What in the world happened to my backing plate?

keeotee

keeotee

Detailing Stare
I was using my pc 7424 tonight on a friends jeep, and I started getting some wobbling and all of a sudden the pad came off.

So, I inspected the backing plate and it was really hot and in fact, the center area had melted, was very hot to the touch and the velcro was warping and some lesser melting occurring in some other spots on the backing plate.

I'm attaching a pic of it. Any ideas what might have caused this? I can't tell if the backing plate failed or the pc itself. Although the way it got so hot, and primarily in the center of the backing plate, I'm leaning towards the pc itself.

Any thoughts? Ideas? Suggestions as to what it might be or what is going on with this thing? It's only about 4 months old!
 
looks like the pc overheated ....do you crank it up to 6 for extended periods of time? ...return it, it has a 1 year warranty... right?
 
Steve,

I had it up to 6 for maybe 3 minutes at most. Almost always I run it at 5 or 5.5. I'm sure it does have at least a 1 year warranty. I was betting it was the pc. I couldn't imagine the backing plate being at fault in any way.

Ok, I guess I should ask this question then as a followup: does it hurt it to run it for long periods at 5 or 5.5? Isn't that the standard setting for a swirl remover?
 
well basically most people over use this machine...it is really intended for light work not the kind of work a rotary will do...it should be able to sustain the 5-5.5 speeds for a good amount of time, but mine sounds like it's ready to explode when I crank it up to 6 ....
look at it this way...you truck is capable of red lining, but would you really keep it there for too long?
 
Poorboy said:

look at it this way...you truck is capable of red lining, but would you really keep it there for too long?
Click to expand...

Just to hijack a thread with random pointless knowledge...

I have seen a Honda CRX with no oil in it whatsoever redline for 8 minutes, and then still manage to start and run for another 4 minutes before it caught fire.
 
Tassadar said:
Just to hijack a thread with random pointless knowledge...

I have seen a Honda CRX with no oil in it whatsoever redline for 8 minutes, and then still manage to start and run for another 4 minutes before it caught fire.
Click to expand...

That's hilarious.

Thanks for the laugh.

I'm not sure I agree with Poorboy tho. If a machine is designed to run at a certain speed, it should be capable of maintaining that performance for extended periods. (I'm an electrical engineer by the way - motors are my business).

However, having said that, common sense dictates that things last longer when they are taken care of.
 
I would tend to agree. While the PC sounds like it wants to barf when run at 6 it should be able to do so for extended periods without trouble. Porter Cable is a top notch tool company with a strong reputation, I doubt they would create a setting on their dial the tool couldn't handle. Motors get hot for two reasons to my knowledge (maybe more, let's ask the engineer!). A short such as if some water or other conducting material penetrated the casing, or it was overloaded such as run on 6 with very heavy pressure. Like Steve said, it's not a rotory...
 
So freedre what are you saying? I agree that things last longer when they are taken care of. Are you saying the machine wasn't taken care of, or do you have a secret to the machines maintance that you could share with all of us? I have a PC 7424, and when I turn it off after running it, the bearings make alot of noise. My PC is probably only 3 months old. If there is some maintance or lubrication points on it please let us know.
 
freedre said:
I'm not sure I agree with Poorboy tho. If a machine is designed to run at a certain speed, it should be capable of maintaining that performance for extended periods. (I'm an electrical engineer by the way - motors are my business).

However, having said that, common sense dictates that things last longer when they are taken care of.
Click to expand...

I would agree but there are other factors involved such as a rubber velcro backing plate...I believe these machines were first intended for wood work not auto finishes, and I also have seen backing plates with holes in them for attaching sand paper which would allow more cooling..

I'm not an engineer , but I did once stay at a Holiday Inn Express :lmfao
 
Just some more insight. I have spoken to Porter Cable on various occasions while designing the Edge2000 DA foam pads and have been told by their engineers that the machine is being used for and I quote "the wrong applications". The PC is really a sander for use with sandpaper very close to the orbital head of the machine. It has found a niche as a polishing tool for applying and removing wax but never was intended to compound or buff and especially not at speeds above 5. While I understand that many people use the machine for this purpose it is not surprising that the machine will break down, over heat, and wear out prematurely. Porter Cable says if you want to buff with compound they make a rotary buffer for that job. If you want your PC to last keep your speeds below 5 if you intend on using it for a buffing process, this way at least you will not beat up the machine too bad. Just my thoughts.

Aaron Krause (President & CEO)
777 Henderson Blvd.
Suites # 1 & 2
Folcroft, PA 19032
---------------------------------------
Æ’v Phone: (610) 583-4883
Æ’¢ Fax: (610) 583-4885
Æ’x Email: aaron@dedicationtodetail.com
Website: www.edgepads.com
 
I just had to return mine in for repair last week, and it forced me to buy another NEW PC. There is a weak connection in the positive/negetive when I took the housing off. It will take 4-6 weeks to be repaired. :angry

While the 7424 and the 7336 have found a niche in auto detailing, it certainly cannot handle major paint repair. This is where a rotary comes into play. Now, PC does make a 7428 rotary, but I personally like the Makita.

The moral of the story is this: Use Poorboy's and the new Edge 2000 DA pads, and use them ALOT.
 
