How does a dual-action polisher move?
Its pad does two things at once: it orbits around an offset centre and it rotates. The pad’s path over the paint keeps changing, where a rotary buffer simply spins in one place.
Makita’s PO5000C feature sheet shows the numbers on one such machine: a 5.5 mm (7/32 in.) orbit, up to 6,800 orbits per minute, and a choice of two modes. Its instruction manual explains them:
| Mode | How the pad moves | Makita’s intended use |
|---|---|---|
| Random orbit with forced rotation | Orbits while the motor drives the spin | Rough polishing, such as surface treatment |
| Random orbit, free rotation | Orbits while the pad turns freely | Fine polishing |
Why do carmakers reach for a DA before a rotary?
Because it’s the less aggressive machine, and Chrysler tells technicians to always begin with the least aggressive method. Chrysler’s bulletin 31-001-13 has technicians try clay first, then a D.A. polisher with a foam finishing pad, and only then a rotary buffer, a machine Chrysler limits to trained technicians because in the wrong hands it can permanently damage paint.
GM’s PIT5763 gives the DA the last word on a repair: after the sanding and polishing, a dual action orbital machine on a foam pad takes out whatever swirls are left. That finishing role is why a DA is the usual answer to holograms left by heavier work.
What a DA can and can’t do for your car’s paint
It can remove wash swirl marks and the fine marks heavier polishing leaves, and carmakers rank it below the rotary for risk. It can’t avoid removing clear coat, because the polish under the pad is still an abrasive.
That’s why the machine matters less than the reading taken before it touches the car. On paint that has been polished or repainted before, the thickness gauge decides how far even a DA can go.
Where you’ll see a DA at Brookswood Tint
On the shop’s correction and coating work. The photo on this page was taken there, during correction on a black Chevrolet, with swirls still visible in the fender’s reflection.
Paint thickness is read before any machine goes on, and the level is chosen to match. The lightest is the one-step paint correction, about a day; the full ladder of levels is on paint correction, and the process is explained in what is paint correction?