Not rival methods. Points in one cycle.
A repaint and a maintenance program answer different questions. The repaint sets the clock: the manufacturer states an interval, commonly five to six years, and the finish is expected to come off and be replaced when it expires. Everything between those events is maintenance. Correct washing, periodic decontamination and a maintained coating genuinely slow the deterioration of the topcoat, because there is less abrasion per wash and less bonded contamination sitting on the surface between visits. None of that moves the interval. It changes how good the aircraft looks, and how sound the finish is, on the way to it.
Stripping is an inspection, not only a finish
This is the part that gets left out of the sales conversation. Taking the old system off puts the skin, the lap joints and the fastener lines in front of somebody's eyes for the first time in years. Filiform corrosion runs under paint as fine worm-tracks, and strip is the point at which what has been living under the film becomes visible, while it is still a surface problem rather than a structural one. FAA Advisory Circular 43-4B is explicit that corrosion inspection frequency and treatment remain the operator's responsibility, set against the manufacturer's recommendations or the operator's own program. A maintenance program, by design, keeps a film over all of it. Sold as a substitute for a repaint that is already due, it trades that look for gloss.
Correction spends a film you cannot top up
Modern aerospace finishes are basecoat and clearcoat. The clearcoat is the layer you polish, and it builds to roughly two to two and a half thousandths of an inch; the patent literature for these systems gives a one to three thousandths range. Every correction pass removes part of it permanently, and none of it comes back without a repaint. On a finish with years left, measured correction is a reasonable use of that film. On a finish at the end of its life there is often not enough left to work with, and chasing gloss finds primer. That is the technical reason a competent detailer declines work on tired paint rather than taking the money.
The failure mode: stretching the interval to save a slot
Industry practice already runs nearer seven years than the five to six the manufacturers ask for, with ten treated as the outside limit and roughly four years appropriate in coastal, salt-laden air. Stretching past that to protect an availability calendar is where the money is actually lost. A delayed repaint does not stop corrosion. It hides it, and whatever is found at strip has had those extra years to work. A scheduled paint event of five to seven weeks becomes an unscheduled repair with no date on it, and the paint job still has to be bought afterwards.
Repaint planning is partly a weight conversation
A modern basecoat and clearcoat system carries meaningfully less painted weight than an old direct-gloss finish, in the region of fifteen to twenty-five percent. That is a real gain on an airframe, and it only arrives if the old system comes off. A scuff-and-shoot leaves the old paint underneath and adds to it, so the aircraft goes out heavier than it needed to be. Composite panels complicate it further: they flex, they need specific film thicknesses, and the wrong system on a flexing part can crack or etch within a year of application. Ask any shop which approach it is taking, panel by panel.
What changes the answer
Environment first. Filiform corrosion under paint is inhibited by keeping the aircraft below seventy percent relative humidity, so a hangared Atlanta aircraft and one that lives on an open coastal ramp are not on the same schedule. Then the belly, because accumulated hydraulic fluid, fuel and exhaust soot hold corrosive material against structure however good the topsides look. Then whether a sale or a change of operator is coming, which usually decides the livery. Then how the aircraft has been washed: a finish scrubbed with whatever was on the FBO shelf has less life left in it than its age suggests. Chemistry matters more than it sounds. A cleaner qualified to AMS 1526 has been shown not to corrode aluminium, magnesium or steel alloys and not to damage acrylic glazing or painted surfaces. Boeing D6-17487 goes further: sandwich corrosion over seven days of cyclic humidity and heat, acrylic crazing, immersion corrosion, paint softening, and hydrogen embrittlement to ASTM F519, four notched cadmium-plated specimens held at forty-five percent of load for a hundred and fifty hours. A general-purpose product has never been submitted to any of it. That is one of the places our work costs more than the alternative, and it is not a place to save.