Is this normal for a PC 7424xp?

[DavisBladeWorks]

Hey guys, I tried out my new PC for the first time yesterday and I must say that I got great results (I used it to restore the headlights on my wife's G37).

I did notice something that I haven't seen when watching videos... Most people say to apply pressure with the machine - I have to do the complete opposite and lift up on the machine a little to get the pad to spin. (I use a thick black line to determine spin)

Likewise, when I use speed setting 2 to spread compound, I literally have to take the machine OFF of the surface to get the pad to spin. In other words, I can't spread compound because the pad just vibrates.



In addition, I did polish paint a little with the orange pad and M105 and I ran into the same issue. At speed 5 on a completely flat surface it seemed to work fine, but if the surface had a dip or curve in it the pad would seem to lock up and vibrate. Is any of this normal?

From what I've seen people have to apply a fair amount of pressure to slow the pad down.....that's definitely not the case for me.

[Evan.J]

Do you have the washer on the backing plate?

[DavisBladeWorks]

Do you have the washer on the backing plate?

I'm assuming you're talking about the grey fiber washer. If so, yes.

[Evan.J]

What size pads?

How much product are you using on the pads?

[Kacz]

You use enough pressure for the pad to spin a certain speed.

This is how someone presenting a video should say it: Put a black mark on the backing plate and apply enough pressure so your pad spins this* fast on this** size backing plate.

*this meaning showing you how fast it's actually spinning
**this meaning whatever size backing plate they're using.

If that makes sense.

Someone in a video shouldn't say something vague like "Apply a good amount of pressure"...they should be specific like I said earlier.

[Kacz]

Yes it's normal on a contour for the pad to stop spinning because of the pressure you're using.

I'm not sure how to explain it, but it's something that you can play with to see what kind of pressure you need in certain areas.

Maybe there is a thread on here that can better explain with a video or pictures.

What size backing plate and pads are you using?

And can you make a video with your technique?

[DavisBladeWorks]

What size pads?

How much product are you using on the pads?

About 4 pea size drops to start with, then I refresh it with about 3 drops.


You use enough pressure for the pad to spin a certain speed.

This is how someone presenting a video should say it: Put a black mark on the backing plate and apply enough pressure so your pad spins this* fast on this** size backing plate.

*this meaning showing you how fast it's actually spinning
**this meaning whatever size backing plate they're using.

If that makes sense.

Someone in a video shouldn't say something vague like "Apply a good amount of pressure"...they should be specific like I said earlier.


Well the problem isn't that I don't know the amount of pressure to use, it's that ANY pressure at all (even the weight of the machine itself at slower speeds) stops the rotation completely.

[DavisBladeWorks]

Yes it's normal on a contour for the pad to stop spinning because of the pressure you're using.

I'm not sure how to explain it, but it's something that you can play with to see what kind of pressure you need in certain areas.

Maybe there is a thread on here that can better explain with a video or pictures.

What size backing plate and pads are you using?

And can you make a video with your technique?

I'm using the standard yellow backing plate (5 inch) that everyone has (lake country I think?) and lake country pads (5.5 inch). I'm using the kit that you get from autogeek that includes the machine, orange and black pads, backing plate, and M105 and M205.


Yeah I can make a video tomorrow afternoon to show what I'm doing.

[Evan.J]

Here are 2 articles and some videos in the second one. Compare yourself to mike to see what you might be doing wrong

here is the trouble shooting guide

http://www.autogeekonline.net/forum/auto-detailing-101/37769-da-polisher-trouble-shooting-guide.html

Here is a DA guide with videos:
http://www.autogeekonline.net/forum/tricks-tips-techniques/20021-definitive-how-article-removing-swirls-scratches-water-spots-using-porter-cable-7424xp-g110v2-griot-s-garage-polisher.html

[DavisBladeWorks]

Ahh! Also forgot to mention that in certain areas the pad will not only stop spinning, but reverse direction for a second until I lift up and take the weight of the machine off the pad.

I only mention that because I've never seen that happen in the 30+ videos I've watched of people using the PC.

[Kacz]

Ok that's good.

I'm thinking that maybe the issue could be applying uneven pressure.

Example: Applying too much pressure on the edge of the pad which will stop it from rotating correctly. (Pad isn't evenly flat across its surface)

[af90]

Are you using the handle that comes with the machine?

[DavisBladeWorks]

Are you using the handle that comes with the machine?

No.

[1fastTbird]

As someone who, like you, earlier this year bought a AG "perfect Starter" PC 7424xp kit and started the learning process, I have found the following:

The LC 6.5" pads are not a good match to the machine and should have not been included in the starter kit; waste of money with the PC. I have switched to lower profile LC 5.5" and have had much better success. Since you have the 5.5" pads clearly not the problem

I have had a lot of trouble getting the PC 7424xp to demonstrate proper rotation working on speeds under the 3.5 - 4 range when applying any pressure, so reading that you are having problems at speed 2 is not at all surprising. I am sure that is due to my lack of experience, but I think you need to increase the speed and have confidence in the machine and your hand speed.

[DavisBladeWorks]

As someone who, like you, earlier this year bought a AG "perfect Starter" PC 7424xp kit and started the learning process, I have found the following:

The LC 6.5" pads are not a good match to the machine and should have not been included in the starter kit; waste of money with the PC. I have switched to lower profile LC 5.5" and have had much better success. Since you have the 5.5" pads clearly not the problem

I have had a lot of trouble getting the PC 7424xp to demonstrate proper rotation working on speeds under the 3.5 - 4 range when applying any pressure, so reading that you are having problems at speed 2 is not at all surprising. I am sure that is due to my lack of experience, but I think you need to increase the speed and have confidence in the machine and your hand speed.

Thanks for the input. I may actually be using the 6.5 inch pads. I'll go measure and report back.