Backing plate failed

2wookies

2wookies

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Took my new G15 for its inaugural run. LC MF pad with plenty of CarPro Clear Cut on the pad and after doing the hood I could feel how hot the machine was.

Was cruising on speed 5 minimal pressure and kept it moving, not sitting still. Went to blow out the pad and soon as the I hit the air on it the pad and Velcro from the backing plate flew off.

I know GG will make this right, but I couldn’t believe how hot it got with just doing the hood.

Backing plate by John Wilkinson, on Flickr
 
I hope they make it right for you because they didn't make it right for me with a GG6 backing plate that partly disintegrated.

I had to buy a new plate. This was a few years ago and I remain disappointed with GG's customer service.
 
What’s so frustrating is I’ve been using the same technique for years, now new machine and I smoke a backing plate?! I’ve been using a 21mm machine for years, is the smaller throw that much of a difference?
 
2wookies said:
What’s so frustrating is I’ve been using the same technique for years, now new machine and I smoke a backing plate?! I’ve been using a 21mm machine for years, is the smaller throw that much of a difference?
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15mm would get less hot than 21mm. But we’ve heard some say this machine with more power is leading to more heat. And microfiber pads definitely run hot. But maybe they didn’t really fix the BP like they say they did. You’ll get it replaced but sucks that it can happen to someone with a single machine and BP and now you can’t finish the job until they send a new one. That would make me really mad as you want to finish the job you started.
 
I really hope they send one free of charge
 
BSoares said:
15mm would get less hot than 21mm. But we’ve heard some say this machine with more power is leading to more heat. And microfiber pads definitely run hot. But maybe they didn’t really fix the BP like they say they did. You’ll get it replaced but sucks that it can happen to someone with a single machine and BP and now you can’t finish the job until they send a new one. That would make me really mad as you want to finish the job you started.
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Got lucky I still have my old G21 with 5&6” BPs
 
Sorry to hear/see this. But glad it happened as you were blowing out the pad and not working on the paint surface!

Keep us posted.
 
As much as I hate to say this, I think it may be partially my fault. I’m used to a slower/less powerful machine. The old G21 was a 900W 5k OPM unit, new one is 1100W 5300 OPMs. Is there a chance I just had a HUGE learning curve lesson? Is the speed/power that much stronger? I wasn’t even at spd 6, and only used it on the hood.
 
2wookies said:
As much as I hate to say this, I think it may be partially my fault. I’m used to a slower/less powerful machine. The old G21 was a 900W 5k OPM unit, new one is 1100W 5300 OPMs. Is there a chance I just had a HUGE learning curve lesson? Is the speed/power that much stronger? I wasn’t even at spd 6, and only used it on the hood.
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I highly doubt this.

This sounds like a manufacturing defect, not something an experienced machine user did wrong.

I'd be interested in any new update from GG about this.
 
Ask to speak to a manager if they give you crap. That's what I should've done.
 
With the new motor does this tool need to be run at speed 5? Speed 4 should have more than enough power. I don't plan to buy one but just watching the video this is what I was thinking.
 
I can't say whether that the failure is a result of you doing something wrong or a QC issue. One thing I'd suggest with long throw machines is using a pad with a center hole.

I was using a mf pad on my long throw polisher and ended up overheating the center and now it's dimpled in. First time I've ever overheated a pad in that manner.
 
This will probably sound like a slight against Griots Garage, but here's a few thoughts of mine.

AFAIK, yours is not the first post I've ready about Backing Plate failure with these new issue machines.
In all the years I've been a member here, I cannot honestly recall anyone having a Backing Plate Failure with an LC Backing Plate. If anyone else has, do feel free to chime in and correct me.

Yeah, I've heard of PC 7424 machines and others flying apart, but at the Spindle, not the Backing Plate specifically. Not unless Backing Plate installation was incorrect, missing the BP Washer, or improper maintainence of a machine or a third party backing plate on like say the Flex 3401.

All machines generate heat, but how much heat is too much to have such a failure occur?

