GENERAL SPECIFICATIONS

Porter Cable dual action random orbital buffer / polisher / sander
2500-6000 opm (orbits per minute)
3.7 amps, AC motor
5/16", 24 thread shaft / spindle diameter (aka "5/16-24")
5/32" eccentric offset (orbit radius)

5.75 lbs weight
10" length (body)
<14" size of box needed incl. cord sheath
4" width
4.5" height
+5.5" with side handle

Model 7424 polisher includes 5 inch counterweight, 6 inch polishing pad 54745 *
Model 7424SP sander/polisher includes 5 inch counterweight, 6 inch polishing pad 54745, 5 inch sanding pad 13700, Meguiar's cleaner wax
Model 7335 sander includes 5 inch counterweight, 5 inch sanding pad 13700

Model 7336 sander includes 6 inch counterweight, 6 inch sanding pad 16000
Model 7336SP sander/polisher includes 6 inch counterweight, 6 inch sanding pad 16000, 6 inch polishing pad 54745, possibly wax also

Models 97355 and 97366 are just the 7335 and 7336 with dust collection parts



BACKING PADS & COUNTERWEIGHTS

Meguiar's W-64DA backing pad is 5" diameter
Classic Motoring Accessories (CMA) VBP-6 backing pad is 6" diameter
Griot's Garage backing pad for their 7336 is actually Porter Cable 18001 6" sanding pad (Thanks to Len_A for this info)
3m Hookit pads - all these pads are yellow and NOT to be confused with Hookit II:
Hookit Disc Pad 05775 is 5" (tapered edge)
Hookit Disc Pad 05776 is 6" (tapered edge)
Hookit Low Profile Disc Pad 05755 is 5" (almost flat edge)
Hookit Low Profile Disc Pad 05756 is 6" (almost flat edge)

All the above pads are velcro backed.

Porter Cable sanding pads:
5" standard (solid) adhesive-backed (non-velcro) pad 13700 (comes with 7424sp, 7335)
6" standard (solid) adhesive-backed (non-velcro) pad 16000 (comes with 7336, 7336sp)

5" 5-hole Hook & Loop (velcro) pad 15000 (standard), and pad 15001 ("contour" type - softer, thicker for PC's really thin polishing pads)
6" 6-hole Hook & Loop (velcro) pad 18001 (standard) (comes with Griot's 7336 PC), and pad 18002 ("contour") (comes with Coastal Tool's 7424 bonus kit)

Porter Cable counterweights (see above for equipped models):
5" Counterweight 874011
6" Counterweight 699933
Counterweights are attached with 2 Torx screws, size 15 ( T15 ). *

Coastal Tool's PC Accessory Page
Coastal Tool's informative "short & skinny" on the PC
Porter Cable Sander Accessories Porter-Cable.net page showing all PC accessories with short descriptions.
Amazon.com Click on Tools & Hardware, then input the Porter Cable part numbers in the search box to see large pictures of any of the above PC accessories.

Two of the most popular PC kits and backing pads (or backup plates ) are the ones from Meguiar's and CMA. While it has been recommended in the past to match the counterweight to the diameter of the backing pad, recent posts (deleted by the server outage) have shown users to be happier with using the heavier 6" counterweight with the 5" Meguiar's backing pad. They report less vibration and smoother running at higher speed settings with this combination than when they were using the 5" counterweight. This seems to be the smoothest running combination (5" pad with 6" weight) especially at higher speed settings. A combination of a 6" pad (such as the CMA pad) with 6" weight also performs very well and is preferable to using the 5" weight. I spent some time testing some various combinations of weights and backing pads in this thread: PC Vibration Test which reinforces what a small number of users have told me about the 6" weight/pad combo. The current recommendation for buying a PC is to simply buy a 7336 series model or buy the PC 7424 Bonus Kit from Coastal Tool. This kit includes an extra 6" counterweight and the 18002 velcro backed sanding pad, which means you do not have to buy a separate backing plate. Alternatively you can try buying a 6" counterweight separately if you own a machine equipped with the 5" weight. People used to have trouble in the past where they had to buy a separate counterweight once they bought a 7424 and the 6" CMA kit. Buy a 7336 or Coastal Tool kit and save yourself the trouble. Your local Lowes hardware store in the US has also frequently been cited as a favourite place to locally buy the 7336SP for a low price, but unlike the Coastal Kit, it doesn't come with a velcro plate.

Failure to get a well balanced combination of counterweight and pads MAY result in increased wear and shorter life for your PC (not to mention sore hands), especially if you run it at high speeds a lot. That is not to say you absolutely cannot use a 5" weight and your PC will self-destruct instantly, but it may not be best in the long run and it just doesn't seem to be the best handling setup. The owner's manual also recommends that you have your PC inspected and serviced (if needed) after about 100 hours of usage by an authorized service center.

Both 5" and 6" backing pads will work with commonly used 6.5"(or even 8") polishing pads. They do not have to match their diameter or anything, just stay firmly attached.

Some people have been attempting to make their own velcro backing pads by using self-adhesive velcro adapter (or conversion ) kits that have a "hook" pad which sticks onto the sanding pad that's included with some PCs. (Note that all the above PC backing pads are actually for sanding.) While these are meant to be used for quickly changing sanding discs, some have already used this to successfully attach foam buffing pads. One thing that lends validity to this idea is the fact that Griot's Garage equips their 7336 with the Porter Cable 18001 velcro sanding pad. Several other "real" velcro backing pads seem to look suspiciously like conventional sanding backing pads.

