Backing Plate Separation

**charlestek** · 05-20-2019, 07:26 PM

I had been doing some heavy polishing of the inside of one of my alloy wheels with a porter cable polisher and a 3.5 inch yellow backing plate that I got from autogeek and an orange 4 inch ccs lake country pad.

Since it is not a horizontal surface in front of me, I'm sure I was using probably too high pressure on the circular painted interior (I had curb rash fixed on this wheel, but the guy who did the repair did not mask the black painted interior
of the wheel, so there was a rough clearcoat coating that I had to sand and polish down) .

At one point the urethane of the backing plate separated and it spun off the metal arbor plate. I'm not sure this was a defect or I just generated too much heat. I am planning an upcoming polish of a newish used car I bought last year and this makes me think I should have spare backing plates. Has this happened often to anyone else?

Fortunately I have a spray can of 3M #90 high strength adhesive, so I have just sprayed the metal arbor plate and the urethane interior of the pad and bonded them back together. Going to try in a few minutes.

That 3M adhesive is so strong, I've accidentally gotten it on a tile floor and had to chip it off with a sharp scraper that was barely making a dent in it. 3M sells a very expensive adhesive remover for this stuff.
Normal chemicals do not seem to touch 3M #90.

Thanks,

Phil

**charlestek** · 05-20-2019, 07:41 PM

Well, I tried, but it looks like 3M #90 does not bond well to urethane foam. I manged to put a coupe of sharp nicks in the paint/alloy metal from the fiberglass disk riveted to the metal arbor plate. Ouch. Good thing this is the
inside of an alloy wheel. Backing plate is now in the trash.

**custmsprty** · 05-20-2019, 07:52 PM

I knew that 3M #90 wouldn't cut it. It's not designed for that type of application. You would need a permanent high temp epoxy and a new clean surface to bond to. I sold 3M Packaging and Adhesives, tapes, masking, VHB tape etc for 25 years. Buy a new BP. On a sepaerate note try a drill and a mothers power ball, that's what I use for all my heavy wheel issues. But I don't use polishes on, just metal cleaners. Beware of splatter if you use it for that.

**charlestek** · 05-20-2019, 08:34 PM

cmstmsprty,

Yeah, I was just trying to finish the job since I used a new 4 inch orange pad for the only highly abrasive polish I have - Meguiars ultimate polish. Well, actually I have some Meguairs 105, but I want to save that for good stuff. I have some Meguiars medium cut polish and fine cut polish as well. However, I never before had a need to sand and polish anything on a car exterior paint and this was different anyway. This mess is a first time experience. I only have this stuff to work on my own car, I'm not a professional detailer. I sanded by hand, #600, #1000, #1500, #3000 and #5000 trizact and the clearcoat would not look as clear as I'd like. Although I bet the guy that did the curb repair who had to use a CNC lathe for the metal spokes of the wheel, should be shot. Since he oversprayed clear without masking on the inside, I have no idea if the inside was even clean at the time. I was trying to used Meguiars Ultimate Polish then followed with Menzerna Power Finish. Trouble is I initially started with a blue pad because I forgot to look up what color was used for heavy polishing. So I only had a couple extra orange ccs' in 4 inch, and after i realized the blue was wrong, I switched to orange.
I only use one pad per type of polish and save the pad for only use with the same polish. I do have a couple of 5.5 inch orange ccs's and the 5 inch backing plate, but I did not want to waste another orange pad. The other issue was that I removed the handle from the porter cable as this made it easier to fit the polisher inside the 19 inch wheel without hitting the handle, but this also caused me to freehand the polisher without fine control over pressure. I should have kept the handle on and just moved my body around the circumference of the tire.

I had originally intended to IP, clay and mild polish the wheels and seal with opti gloss coat, since I have my winter wheels and tires still on the car in May! But when this guy did the front facing repair ( and the curbing was not too extensive anyway), yanked off the rectangular strip of alloy wheel weights and told me after the job that I have to rebalance the wheel. But with the inner surface of the wheel being rough from overspray, you can't reliable stick alloy wheel weights on the inside like before, so I needed to polish the inside down anyway for being able to use weights.

