You can now buy 2K primer (even 2K epoxy primer) in a spray can. It has a special activating button that mixes it, and once mixed is good for about 24 hours. It costs big bucks--about $20 for a can. But if you need to do a relatively small panel, or small parts, and want real primer coverage in 2K form (which is really what is needed for a proper base), it sure is handy. There are a couple brands out there, but the one I've used successfully is called SprayMax. If you google it you will be able to shop comparatively.
The House of Kolor epoxy I use is right about $40 per quart, or $80 for the two quart kit. (part a and part b) So if you're on a budget, the epoxy in a spray can, given the 24 hour usage window, may not be as cost effective as mixing your own and mixing only what you need, versus wasting part of a spray can to the product curing. But if you don't have the spray equipment needed, the 2K or epoxy in the spray can IMO will give a much better substrate for your paint job than any single component spray can...
