Sherwin - Williams strontium chromate Two part epoxy aircraft primer.
Hi Sunfish. I can't really comment on that other than to say that the paint has to be a system, it seems you are using a Sherwin-Williams system and will be fine with that.
You have used Alodine which gives you your conversion coating and adhesion so that is good.
Strontium Chromate Two Part Primer is the way I have been going myself. The problem we have in NZ is that the product is no longer available, at least not readily.
The danger is that the manufacturers are now selling a 'similar' primer. Without the chromate it is not going to provide any corrosion resistance on the 2024 or other alloys.
Magnesium is going to be the the base for a suitable new product but you really need to ensure it meets a Mil Spec or similar.
I think you have used a good system, and addressed each step in the process.
It is the guys that use a A, B, A, A system that come unstuck....
You have to use a complete and compatible system.
You can see why the LAME may not be entirely happy if someone has missed a step or used an incompatible product.
Of course the painter or owner just didn't know... they are often more than a little surprised to discover all their work is worse than worthless.
PreKote with a Strontium Chromate Primer is the method a few of us have been using in recent years. The Topcoat can then be matched to the Primer.
Super Air - Aircraft Painting
There are many different ways of painting an aircraft. They just cannot be mixed up, - what is good for one aircraft may not be suitable for another.