I would assume running some crazy destructive torture test at full speed, and excessive downforce for a prolonged period of time, any and all machines might likely fail, whether they be Griots, Porter Cable, Rupes, Flex, etc.

But you weren't performing such a test, you operated the Machine in a normal correct fashion during a polishing procedure, and on only one panel, and this occurred.

I gather that the Backing Plate is unique to this machine, that one cannot simply retrofit a different brand Backing Plate (LC) correct?

Griots will likely replace your Backing Plate free of charge, but the questions I'd have is, was your backing plate an earlier design-make, and was shown to be prone to failure? Or?

And the other, is you mentioning the seeming excessive high heat of the machine itself, and with all the fancy design parameters with this new machine, such excessive heat should not be occurring, at least not under such normal usage, and in such a short time of use.

If it were me, I'd not just ask for a Backing Plate replacement, but ask to ship back the entire Machine, to let them inspect everything.
 
I wouldn't be surprised if they purposely design these plates to fail so you have to buy a new one. This was apparently the case with me and my GG6 plate
 
Bill D said:
I wouldn't be surprised if they purposely design these plates to fail so you have to buy a new one. This was apparently the case with me and my GG6 plate
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No company would intentionally design a product to fail in a few minutes usage(other than maybe GM and cheap ignition switches). In the era of social media that would be suicide.

Based on pics, it looks like the new machine has a thinner backing plate and that might play a role.
 
DUBL0WS6 said:
One thing I'd suggest with long throw machines is using a pad with a center hole.
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I was thinking about this all night! I wonder if because of the heat issue with this machine and GG pads ALL having the hole this may have been a big issue. When I was watching the live feed from them a few weeks ago they kept talking about how important that center hole was for the backing plate, I basically smothered the cooling of the machine...I really don’t want to have to buy all new MF cutting discs.

Another thought that kept me up was the spd/torque the machine is putting out now is WAY more than previous, maybe spd 4 is enough for the mow down?

Mike any thoughts?

I’ve been doing this for 7 years with similar technique, maybe I gotta readjust now with the stronger power.
 
2wookies said:
I was thinking about this all night! I wonder if because of the heat issue with this machine and GG pads ALL having the hole this may have been a big issue. When I was watching the live feed from them a few weeks ago they kept talking about how important that center hole was for the backing plate, I basically smothered the cooling of the machine...I really don’t want to have to buy all new MF cutting discs.

Another thought that kept me up was the spd/torque the machine is putting out now is WAY more than previous, maybe spd 4 is enough for the mow down?

Mike any thoughts?

I’ve been doing this for 7 years with similar technique, maybe I gotta readjust now with the stronger power.
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Maybe, and the hard thing not being able to quickly test this theory of yours, is not having another compatible Backing Plate on hand.

I would think any properly designed and built polishing machine should be able to withstand the rigors of use, and the use of full speed for an extended period of time without failing so quickly.

And I'd assume Griots put any and all of their machines through rigorous testing before they'll sign off on, and bless-finalize a particular design through their own R&D.

Not sure I seen mention of when you purchased your machine, but I assume quite recently.

I'm certain without a doubt Griots wants happy customers, and again I would speak to them, describe the problems you experienced precisely, and then go from there. Not uncommon that they'll send you a shipping label to pack it all up for a return.

It's nice that Mike P is also going above and beyond to help you personally. I suspect a favorable outcome for you.
 
I had a similar problem on my GG9 this weekend (10/10/20). I haven't had a chance to contact Griot's, but the backing plate got so hot, the pad melted to it. There's no way to undo that, the backing plate is permanently ruined. I wasn't doing anything unusual-- Blackfire One on an orange LC pad going over the hood.
 
Just got off the phone with GG, new backing plate is on its way.

Alan, gentlemen I spoke with, told me they use spd 4 for cutting and have never needed spd 6 as it’s overkill. Talked about technique and I mentioned the pads I was using didn’t have the hole, he said the polisher really needs that hole to get rid of the heat. So I’m gonna try and drill a hole I’m a pad and see how it works, probably need to punch it rather than drill....

Either way I’m very happy with the customer service as I knew I would be. Now to slow the machine a bit and see what happens.
 
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