Question on primer

[Railroadman]

The utility box on my '66 project has 2 or 3 coats of paint, and will need body work as well. I'm thinking it will make a nice winter project to strip and prime it, and do spot work here and there.

I admit I know little about paint, and what little I DO know is probably about 30 years out of date. For some small parts I was working on a while back, the local paint supply store sold me a rattle can of self-etching primer and it seems to work well. It's Dominion Sure Seal if that helps.

I have heard that some primers attract and retain moisture. How much risk or harm would I be doing to strip, clean and prime the utility box itself with that same primer? The truck, when finished, will be for cruising and occasional light work like firewood, not a showpiece for judging.

Thanks!