Excessive pad heat? What did I do?

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meanstrk

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I am trying to figure out exactly what is going on here. I am using the Porter Cable 7424XP with 5" pad and Lake Country 5.5" pads. I just finished detailing a 1984 Mercedes Benz last night but destroyed 3 pads (Two orange and one white) in the process, and am trying to figure out what is happening. It seems that the foam in the pads in degrading beginning in the center and there is massive heat being generated on the mounting base itself. One pad actually melted while the mount pad also began melting. Alkl pads are dished in the center and are not of a uniform firmness through the pad.

My question here is: What is going on? Are the pads just breaking down or is there heat being generated from the buffer itself that is causing the premature breakdown? I have never seen this kind of degradation before. This was probably the 4th car these pads have seen, so I am sure they were due for replacement anyway.

Materiels being used: Blackfire compound on orange pads
Blackfire Polish on white pad

Speed set to wide open on the Porter Cable
Average size area being worked is approx 2' X 2'

I do not apply much down force pressure at all and tend to just let the machine and compound do the work..

Just trying to get some feedback to see if or what I need to change...

DSCF5185.jpg


DSCF5184.jpg


DSCF5187.jpg
 
Looks like you should change backing plates. It doesn't look like it is cooling enough. I would suggest the 5" Meguiar's backing plate.
 
Sometimes that happens when the pad gets saturated in the middle and conducts heat more readily. Probably that single-stage you were buffing was also draggy which heats things up more. You need to change pads more often.
 
I hope you quit polishing before that big hole appeared

And I agree with what Setec said

* Edit Just noticed that was the backside of you pad with the hole (I'm very sleepy) :o

Good Night Everyone :dig:
 
I can only imagine something is wrong with the polisher. I am at a loss is to how that could happen any other way with a PC.
 
hmmm, too much speed maybe.....

I have not gone over speed 5 on my G100 and never had a problem like that. I use the Meg's 4.75 (I think) backing plate and never had a problem.
 
meanstrk said:
My question here is: What is going on? Are the pads just breaking down or is there heat being generated from the buffer itself that is causing the premature breakdown?
Click to expand...


The pictures answer your question, "yes" you created excessive pad heat.


Heat is a by-product of pressure over time plus the oscillating/rotating action of the tool. As the pad becomes wet with product the wetness holds the heat in and accelerates the problem.




meanstrk said:
Speed set to wide open on the Porter Cable
Average size area being worked is approx 2' X 2'
Click to expand...


2' by 2' is a pretty large are to work at one time if you're removing swirls or other below surface defects.


meanstrk said:
I do not apply much down force pressure at all and tend to just let the machine and compound do the work..
Click to expand...

That kind of damage comes from heat and heat comes from pressure over time. Maybe tackle smaller sections at a time and as brought up by others, clean you pad more often.


How to clean your foam pad on the fly


Never hurts to have lots of pads....



:)
 
Wow I've never seen something like that before the question I have and this is just for knowledge could you actually feel the heat that was being produced either by the machine or the pad while you were correcting the paint .
 
Do you have the fiber washer on your backing plate?

It looks like heat is may be coming from where the backing plate is attached to the machine.
 
meanstrk said:
This was probably the 4th car these pads have seen, so I am sure they were due for replacement anyway.
Click to expand...

I think you just answered your question right there. Keep in mind, these pads are made of foam and aren't going to last forever. It's not a memory foam pillow that your head rests on, it's a piece of foam that's sandwiched between a panel and a power tool that's operating at high speeds while abrasive particles level the paint. :props:
 
Harleyguy said:
Wow I've never seen something like that before the question I have and this is just for knowledge could you actually feel the heat that was being produced either by the machine or the pad while you were correcting the paint .
Click to expand...

SilverRebel said:
Do you have the fiber washer on your backing plate?

It looks like heat is may be coming from where the backing plate is attached to the machine.
Click to expand...

Haven't you guys ever melted a backing plate before? The heat isn't coming from the machine (although that doesn't help things, neither do high ambient temperatures). It's from the friction of the pad against the paint, and it depends on the pad, the paint, the polish, and the pressure, coupled with pad saturation and duration. Depending, it might be heat coming from the pad/paint interface, or from the velcro interface as the pad changes direction during oscillation.
 
Setec,

I was just asking. I saw something on another post about making sure that the washer was installed between the backing plate and machine. I didn't know if not having it could cause a heating problem or not. I have not melted a backing plate before, so this was something new I had not seen.
 
SilverRebel said:
I was just asking. I saw something on another post about making sure that the washer was installed between the backing plate and machine. I didn't know if not having it could cause a heating problem or not. I have not melted a backing plate before, so this was something new I had not seen.
Click to expand...

Sorry, I'm sure that washer limits the heat transfer somewhat, but it's really there to keep the backing plate from rubbing on the housing and/or to give you enough room to get the wrench in.

The backing plates are a lot better now, and I've never melted a yellow (LC) one, but Meg's used to have a red/white one years ago that everyone used to melt by either exceeding 4.5 or using a burgundy pad. Mike Phillips used to spend a lot of time on MOL "yelling" at guys like me for doing those things, which were outside of the Meg's recommended operating envelope for that backing plate. That kind of stuff doesn't happen much anymore, but it still happens, as evidenced by this thread.
 
Another thing in addition to what's already been mentioned is to check and see if your backing plate was installed with the cardboard washer(s). If not, something could be rubbing and generating excess heat.
 
From the responses, it seems that saturation and age are the primary culprits. I do know that the pads were getting pretty saturated and wet to the touch. I will check out the terry cloth towel methiod and see how that works. Getting an A6 dropped off today.....

I am still pretty new to this type of detailing (I was old school for years) and appreciate the experienced responses.
 
If you are doing this for money you should invest in some more pads (or a pad cleaner) so that when your pad gets saturated you can change to a fresh one. You might also consider more aggressive polishes so you don't have to spend so much time dwelling to get the results you are looking for. I'm certainly no expert, but sometimes a fine wool or a cutting (foam) pad is best on old single stage where a lot of paint is coming off. Last single-stage I did I used my old Meg's burgundy cutting pads.
 
Yep. That one is already taken care of. More pads and different compounds are on order now. I think I will order some additional pads to have in stock as well.

This Benz I just finished has original laquer paint and was a total mess. I found myself wishing I had some more abrasive cutting material, but that's a fine line as well since some parts of this car already had the clear worn through. The owner was ecstatic when he picked it up still, so that's what counts, right?
 
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