I use a "paint system" that is arguably as strong as powder coating and much easier to apply, plus requires no sand blasting.
Buy commercial Rustoleum/Krylon/ACE/Sherwin-Williams enamel in a quart or gallon can. $10/qt or $20/gal
Naphtha $8/qt or $25/gal
Alkyd Acrylic Enamel Hardener from the auto body supply shop. A pint usually runs $16
Mix 8 parts paint, 2 parts naphtha, 1 part hardener. It should be about the same consistency as whole milk. Brush or roll it on. It should be thin enough to flow evenly, but not so thin it sags/runs. I've had the best finishes by applying one very thin coat to wet the substrate, then flow over a wet coat about 10min later when the first coat flashes/tacks up.
You can also use a $16 Harbor Freight sprayer to apply it.
If you have bare or rusty metal, use POR-15 primer. If it's previously painted, hit it with 250-grit sandpaper or a 3M pad.
The addition of the hardener catalyzes the paint, and makes it dry about 5x as fast as paint alone, plus it makes the finish much harder and as scratch-resistant as powder coating. It's also a million times easier to touch up than powder coating. The naphtha helps thin the paint so it flows better and smooths out; it also helps the paint dry faster.