Here is an example of this being done: Making your own velcro backing plate for a PC? I have tried this myself, and find it does work, although because of the strong grip between the two velcro surfaces it can tend to pull the adapter away from the backing pad if you're not careful.

Likewise, the above listed 3M Hookit backing pads are supposedly for sanding, but Shiny Lil Detlr likes this pad better than the Meguiar's pad (which some say have failure problems). Hookit is NOT to be confused with the Hookit II system which has the hooks and loops reversed! 3M Hookit II Difference In 3M's automotive section, their backing plates listed seem to be for rotary buffers and have an incompatible shaft attaching size.

I have also seen some various backing pads that are generic or made by other brands (mostly sander accessory makers). Since I don't think there's anything particularly specific or special about 3M or PC sanding pads I'm sure these will also work. A few pads I've seen even say that they will work on other brand's sanders. Just be sure to get the correct 5/16-24 thread type and make sure it's for an orbital (or "dual action") sander. These may or may not require a velcro adapter.

* Occasionally some people get an oddball PC with a mismatching counterweight (ie, 6" on the 7424) or different sized Torx screws (try T20 if T15 doesn't fit).


SIDEBAR: What's that funny black washer for? Some people who have already purchased their PC's have been bewildered by this odd plastic or fiberboard washer that comes with their machine. According to Porter Cable, it is intended to fit between the backing pad and the spindle. The PC I bought came with this washer pre-installed on the backing pad, but often it's loose in a bag. My personal theory for why it goes here is so that it gives additional clearance between the pad and unit so getting the wrench in between them is easier.


FOAM PADS AND KITS

I'm going to try to keep this short since others will know more, and the hardest part about PC ownership seems to be just trying to get the pads on! I've only included the smaller 6" (really 6.5") pads because they are the most handy and popular, although some prefer the larger 8" size for some jobs. This listing is NOT exhaustive, as there are lots of other makes and types of pads available out there (CMA alone has many other types).

CMA 6.5" Durofoam Variable Contact (VC) foam pads:
These pads have a dish or depression on the middle face of the pad so that they are not flat, but slightly concave - hence the "variable contact" name.
- Lambswool Leveling Pad 77-216
- Yellow Cutting Pad 46-570VC
- White Polishing Pad 46-670VC
- Grey / Gray Finishing Pad 46-770VC
- Porter Cable Accessory Kit DM-KIT (includes 6" backing pad, 1 cutting pad, 2 polishing pads, 1 finishing pad, 1 lambswool compounding pad, 2 terry bonnets)
- Detailing Accessory Package DAP-KIT (identical to above but no 6" backing pad)
- It's worth noting that Lake Country manufactures CMA pads. If you'd like to know the exact specific type of pad that any of the above are, note the CMA part number matches the part number you can find on the Lake Country website.

CMA 4 Inch Spot Repair Pads:
CMA sells these neat little pads with their own 3.5" diameter backing plate. The pads are only 4 inches big, so they're designed for repairing scratches and handy for polishing in tight areas. Not a lot of mention on the forum about this yet, but it sounds like a good idea. http://www.properautocare.com/4inspotreppa.html

Meguiar's 6.5" Softbuff foam pads:
These pads are flat faced pads, unlike the CMA ones. 8 inch pads are specified by replacing the "6" with a "0" in the item number.
- Lambswool Cut 'n Shine Wool Pad W-4006 (yes, they DO make this!)
- Maroon / Red / Purple Cutting Pad W-7006
- Yellow Polishing Pad W-8006
- Tan / Beige Finishing Pad W-9006
- Set of 3 Pads WDAV99-B (includes 2 polishing pads, 1 finishing pad)
- WDAV99 (identical to above kit but includes 5" backing pad and reportedly costs $8 more)

Porter Cable 6" OEM foam polishing pad:
White polishing pad with integral (permanent, possibly 5") backing plate, part number 54745 Even though Coastal Tool claims that this pad may be used with either the 5" or 6" counterweight, I have determined that (based on 2 members' experiences) that this pad works smoothly only with the 5" weight and vibrates excessively at high speeds with the 6" weight.
Porter Cable also makes a 6" lambs wool velcro backed polishing pad part number 18007
Porter Cable Polishing Pads Porter-Cable.net page showing PC polishing pads mentioned above.

3M makes good pads, but only their 6.75" Perfect-it DA Glazing Pad 05729 is smaller than 8 inches. It appears that this pad is intended for use only with glazes and wax application, not polishing, so it may not be best suited for that use. Several members here like these type of pads with their convoluted foam face design that looks like fingers or a waffle type. These other pads are meant for rotary buffers and are 8" or larger, but might work with the PC.

Link to all of 3M's polishing stuff (except backing pads)
http://products3.3m.com/catalog/us/...ler/output_html

There are also many other pads and backing pads available from other vendors such as Top of the Line and 4 Star Products Premium Auto Care. Unfortunately Motorhead.net has gone out of business. Lake Country Mfg is the actual manufacturer of CMA's pads and for a few other companies. If someone would like to write up a pad comparison between makes please be my guest!


LINKS

www.properautocare.com (aka CMA)
www.meguiars.com (also have a tutorial about PC usage)
www.griotsgarage.com (be sure to download his useful guide to PC usage in PDF format)
www.portercable.com
www.coastaltool.com

Geekysteve posted this later on in this thread, but here it is for easier access:
PC How-To (Basic) Geekysteve's PC Usage Guide posted over at Roadfly

Also check out Alboston's Buffing out swirl marks and scratches with your Porter cable 7336 article also posted in the Member Articles section.

I hope this is useful to everyone and if anyone would like me to make any corrections, additions, or would like to comment PLEASE shoot me a PM and I'll edit my post!
Thanks