First 7424 backing = toast, what did I do wrong?

markw78 · 08-16-09, 05:58

I'm assuming this is why you never really see videos or hear of people using speed 6...

Was polishing the trunk lid and started getting yellow foam all over, I assumed it was the pad falling apart (yellow lake country pad), but it looked ok. Shortly after I found that the part where the threaded stud attaches to the disk was shreaded and falling apart, can almost pull it out now.

Is this from using the fastest setting? Is there a better backing that will hold up to the fastest speed? It broke down the polish and worked much easier going from 5-6, though my hands are still vibrating I think

anyways what backing should I order, I still have the 5, 6.5" lake country pads I bought and have only used 3 of them once so I'd like to stay compatible. I have a 5" and 6" counterweight. or do I just have to get the same one and keep it down to 5?

dheath · 08-16-09, 06:22

Never heard that before, sounds like a random isolated incident. I have a 6" and a 4" and never had a problem.

khjr · 08-16-09, 07:06

If you do a search, you'll find that a number of posts where people have had their backing plates disintegrate. I didn't get the impression that their failures were directly attributable to speed or loading, as opposed to poor manufacturing or quality control. I'm not certain that your failure was either. If you were really abusing it to that extent, I'd be more concerned for your paint than the backing plate.

JBM · 08-16-09, 07:33

I once melted my pad to the backing plate because some polish got inside the centering hole on the pad. Is there any chance the backing plate got wet in any way?

Also every time i try speed 6 i struggle. Polish dries out too fast, gums up the pad, dusts too much. Maybe its me....dunno

Legacy99 · 08-16-09, 07:42

I've had the lc and 3m break. Trying the Meg's bp.

scary bill · 08-16-09, 09:53

I noticed that my LC BP get hot fast when working the PC hard. Speed 6 also puts a lot of shearing force (horizontal)on the BP, this would be multiplied by the grabby yellow cutting pad.

6.5" pads always seem to big and heavy for me with the PC, and it bogs down. I have used 5.5" low-pro pads, and they work better. If you want real correction you should get 4" pads as it will work better. Some orange and white pads, I stay away from yellow, too.

Dave1 · 08-17-09, 06:38

Quote:

Originally Posted by markw78

Is this from using the fastest setting?

No....

Using speed six will not shread backing plates.......

Sounds like you just got a bad one.....

Kean · 08-17-09, 09:02

....several years and I've never had an issue using speed 6. ....scary thought though.

Legacy99 · 08-30-09, 04:21

Just broke another 5" LC backing plate. Broke a 4" also. All on speed 6. Using a new Meg's 5" bp, hope it lasts. Also broke a 3m 5" bp. The 3m bp got so hot it melted the center of the bp and melted a brand new ultrafina pad. My old lc bp lasted over a year using speed 6 a lot, but finally craped out too.

markw78 · 09-01-09, 11:45

I ended up ordering the LC BP's Porter Cable 7424 Backing Plates- Dual Action Hook & Loop backing plate for your porter cable 7424, The best backing plates for the Porter Cable 7424 and so far so good, the 5" had the metal plate like the 3.5" even though the picture doesn't show it.

So far so good, used speed 6 a little this last weekend with the 3.5" BP.

SoCalB6 · 09-01-09, 12:09

This same thing happened to me. Luckily I caught the problem before any metal from the lodged threaded part of the bp could have seriously damaged the car. It was kinda funny watching the bp with the pad still attached flying off, like WTF? It could have been real ugly. I called Autogeek and they sent me an Edge HD bp. I didn't like it, but it sure was a lot tougher.