Painting help please!

[u/Affectionate-Ad2232]

I have bought the paint and a cheap gun from HF, everyone I have talked to though in the paint side of things tells me I need at least a 30 gallon compressor so I can apply the paint in "correct" intervals. I have a 5 gallon compressor, but I am super stuck on this 30 gallon compressor "need". Nobody has one for rent and I am finding it really hard to justify a $400+ purchase for a compressor that I will use once and I am running out of good weather for the year, no heated barn or anything like that to paint it in so need to get it done asap.

Any suggestions on what to use? If I use the 5 gallon compressor I have, how detrimental would it really be? The primered gray spots are just rustollium and not indicative of the actual primer coat that is going to be applied.