I had the PC with my 6" backing pad and I had a Harbor Freight ( don't laugh ) with a 4" backing pad. Since I got the Griots G9, the PC will be my 4" machine. I gave the Harbor Freight to my son in law, he loves it. The Harbor Freight is a pretty decent machine especially since I only paid $47.00 for it with a 20% off coupon. I was impressed, I thought it was comparable to the PC.

 

Exactly what I am doing. I added a 3" LC backing plate and use 3.5" pads on my PC now. Just used it last week to detail my friend's Harley. The PC worked great with small pads!

 

If you plan on using a wax/sealant you'll likely use yours once it twice a year on a given vehicle. Go with an 'average' coating, maybe every other year, longer if you go with a more durable coating.

This is barring an unfortunate 'incident' out in the harsh world. With our coated cars, I expect my daily driver wouldn't see a polisher for the next 2 years, 'hobby' cars, 3-5 years.

All bets are off if I find a new coating to try or something else that intrigues me. Now that I've found what works best for me, I dont find myself as interested in doing friends cars much anymore. Was fun at first, not so much anymore.

As to how many times you can correct your paint, as mentioned...it depends. As an example, when I first got into this stuff one if the first cars I did was our black 2004 Corvette that had etched water spots in the paint (Thanks, Zaino.. you might look good but you ain't worth nuthin' as far as protection goes). First went over it w microfiber pad, Megs D300 followed by Wolfgang Finishing Glaze (light polish, kinda like Menzerna 3500) using GG 6" DA.

Coated it with WG Uber Ceramic (decent coating but WAY overpriced). A few months later wanted to try better coating so went over it with Menzerna 2400 & orange light cutting pad followed by Menzerna 3500 on white polishing pad, Flex 3401 forced rotation machine. Coated with Feynlab Ceramic.

That didnt really blow up my knickers so the next Spring, removed the Feynlab Ceramic with Megs M101 on orange light cutting pad followed by Sonax Perfect Finish on yellow Rupes pad w Rupes 15 Mk2, coated with Kamikaze.

At that point, was dangerously close to burning thru on panel edges so figrd that was about all she wrote as far as correction goes, paint likely didnt have another heavy compounding in it without making for a really bad day. Probably could have got away with another go with a medium polish on polishing pad but woulda had to have been REALLY careful.

Just for giggles, right before we traded in wifes black, 2005 Mazda 3 decided to see what would happen if I really went at it. GG 6" DA, purple foamed wool pad and Megs M101...really leaned into the machine, lotsa pressure.. took about 8 passes to burn thru clear on flat surface if trunk lid. That answered that question 😄

 

Not trying to hijack the thread, but I would like to the same thing with my old PC. I pulled it out of the toolbox today and noticed it had the older model pressure bolt and not the threaded backing plate connector. It also says to use only 5” pads but I will live dangerously if I can find an older style 3” backing plate. Do they still even make them?

 

I run my 3" backing plate with my 5" counterweight and it runs fine. The counterweight concerns really only apply when using the PC as it was originally intended---when sanding. Not sure if they make the old-style plates for the PC. You might want to look at the plates for other brands that use a similar bolt. Maybe some of the rotary machines.

 

About once every 3 to 4 years at the moment....

 

I've been detailing since 2001, and actually made a business out of it in 2018. I have found that the Porter Cable 7424 is good at handling light paint correcting issues, but it gets very hot and just doesn't have the power to make serious corrections (straight line scratches, heavy spiderwebbing). I use the Flex 3401, as it is a combination of a rotary and DA random orbital. It's a heavy machine, but doesn't need to go higher than speed 4 for almost anything I use it on. The best ingredient to consider in this recipe for polishing is your pads! There are many from which to choose, and they can be the difference between a good job and and a great, efficient job!
I am seriously looking at adding the Griot's G9 to my stable of polishers, as it is reasonably priced, has many user-friendly features, and FYRARMS gave it a great review! My current 15mm long throw DA is the Adams Swirl Killer, and I have a 3" mini Swirl Killer for smaller spaces. Both of those tend to bog down fairly easily, so I find that I start with the Flex and go from there. The Porter Cable is now part of my retired collection of tools; it helped me learn the basics and now has earned a nice rest!
I applied the Optimum Gloss Coat ceramic coating (the non-professional product) mainly as a tester to see how well it could do, before I offer it to my clients. I'm very pleased with it so far, and I won't "need" to use the polisher on it (unless something really abrades against the finish!). I've been giving the car a regular rinseless wash with ONR (Optimum No Rinse) and the big ed sponge. My clients often ask for a basic polish package, so I use the Flex regularly.
Even if you only use your machine once a year, it's so much nicer to use a good tool to make the experience enjoyable and more rewarding with better results from less "effort". You'll most likely want to do the job with a great tool, instead of dreading, and perhaps, putting off the chore of using a cheap tool.