sremick:
I hate to bust your swirl-removing bubble, BUT the Porter-Cable Dual-Action orbital buffing machine (PC-DA as its abbreviated in this forum) while better than doing it by hand, is NOT a great machine for removing deep swirls and imperfections.
One "problem" it may have is the size AND age of the backing plate you are using. If you are using a 6" plate and corresponding pad size, the power of the rotation or orbit motion is being "lost" due to the flex or deflection of the backing plate. There is a tendency for a novice user of this particular buffing machine to bear down on it and get some pressure at the edge of the backing plate and pad to bit into surface to remove a defect. This causes the edge to "stall" and because you have a machine with a 4.5amp motor trying to power a 8mm stroke or orbit and the laws of physics simple will not allow it to "work" as you think it does at the edge. Add to this that a backing plate becomes more flexible/bendable with age because of all the heat cycles it goes through AND that the velcro hooks loose there "grabbiness" over time from continuous pad removal are more factors that are working against you with the PC-DA.
One way to avoid this is to use a smaller backing plate and pad. I use a 4" plate and pads with my very-old PC-DA. This creates an obvious problem: you don`t cover much area with a smaller pad and it will take longer to do an entire vehicle. It is VERY difficult to not want to put a lot of pressure on the plate and pad rather than let the machine orbital motion, pad type, and abrasive do the "work" for you. There is also the tendency to move the machine head (plate and pad) much too fast over an area that is being corrected or polished. Then you also have the "problem" of using too much pressure and overworking the pad because of the excessive heat AND/OR drying out the abrasive and it starts to dust (A much-maligned problem with early versions of Megs M105 compound).
So while correcting or polishing may appear not to be "rocket science", there is still a proper technique to it, and much like the game of golf, to get good at it you will need experience and repetition. A lot of it is,indeed, trial-and-error, especially if you are a do-it-yourselfer learning on your own.
One thing you will learn (and already have learned), what works great on one vehicles` paint may not on another. EVERY paint is different. That is why good detailers will do a test spot with different pad types (foam densities/hardness, cell opening, thicknesses, and face patterns) and different manufacturer`s abrasives until the "magic sweet spot" for correction or polishing is found. It`s obvious that for a hobbyist or do-it-yourself detailer that this is a very expensive proposition and expense few can afford.
In my very own Captain Obvious (my nickname) hypocrisy, I tend to take a self-taught one-pad, abrasive manufacturer, and technique/methodology (IE; one-size-fits-all) approach to using my old PC-DA, but the results speak for themselves;
I get the SAME results you are experiencing. They are not great, but they are "better" than before and sometimes you just need to accept that with a PC-DA, the pad, and abrasive you have and are using, this is as good as it gets. Can it be better? Yes, but that will take some experience by-trial and-error, and an investment in different pads and abrasives. No, as stated, it`s not rocket science, but if it were easy, EVERYONE could do it.
I have "upgraded" my abrasives from Meg`s M105 and M205 (long considered detailing favorites in this forum) to the Griot`s Garage BOSS (Best-Of-Show-System) Fast Correcting Cream, Correcting Cream, and Perfecting Polish. They work very well and if you want to try them out, go visit AutoZone and see if they are in stock for purchase. No, they are not "inexpensive" (AKA, cheap) but they are better than the Megs consumer line of Ultimate Compound and Ultimate Polish twins.
Another suggestion is to look into Megs Mirror Glaze Professional M110 Ultra Pro Speed Compound and M210 Ultra Pro Finishing Polish at an auto body supply store. Both are updated versions of M105 and M205. Most places, however, stock them in 32-ounce (quart) sizes, so again, they will be expensive.
Lastly, start saving up for a new polishing machine. If you are on the fence and just do not know what to get without spending a lot of money, Harbor Freights (Yes, that inexpensive(cheap) tool and machine place) has introduced a new forced-drive polisher, the Hercules HC109B Polisher. For more information, please reference this thread:
https://www.autopia.org/forums/deta...09b-forced-rotation-polisher.html#post2194140
), the PC is not time-efficient. Not at all. Well, *maybe* with 4" MF cutting disks. Maybe.