Hi Mike,
Thought that might happen with enamel on a fairly large area🤔
"Should I still use primer"
Yes! Just make sure you get the same type as the top coat you will use!
I.e. both acrylic, and preferably from the same manufacturer, to avoid any nasty wrinkly reactions ☹️😭 Paints come in 'Systems' not just types😉
Whose acrylics:
Acrylics from model suppliers, such as Tamiya, Revell, Testors etc, are very good, and you can get small spray cans, but relatively expensive. If 'price no object' 🤑 OK.
If you don't need a specific true to original colour then get yourself down to your auto accessory or DIY shop and have a look through their spray can range.
They will be much cheaper 😊 and should be fine for your project👍
I only use enamel on small projects (Plastic Magic) or fittings or when I need a specific original naval colour. Then I use the Sovereign Hobbies Colourcoats enamels, 14ml tins, (based in California) or LifeColor, 35ml bottles, from Italy, who also now do a good acrylic range but neither do aerosols (rattle cans).
So I brush the little bits and dig out the airbrush for the big bits. Do you have one?
Hope this helps🤞
Cheers, Doug 😎
Sovereign Hobbies Colourcoats-
https://www.whiteensignmodels.com/
https://www.hbhobbies.com/pages/colourcoats-sea
Lifecolor-
https://www.astromodelstore.com/brand/lifecolor