Shredded Backing Plate

[S04T]

Hey guys I have a bit of a problem that I am hoping someone can give me some advice. I bought a PC 7424 a week ago and got the SSR 2.5 stage done on the car. The backing plate seemed kind of warm during the first stage but I didnt think much of it (ruined a white pad, looks like it melted the fabric on the back of the foam pad). I started the SSR1 stage last night and after 5 minutes the backing plate tore in half right around the edge. I already have a 3M backing plate on order but my question is what am I doing wrong? :shrug: I dont think I was using much pressure other than the weight of the PC. Not enough pressure? Too much polish? Is speed 6 too high, should the PC be set on 5? On a side note, when I received the PC they included the 6.5" pads rather than the 5.5" Could this have been the cause of my problem since I used the 6.5" pads (on speed 6) for the SSR2.5? Sorry for the gigantic post but I have a car show in Steamboat Springs next weekend and I dont have time to screw this up again Thanks for any insight you pros might have!

 

[TransAxle]

Hey guys I have a bit of a problem that I am hoping someone can give me some advice. I bought a PC 7424 a week ago and got the SSR 2.5 stage done on the car.

1. The backing plate seemed kind of warm during the first stage but I didnt think much of it (ruined a white pad, looks like it melted the fabric on the back of the foam pad).

2. I started the SSR1 stage last night and after 5 minutes the backing plate tore in half right around the edge. I already have a 3M backing plate on order but my question is what am I doing wrong? :shrug: I dont think I was using much pressure other than the weight of the PC.

3. Not enough pressure? Too much polish? Is speed 6 too high, should the PC be set on 5?

4. On a side note, when I received the PC they included the 6.5" pads rather than the 5.5" Could this have been the cause of my problem since I used the 6.5" pads (on speed 6) for the SSR2.5?

Sorry for the gigantic post but I have a car show in Steamboat Springs next weekend and I dont have time to screw this up again Thanks for any insight you pros might have!

Wow....a lot of Q&A in this post lol. Let me see...

1. As your buffing the backing plate will always get warm, as its a mechanical reaction. Now since what you described...ruined a white pad I will go ahead an assume its a Lake Country White Pad. This is a common problem with their pads. The adhesive they use heats up along with the backing plate and after a few uses or after a few straight uses on one car using probably to much pressure, will actually melt the inside of a pad. From the outside your pad will look concaved. Its ruined, cut it in half and you will see the melted middle.

Now a good tip is if your using your PC a lot, its generally smart to replace the buffing pad every 2-3 panels, pending the amount of product you are using. Sometimes less sometimes more. Then when you pull the pad, if the backing plate is extremely hot, you probably have been using a lot of pressure and should let the backing plate cool down for 10 minutes or so. Or until its cooled. I will refer to more pressure at a later question.

2. Sounds like a bad backing plate. I would just call the company you purchased it from and get to send you a new one. I have actually heard of packing plates just coming apart. But I am curious as to where it tore at. Generally the holding screw int he middle just sheers off.

For pressure, the most pressure you want to do, which is referred to as the KB Method, is 15lbs movin slowly. If your trying to push the PC through the panel...then yes your using way to much pressure. You generally want to start with more pressure to work the product into the paint and do your cutting. Then after a few passes slowy back off on the pressure to finish the product out. As when your applying pressure you would be causing micro marring. Work back on the pressure and kinda polish out the paint.

3. Speed 6 on a PC is 6000 OPMs or pretty much around 700 RPMs. Its not really that fast. I use Speed 6 on my Griots all the time. I would refer back to the too much pressure I mentioned earlier.

For the polish, you generally only need to make and 5" line of product on the pad starting out to prime it. Then afterwards 3 dimed sized spots on the pad will be enough. Remember, polishes and compounds on a DA always migrate towards the middle of the pad as your work. So when your applying product in dots to the pad as you work always try to keep them half way between the middle and the outside edge to avoid slinging.

4. Unless your using a 4" backing plate with 6.5" pads, it wont cause a problem. The pad that came with the kit is probably a 5.5 or 6" backing plate.

 

[S04T]

Tons of info, thank you very much!! I know I didnt specify, but the pads are Lake and you pretty much described the problem with the first pad to a T. I will post some pictures of the old backing plate and maybe that will give some of you experts a little more insight into what I am doing wrong, but thank you again for your advice :beer:

 

[oldmodman]

I have the same polisher and I am using Meguiar's backing plates. I bought two so I would have a spare and I am still on the first one. I've used it for several hundred hours with 5.5 inch pads and they have gotten very warm during use. But no failures. I also have a Flex with forced rotation and I have used 6.5 inch pads on it at it's top speed. And no failures with it either.
Just try a different brand of backing plate, or even the smaller 5.5 inch pads.

 

[BLK_03]

I've been through this before. I found that the Lake Country pads are in fact some of the best. However, the backing plate I was using, wasn't meant for that pad, and the hook/loop fasteners were a little different, so there wasn't a solid attachment between pad and plate. As a result, the two would slip when the PC was cranked up. Continual slip/bite, slip/bite creates a TON of friction, and the pads/adhesive heat up and break down. It got to the point where if I even BARELY pulled the pad off the car's surface with the PC on, the pad would sling across the garage.

Once I got a quality Lake Country backing plate, the issue was gone.