I'm not an expert but I have refinished and painted stuff (cars, boats - not airplanes)
I would approach this one of two ways. One- DIY Scuff and spray. Hand sand with very light sandpaper just enough to scuff the existing paint, clean to remove all wax (use aluminum safe cleaner) and shoot it with a two part, single stage high gloss automotive enamel. Of course you will need to find an A&P to check the control surface balance before flying.
Two, pay someone for a full on professional job.
I've painted a Vans aluminum homebuilt, composite glider wings and various patch and repair jobs. I'm a total amateur.
Scuff and spray seems reasonable, but.
Rivets for a start; you will hit bare aluminum on the tops and you will have a hard time scuffing around them.
A question to ask is, "why are you painting?" Peeling paint? You'll need to remove that and deal with bare aluminum in those spots. Surface (filiform) corrosion? That will continue unabated by repainting unless stripped and (see bare aluminum). Faded paint? Compound to work off calories and fly, or just leave it - it's an airplane, fly it. A quick/cheap job can only make fly worse and look bad later.
Automotive urethane is what I used, two part single stage in particular. The good stuff is good stuff... and expensive but that's a nit relative to the overall effort. A lot of the aviation product is made to withstand 400 knot rain - hyper expensive and good if you can find a distributor.
Random thoughts; I'll just paint it white, no striping. You've already done the heavy lifting, a bit of trim is a real price performer no matter how you do it.
Latex house paints... fine for homebuilt sport aircraft that are trailered, stored indoors, fly 80 knots in sunny wx. One trip at 120 knots and rain and degradation starts...
The best $$$ saving approach is DIY, but. I concluded there are not multiple tiers of aircraft paint shops.... just experienced and competent, and those that may become so, or not.
ps: Total compliance with environmental regulations is demanding and costly and critical for a pro shop. You can and probably should evade or counter some of them on a DIY job, e.g. VOC regs dictate that Urethanes (the very good, easy to get a great job with stuff) are thick and to be used with little or no thinning. Thin the stuff a bit beyond the reg limiting specs and suddenly you can do a good job with cheap equipment. The stuff is toxic as hell so be sure to protect yourself with fresh air breathing equipment and don't overspray your neighbors car or plane. But you aren't running a shop doing multiple jobs a year with multiple employees who WILL suffer from the toxicity eventually, along with the general public.
Then go watch a boat shop with a 50' paint booth paint a 75' yacht hull so you can feel good about yourself.... no, actually run the other direction.
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