Rotary vs. PC for Finishing Polish

I

imported_Dave KG

New member
Decided to compare the finish achieved by the rotary and the PC suing a couple of finsihing polishes:



Tools: Makita 9227CB; Porter Cable 7424

Polishes: Meguiars #80 Speed Glaze; Menzerna PO85RD Final Finish





Meguiars #80

A light cutting polish, there are lighter abbrassive in the Meguiars range but the #80 makes a very nice finishing polish owing to the oils it also contains to leave a lovely wet look shine too.



By PC

This was applied using a Meguiars W8006 Polishing pad. Spread on speed 3 and then several passes on speed 5 until the residue went clear to indicate the product had fully broken down and was ready to remove. The results:







and in the sun:







While the finish is excellent by PC, very close examination of the Brinkmann shot above shows a very very slight micromarring, which very slightly detracts from the finish. In sunlight, this is hard to pick up, and under the Brinkmann the worst of this is masked by the metallic flake.



By Rotary

Again, applied with a Meguiars W8006 Polishing pad. Spread at 600rpm, then polished at 1200rpm to thoroughly work the polish with light to medium pressure... Two final passes made at 1500rpm, and tehn the rotary stepped back down to 600rpm for two final passes to refine the finish. The results:







and in the sun:







Here, very close examination of the finish reveals a cleaner finish, free of the slight micromarring left by the PC and allowing the finish to look just that little bit better... The difference is small, but under close scrutiny, its definitely noticeable using Meguiars #80... The rotary finish being just a little bit sharper and clearer than the PC IMO.





Menzerna Final Finish PO85RD

The finest polish for finishing in the Menzerna range, and IMHO, the best finishing polish on the market today.



By PC

Applied using a Meguiars W9006 finishing pad. Spread at speed 3 and then five passes were made at speed 5 with light to medium pressure. A pass on speed 6 was made, and then a final pass on speed 5 at which point the residue was clear. The results:







and in the sun:







Again, the finish left by he PC here is excellent with lovely reflections in the sunlight... However, close examination under the Brinkmann does reveal a very slight amount of micromarring again - very very slight, hardly noticeable in fairness but it is there. This isn't ruining the finish at all, and in the sun it looks glossy and lovely, but it can be just ever so slightly better.....



By rotary

Again with a Meguiars W9006 finishing pad. Spread at 600rpm, then polish worked in at 1200rpm with light to medium pressure for several passes. Two final passes were made at 600rpm to refine the finish. The results:







and in the sun:







Under the Brinkmann light the micromarring visible in the PC finish is not there, allowing for a sharper reflection, a more crystal clear finish. This also lead to slightly clearer and sharper reflections in the sun shot. Now, as mentioned throughout, this difference is very small, but in my eyes, it is most definitely there.





To summarise - first of all, I am in no way saying that the finish left by PC is a bad one. It most certainly isn't!! By PC, you can achieve an excellent finish and your car will be the talk of the show. However, with care and attention to finishing techniques, the finish by rotary is just that little bit better... Its a small amount, but its slightly better and for me this warrants perfecting the rotary finishing technique and finishing cars by rotary wherever I can. :)
 
IMO what you are seeing left over from the PC isn't micro-marring caused by the PC but rather cob webbing that wasn't removed. You can test this yourself by polishing a panel w/ rotary and following up with a DA machine.
 
A rotary will finish brighter and clearer than a PC. The Cyclo comes really close to the rotary in this respect. Finishing with the rotary and not having any trails? Lots of practice!
 
this just shows a great example of the capabilities of both machines. great write up and what kind of test car is that?
 
MichaelM said:
IMO what you are seeing left over from the PC isn't micro-marring caused by the PC but rather cob webbing that wasn't removed. You can test this yourself by polishing a panel w/ rotary and following up with a DA machine.
Click to expand...



Actually, I'll bet money he's done this...I know I have...and that's when the micro-marring is most niticable. If David replies, I'll bet he'll confirm that the micromarring is millions of little 1/8" lines with a slight curve to them (following the motion of the DA).



This micromarring doesn't always occur, as it very much depends on the paint hardness and color, as well as polish and pad selection...not to mention pressure and technique. But on really dark colors it happens often. For those persons not confident in their ability to finish down halogram free on a dark color, I recommend making a couple passes with the rotary (1000RPMs) and then quickly pick up the PC and make two more passes...thus allowing the rotary to perform the initial breakdown of the abrasives (since the rotary doesn't change direction, the abrasives wont dig in and make those marks).
 
Oh yeah, funny that you say you didn't notice it in the direct sun. When the micromarring is present, in the direct sun it show up as a "haze" but under halogen you don't really see the haze but you can see each of the individual gashes if you get up real real close to the paint and look from different angles.
 
SpoiledMan said:
A rotary will finish brighter and clearer than a PC. The Cyclo comes really close to the rotary in this respect. Finishing with the rotary and not having any trails? Lots of practice!
Click to expand...





I think you have wrong, just use a finishing pad and a good polish like Menzerna PO85RD and low rpm, then you are safe.
 
porta said:
I think you have wrong, just use a finishing pad and a good polish like Menzerna PO85RD and low rpm, then you are safe.
Click to expand...





Not on all paints.



I've had issues with certain non-metallic balck paints, that my only solution was to break out the PC.
 
RAG said:
Actually, I'll bet money he's done this...I know I have...and that's when the micro-marring is most niticable. If David replies, I'll bet he'll confirm that the micromarring is millions of little 1/8" lines with a slight curve to them (following the motion of the DA).



