Machine versus hand: what each tool can and cannot do
The workhorse of modern polishing is the dual-action (DA) machine. Its head spins and oscillates at once, which spreads heat and makes it very hard to burn through paint — the tool most mobile technicians should be running for most jobs. The rotary polisher, spinning on a single fixed axis, cuts much faster and suits heavy correction in experienced hands, but it concentrates heat, bites at edges and creases, and causes most of the horror stories in this trade.
The machine is only a third of the system. Pads range from aggressive microfibre and firm foam cutting pads down to soft finishing foam, and compounds run the same spectrum from heavy cut to ultra-fine finishing polish. A skilled operator matches pad, compound, machine speed and arm pressure to your specific clear coat — Japanese paints tend to be soft and mark easily, many German paints are hard and need more cut. That matching is the actual craft you are paying for.