I'm sorry you feel that way. I did not communicate my thoughts very well. I respect the work you have done. I am doing my car with mostly my own hands as well.

I will try to explain my points better today:

IMO,
- POR-15 is an excellent product if used for what is was intended for.
- Use POR-15 on badly rusted metal
- If you use POR-15 over existing paint you have to prepare the area the same as if you were painting the panel
with regular automotive paint. So what's the point of putting a rust paint product over paint?
- POR-15 will crack, and will peel, if you don't properly prepare the surface.
- if you put the coats on too thick it will shrink and crack. Hence the paint brush.

You pic of the metal prepped. Looks good except why do you have surface rust? If you use the products ('Metal-Ready) outlined
on the website you would not have surface rust and it would have zinc phosphate coating.

We are always looking for a new "mouse trap". Nothing new here.

If you want to do a good job but not a concurs job that's fine.

Here is maybe a quicker cheaper way to do it:
Prep panel like you have done but use the cleaners and metal prep products.
Paint the rust areas with POR15.
Spray bomb the rest with top coat (any brand you want)

This is a good "refresh" solution and for some projects it's fine.

The most destructive rust comes thru from the other side. For example, if your floor is badly rusted and you only paint one side it will just rust again from the unpainted side.

The best way to do it is remove the panels in order to get access to all the metal surfaces possible (both sides). Cut out rust areas. Patch weld rusted areas. Epoxy seal and top coat.