This micromarring doesn't always occur, as it very much depends on the paint hardness and color, as well as polish and pad selection...not to mention pressure and technique. But on really dark colors it happens often. For those persons not confident in their ability to finish down halogram free on a dark color, I recommend making a couple passes with the rotary (1000RPMs) and then quickly pick up the PC and make two more passes...thus allowing the rotary to perform the initial breakdown of the abrasives (since the rotary doesn't change direction, the abrasives wont dig in and make those marks).
Click to expand...



I know exactly what your saying. I've struggled with this problem many times on dark colors especially black. I find I have to use a finishing pad with a fine polish to produce a clear finish. I find that it has to do with how soft the clear is rather than color, it's just that you will notice on dark colors and not on light colors.
 
joyriiide1113 said:
Not on all paints.



I've had issues with certain non-metallic balck paints, that my only solution was to break out the PC.
Click to expand...



This past Saturday, I was working on a black BMW that had been repainted. The paint would get bright and clear with the rotary, white Edge pad and 85RD or FPII or 106FF or RE5 but the trails wouldn't go away as the paint was the softest that I've ever worked on. I didn't even bring pads for my Cyclo so it wasn't an option. The PC hazed the surface with whatever pad/polish/speed combination I tried. I spent 4.5 hours on half a hood so that lets you know that I didn't quit easy. :o
 
Dave KG- Yeah, those are really good pictures and your write-up was super :xyxthumbs



And that paint makes me think BOOORING! when I consider my silver cars :o It'd be fun to work on something so attractive for a change!



The light marring I could see (thanks to the good lighting and right camera angle) looked like *both* leftovers and final-polish-micromarring to me, but without *being there* it's hard to say. Some of the marring looked linear while some of it looked like the sort of initial-bite thing that the PC can leave but the rotary (and usually the Cyclo) won't.



One Q: when you say "passes" do you mean "reapply product"-type passes or "just work with what's already on the pad"-type passes? What I mean is...did you reapply more product for the work at different speeds or not? Trying to get a firm handle on how you did the work...
 
Accumulator said:
Dave KG- Yeah, those are really good pictures and your write-up was super :xyxthumbs



And that paint makes me think BOOORING! when I consider my silver cars :o It'd be fun to work on something so attractive for a change!



The light marring I could see (thanks to the good lighting and right camera angle) looked like *both* leftovers and final-polish-micromarring to me, but without *being there* it's hard to say. Some of the marring looked linear while some of it looked like the sort of initial-bite thing that the PC can leave but the rotary (and usually the Cyclo) won't.



One Q: when you say "passes" do you mean "reapply product"-type passes or "just work with what's already on the pad"-type passes? What I mean is...did you reapply more product for the work at different speeds or not? Trying to get a firm handle on how you did the work...
Click to expand...



Many thanks for the kind words, especially about the photography as am not by any stretch of the imagination a good photographer, takes me a lot to work out what camera angle and lighting to use...



Sorry mate, to be a little more clear on what I meant by passes - this probably isn't the correct meaning of the word, but what I was meaning was one movement of the polisher back and forth across the area... So with one application of product I would make many passes to break it down before stopping and reapplying.... I refer to each application of product as a "set" - as in set of passes, not sure if that is right?
 
mr.ikon said:
this just shows a great example of the capabilities of both machines. great write up and what kind of test car is that?
Click to expand...



I'm afraid I have no idea of the kind of test car - its just a bonnet I got free from the local bodyshop. I choose this colour as it has a metallic flake, and the flake can actually hide very effectively the slight micromarring so it was just to try and show that even on metallics the rotary finish is slightly better... If you try this on a solid dark colour like black or red, the difference will be even more pronounced.



I will source out a solid colour panel and repeat the test - I had a colid red door, but did a demo of the brutality of Power Gloss on a wool pad for someone, and lets just say the paint on the door isn't really fit for testing anymore!! :eek:
 
I too have noticed this micromarring but mainly on solid colours as I am convinced it actually happens on all paints to some extent when using the PC but metalic flake can hide the marring whereas it shows up 'worse' on solid colours.



This is an example on a solid blue door after use of the PC and ssr1.



Claybarmishap011.jpg




With a rotary I can achieve flawless sharp finishes and with a cyclo somewhere between the two.
 
Brazo said:
I too have noticed this micromarring but mainly on solid colours as I am convinced it actually happens on all paints to some extent when using the PC but metalic flake can hide the marring whereas it shows up 'worse' on solid colours.



This is an example on a solid blue door after use of the PC and ssr1.



Claybarmishap011.jpg




With a rotary I can achieve flawless sharp finishes and with a cyclo somewhere between the two.
Click to expand...



And i'm also glad to see that I'm not the only one who gets micromarring like that from Poorboys SSR products when using the PC - I find them much much worse than Meguiars, Menzerna, Pinnacle in this respect which is why I no longer use or recommend the SSRs.
 
I too see that same micro marring with my pb stuff, When i use megs. it disapears nearly entirely. At first i attributed this mostly to lack of skill. Which it could still be, but time after time megs seemed to edge out PB stuff.



I'm looking to fully switch over to menzerna. I'd like to try it all then.
 
Dave KG- Thanks for explaining what you meant by "passes". And you really *did* capture some mighty subtle flaws in those pictures, which isn't always easy for *anyone*.



Brazo- I wouldn't go so far as to say such micromarring *always* happens, just a matter of individual paint/product combinations; I've seen paint (including solid black ss) that was *perfect* without the use of a rotary. As I keep posting in thread after thread, there are just *so* many variables... FWIW the blue car you showed (another good picture, shows just what you were referring to) is a kinda extreme example that would've had me reaching for a different product. But hey, it's easy for me to say that, I wasn't there.
 
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