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Y2KSVT
10-01-2010, 03:37 PM
Hi Mike,

So I've polished out two cars now, my own and then my wife's. I started with my own car and did everything on speed 5 with my PC7424XP. I was able to put enough pressure on it to get the pad to just slowly spin, and I was showing great results. I did the entire car with M105 and an orange pad. I am noticing in a few small areas where I have some micromarring, where I'll go over with M205 and a white pad.

Last weekend I polished out my wife's car with M105 and a white pad, as she had very minimal swirls. About half way through, I decided to see what speed 6 could do. Wow, what a huge difference in speed! There was no way I could put enough pressure on it to slow the pad down to a slow spin.

It was about the time where I moved up to speed 6 that I really felt comfortable with the polisher. I could tell that I was being a lot more efficient with everything I was doing.

I'm not sure how to ask this as you may not be able to answer it without seeing my technique, but do you feel that I was removing swirls faster because of the higher speed setting of 6, or because I was more efficient after getting some time behind the polisher? Do you suggest speed 6 to speed up the work? I guess speed 5 seems so slow after moving back down from 6, that I'm questioning whether it's not all in my head.

Mark

BillE
10-03-2010, 06:21 AM
Good question.

I am by no ways any sort of expert, so take this for what its worth.

Every thing I've read about 'speed 6' and above is that it is 'hard on pads.' I have on occasion gone super sonic, just to 'see what happens.' But chickened out after a wee bit.

That being said, I have no idea what 'being hard on pads' means. My guess is the higher speed (read, more torque) is trying rip the Velcro away from the pad/backing plate. Me thinks the foam will take it...rotaries use a high torque, right? So that leaves the Velcro interface.

Just a WAG, but sounds good to me.

Bill

Setec Astronomy
10-03-2010, 08:32 AM
DA's are harder on pads than rotaries, because the oscillating (back and forth) action heats up the pad/backing plate interface. In the old days there were some pads and backing plates that weren't so good and that heat could melt the backing plate and/or delaminate or heat-damage the pad.

This could theoretically be worse today with the more powerful machines, but I don't think they make that particular backing plate anymore, and most of the pads today seem to have the heat-bonded rather than glued velcro, so in most cases you should be good at speed 6, and yes, you will do more correction at that speed.

That's not to say that you won't heat things up more at speed 6, and possibly get shorter life out of the velcro and plate. It's always prudent to periodically feel things to see how hot they are getting and perhaps changing pads to let things cool off a bit if things are getting too hot.

Since you seem to have addressed this question to Mike Phillips (his "ask the expert" forum is elsewhere), I believe Mike still advises you don't go over 5, but he'll have to speak for himself.

ScottB
10-03-2010, 08:37 AM
I still find that with PC and PC-XP you need higher speed settings for best results. Now thats personal indeed, and yes I am using 5.5 inch pads and 5 inch backing plate.

Y2KSVT
10-03-2010, 04:13 PM
Thanks for the replies, guys. I'm still somewhat new, so I guess I directed it towards Mike, knowing that I should get a reputable answer back. That's not to take away from any of you, but I haven't really figured out who has been in the game a while, or who has experience with this particular machine.

My guess was that speed 6 should work fine, and I always thought it was kind of a selling point for the XP version, as it has more power than the standard PC7424. People also talk about the Griot's Garage polisher as having more power than the PC7424XP, so maybe I'm confusing "speed" for "power," but what's the benefit of more power (speed 6) if you aren't supposed to use it?

Anyways, I think you guys for replying. I was able to get nice results with speed 6, and it really helped me (or so I think) cut a lot of time off of detailing a car. If anyone still cares to comment on provide their thoughts, it would be much appreciated. Thanks!

Mark

09I30cw
10-03-2010, 05:42 PM
I tried speed 6 one time...melted the back plate and the pad. The car was badly oxydized, and i wanted to get it faster...witch did'nt work out.
So i backed to speed 5 took my time. Live and learn :)

Impressions
10-03-2010, 06:32 PM
with the right pad and amount of chemical you should be able to use 6 all day long
too much pressure for extended times will melt the adhesives from bp

Setec Astronomy
10-03-2010, 08:53 PM
People also talk about the Griot's Garage polisher as having more power than the PC7424XP, so maybe I'm confusing "speed" for "power," but what's the benefit of more power (speed 6) if you aren't supposed to use it?

Part of the confusion is that the PC was originally and primarily designed as a sander; in that application there is no velcro or foam, there is a backing plate that takes adhesive sanding discs. There was at least one brand of backing plate that really couldn't take the heat generated in the foam polishing pad situation, hence the restriction to setting "5".

AFAIK that backing plate isn't made anymore, so it's not an issue. You can still get things hot if you're doing a lot of work, and if you hit the right combination of factors I'm sure you can still get yourself into trouble, particularly with these newer, more powerful machines. There are many people who never work at less than 6 for defect removal.