OI812 said:
So freedre what are you saying? I agree that things last longer when they are taken care of. Are you saying the machine wasn't taken care of, or do you have a secret to the machines maintance that you could share with all of us? I have a PC 7424, and when I turn it off after running it, the bearings make alot of noise. My PC is probably only 3 months old. If there is some maintance or lubrication points on it please let us know.
Click to expand...

OUCH!

Sorry, I didn't mean to insult anyone.

No, to all of the above. I simply mean that if a machine has a setting of '5' (or 6 or a zillion) it should be able to run at that speed. It will not fail from overheating, because it has a built in sensor that will shut it off if it exceeds 60 degrees C over ambient. In other words, if you are in Southern California on a nice 30 degree C summer day, the machine will get up to 90 degrees C (almost the boiling point of water) before it will shut itself down to prevent overheating. Most people feel that if a machine is hot to the touch, it is overheated - this is not the case. For the machine, it is business as usual.

Let me say this about your particular situation tho - if your bearings are noisy - STOP USE IMMEDIATELY!! There is something wrong with the bearings and continuing to use the machine will damage it severely! Get the bearings replaced (the machine is designed for that). It "shouldn't" cost you more than $10.

I understand the manufacturer saying that the machine is being used for something for which it was not designed, but I have been in this business for more than 35 years and I don't have any sympathy for statements like that at all. To heck with that. It's a machine, dammit. If it is going to break, don't sell the darn things. Shame on you Porter Cable.
 
It's my porty and I'll cry if I want to, cry if I... oh sorry.

I bought a new one today and I'll keep the speeds at 5, maybe up to 5.5.

I would agree that if the dial says 6, it ought to do 6, but then again I had a car once where the speedo read higher than it would go!! :) I had one once where the speedo ended before the car would - loved that car.

But, I work with computers, so I wouldn't know about what the pc can and cannot do. I can say that I did not use excessive pressure as I could see that too much pressure at all would bog the thing down and not allow the full range of motion - obviously this is defeating the purpose of the machine at least in that regard..

Well, I will say this though, why doesn't dumb Porter Cable make a machine for what we use it for - I mean DUH. Are they like waiting for a market or something? Did I say DUH already!!

I figured returning it would take quite some time before I got it back, so I'm not going to wait. My order is in to Dwayne for Monday morning.

EDIT: Oh, I should add another thought to this. I have read many posts concerning the pc 7424 and so many have had theirs it seems for a very long time without trouble. I imagine I'm one of the few to perhaps get a bad one. It happens (and apparently I'm not the only one in this thread, but still...). Sometimes a bad one gets through. I've no qualms about getting another one.
 
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Hmmm... interesting. Porter-Cable claims the 7336 was not intended to be used for polishing, yet they attach a foam pad and relabel it the 7424 polisher. All this was done with the knowledge that the little bugger cannot handle the load? They never bothered to beef up the motor or change the gearing so it could handle the load? I could see Craftsman or Black and Decker pulling a stunt like this but Porter-Cable has a solid reputation which they built by NOT doing this. I am not saying you are wrong Aaron, I am just sitting here scratching my noggin' in wonderment and confusion.
Now that this little "skeleton" has come out of the closet, I see a HUGE argument for using small pads on your PC! I was using 8.5" and 7.5" monsters, perhaps we should not be exceeding 6" pads? What do you think Aaron?
 
Oh I almost forgot, there is a hook and loop backing plate with holes as Steve mentioned. You use it in conjunction with the rubber sealed dust collector attachment for sanding wood (there are 6" velcro backed sandpaper sheets you can buy with holes cut in them to match).
 
Personally, I am a bit down at the durability of my PC......I'd be saying this too even if they were a sponsor of DC. I am on my 3rd one in 2 years. The first two had the same problem, they were not getting a good connection after some time. At this point, I'd be more than willing to pay Lowes a $50 insurance policy just so that I could go to the store if it breaks and get a new one right then and there, just like Harbor Freight Tools.

I wanted to buy a similar machine by a different brand, but frankly, there isn't one that really exists. D-Walt has a similar one, but the connections are all messed up, and none will take Edge's pads.

Do the people at Porter Cable not realize that this is a niche market they fell upon? I mean, they make a Meg's PC now, so they have to know that we are using it for more than applying wax.

Sincerely,
Angry Customer :angry
 
Well, hang on a minute folks... this just in from the "TripWire Services"...

Porter Cable manual, and I quote the front cover: "

Double Insulated Random Orbit 5" Sander/6" Polisher"

On page 8, the heading of "Using the Polisher", item number 7, and I quote"

Do not mix products (wax, polish, cleaner, etc.) on the same pad. Label each pad to prevent future confusion.

Item number 8, and again I quote:

The polishing pad is designed for product application only. Remove product residue with a soft cotton towel.

Maybe I'm missing something here, but it sure sounds to me like they are talking the same talk we are, unless of course they are referring to working with wax, polish, cleaner, etc. in reference to wood and not paint. One would think they might point that out if such were the case though.

Nevertheless, I've bought another as I just don't want to be without one. I'm just hoping the next one lasts much longer than this.

Say, I'll bet we could get plenty of folks to post in this thread telling of how long they've had their pc for and how often they've used it with no problems.

I'm just not ready though to say porter cable isn't good since I believe, as I mentioned that sometimes a bad one just slips by. I don't think proter cable intends for a bad product to be made and sold. Not many companies do intend such things.
 
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