How many pads? Consider how many of those little yellow foam pads you normally use when applying polishes by hand. The PC's pads will last a bit longer before needing cleaning, but the principle's the same: don't use any one pad so long that it's caked up or clogged with chemicals such that you're putting scratches back into the paint.
Background: 1996 Miata M-edition. Used the PC7424 on only two cars so far. Mine will be soon. All my prior experience has been via hand polishing; plus the PC on a black 1984 Mustang single stage and a red 1993 Miata clearcoat, recently.
I've got the following (though, some will think this overkill). Works very well when doing a car with two people, with one focused on the DA polisher, and one focused on cleaning up the residues from the car and the pads.
Pad selection depends on the defects you're trying to correct. My arsenal includes:
* 2 yellow/orange pads -- for bad swirls and oxidation
* 4 white pads -- for mild swirls and hazing
* 4 black pads -- for mild polishing/glazing
* 2 blue pads -- for finishing
plus
* 2-3 dozen microfiber cloths, to clean up residues
* 3-4 microfiber final buffing cloths, for buffing the final coat
Tip: the Lake Country curved-edge variable-contact pads are far superior, IMO, to the straight variable-contact pads. Far simpler to modulate heat/pressure, and they seem to last longer and dramatically postpone the frayed condition lesser pads get.
On a car that's not bad at all, the yellow/orange pads are used for localized problems. These pads will put a bit of hazing across the panel you're doing, which will then need to be worked out as you step down the intensity in pads/chemicals.
The white pads take the brunt of the polishing action. You can vary the strength of the chemical accordingly and get a little more or less work from the same pad.
The black pads are for fine polishing, as they're fairly soft. I've used them for final polishing, glaze.
Got the blue Lake Country curved VC pads on order. These will be strictly for the final finish coat with zero polishing.
For me, the following sequence seems to work best. When a pad has begun to get clogged, it can be flipped into a soapy bucket of water, rinsed out 30mins later, then left to dry. After two cars' worth of experience (not much, but enough to know this), it's clear that one pad begins clogging after a hood + one panel, more or less. Any more, and that pad starts putting in scratches and has reached wash time. One person can focus on the polishing, while the other cleans up residues off the car and keeps the pads clean and ready to use. With enough pads in the pipeline, then a single car can be done by two people straight through, without worrying about using dirty pads.
By comparison, I did an entire black 1984 Mustang (non-clearcoat) with just a few pads. After a couple days of work on the car, they were toast. They would be in much better shape if I had cycled them more frequently. At the end, two of the white pads had no more polishing ability in them; they simply could shove the polish around and cause scratches. Tossed them at that point.
So. How many pads? Depends on how rough the paint and how long you'll need to go over surfaces. Think about it, first. Gauge how damaged and what grit of pad to use. Imagine the couple of chemicals you'll use on that pad (ie, white pad, with Meguiar's Dual-Action Cleaner Polish, then Meguiar's #9 Swirl Remover). Gauge how many steps you'll need in the process in order to get the damage out (ie, orange with DACP, white DACP, white with #9, black with a fine polish, black with a glaze).
YMMV.
Good tips here:
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