so approx which grit is reccomended?

2. Once the etch primer coat has dried and fully cured should it be sanded before apply the top coat. I plan to use a single stage (2k / 2 part?) paint which requires a hardener to be added to the mix - if I recall correctly.

I am trying to achieve an original paint finish rather than a super bright or shiny show finish. To date I have done some prepping and painting of some of my interior parts, for example:

I am soon to buy the compressor and I thought the roof section would be a good place to attempt my first paint job given that the fibre-glass roof will mostly conceal my efforts!

Here is what I am painting - albeit half of what can be seen below has already been primed as mentioned.

Any hints tips of advice very much welcome. Thanks!
_________________
1972 Type 2 1600cc
1990 MKII Golf 1.6 CL

[jason]

Etching is for bare steel. If bad areas now have etching and paint in other areas. I would sand it with the 600-800 and leave it. Spray a sealer when you paint it.