I know it's been said already in this thread, but... modern spray paint cans. I pulled the battery out of my zero turn this morning, and of course the tray rusting. No worries, the metal is thick, just a few minutes with a wire brush and needle scaler to clean it up.
I grab a can of Rustoleum "rusty metal primer" from my bin, it was used earlier this year but properly inverted to clear the nozzle, as is my usual habit. I start spraying, and get most of the battery tray primed before it clogs hard. Clog is not in the nozzle, as always anymore, it's in the feed tube inside the can.
I let that dry, then grab an already half-used can of Rustoleum Farm and Implement "JD Green". No matter how I shake it, I can't get consistent spray unless I hold it perfectly up-right. No good, toss it.
Then I grab a new, unused can of Rustoleum Farm and Implement "John Deere Green". Not sure why one is labeled "JD Green" and the other "John Deere Green", the caps are the same color. It's clogged, right off the bat, just got a small spritz.
Then I grab a third, also unused can of Rustoleum Farm and Implement "JD Green". Second brand new can, clogged before I ever got to them. These were all bought inside the last year.
Then I grab a fourth can, some half-used off-brand (TSC?) of unknown age in JD Green, and after shooting nothing but clear solvent for a few seconds, it works well enough to shoot two full coats. I'll try for a third after lunch.
Rustoleum used to be the best name in rattle cans, when I was a kid. I always knew their "One Touch" and "2X" products were crap, but their classic stuff has always worked great. Tractor Supply used to carry Valspar's Farm and Implement line, which always worked well enough, but now they have this Rustoleum crap that just clogs right out of the box.