**PaulMys** · 05-20-2019, 08:37 PM

Originally Posted by custmsprty

I knew that 3M #90 wouldn't cut it. It's not designed for that type of application. You would need a permanent high temp epoxy and a new clean surface to bond to. I sold 3M Packaging and Adhesives, tapes, masking, VHB tape etc for 25 years. Buy a new BP. On a sepaerate note try a drill and a mothers power bal, that's what I use for all my heavy wheel issues. But I don't use polishes on, just metal cleaners. Beware of splatter if you use it for that.

And, by the time you use the 3M products, with the time/cost of product involved, you could just get a new BP.

Also, heed Mark's advice on the Power Ball, or similar. I can't even imagine trying to use a 3" polisher on wheels. Just the thought of repositioning it 10,000 times to get every angle makes me want to visit the emergency room.

**dlc95** · 05-20-2019, 08:38 PM

Yep, I like to carry extra plates with me. I have about a dozen or so at home.

**charlestek** · 05-20-2019, 08:49 PM

dllc95,
One should always be prepared for the unexpected. Until today, I never thought about the backplate failing. And I do not make money detailing, I spend too much of the little money I have on trying to just keep my car in shape.
PaulMys, the 3M attempt was only to try to finish the job that got interrupted. I am going to order a new 3.5 inch plate and a spare 5 inch, but it takes days to get them shipped to me. I need to have the wheel/tire balanced tomorrow so I can
then put the summer tires on the car so I can drive across state to see my elderly mom. I am running new Bridgestone Blizzacks on the winter wheels, and they should not be used in these kinds of temperatures, although up till yesterday it was cold and freezing and raining in Boston. We had a all timerecord of more than 20 successive days rain in April, and even today, we are running a new record for successive days of rain for May.

**charlestek** · 05-20-2019, 08:56 PM

cmstmsprty,

You are right, I should play powerball and buy plenty of tickets each day. If I won, then I can have one of you guys polish and seal my wheels and my car, and I can sit on my sofa and watch TV!

**custmsprty** · 05-20-2019, 08:57 PM

Originally Posted by charlestek

dllc95,
One should always be prepared for the unexpected. Until today, I never thought about the backplate failing. And I do not make money detailing, I spend too much of the little money I have on trying to just keep my car in shape.
PaulMys, the 3M attempt was only to try to finish the job that got interrupted. I am going to order a new 3.5 inch plate and a spare 5 inch, but it takes days to get them shipped to me. I need to have the wheel/tire balanced tomorrow so I can
then put the summer tires on the car so I can drive across state to see my elderly mom. I am running new Bridgestone Blizzacks on the winter wheels, and they should not be used in these kinds of temperatures, although up till yesterday it was cold and freezing and raining in Boston. We had a all timerecord of more than 20 successive days rain in April, and even today, we are running a new record for successive days of rain for May.

It was cold and freezing in the beggining of July the last time I visited Boston 30 years or so ago, and if I recall it was the last time I visited Boston! I flew up from Jersey to get a paasport, it was high 80's in NYC and 65 in Boston. My mom grew up there and I was like lets get the h outa here. Hence why I live in Florida. It'll be high 90's here for the next week.

Go Tampa Bay Rays LOL.

Rays 2019 salaries: The $52 million.

We should be in last place and it would be okay.

The Red Sox again have the highest payroll in baseball at just less than $222 million,
And they still had to pay Panda Sandoval $18,000,000 for that debacle. LOL

**PaulMys** · 05-20-2019, 09:01 PM

Originally Posted by charlestek

dllc95,
One should always be prepared for the unexpected. Until today, I never thought about the backplate failing. And I do not make money detailing, I spend too much of the little money I have on trying to just keep my car in shape.
PaulMys, the 3M attempt was only to try to finish the job that got interrupted. I am going to order a new 3.5 inch plate and a spare 5 inch, but it takes days to get them shipped to me. I need to have the wheel/tire balanced tomorrow so I can
then put the summer tires on the car so I can drive across state to see my elderly mom. I am running new Bridgestone Blizzacks on the winter wheels, and they should not be used in these kinds of temperatures, although up till yesterday it was cold and freezing and raining in Boston. We had a all timerecord of more than 20 successive days rain in April, and even today, we are running a new record for successive days of rain for May.

I get it, man. And in no way was I trying to be harsh with my post.

If you ever need anything, I would be willing to forget that whole "Boston" thing as a Yankee fan.

And finally.... Man you aren't kidding. The rain has been relentless here this spring.