PC backing plate question

virgo_888

New member
With a PC, whats the difference between a 5inch and 6inch Hook & Loop Flexible Backing Plate. THe can both be used with 6.5 pads. what's the real difference? Which one os the correct one?
 
virgo_888 said:
With a PC, whats the difference between a 5inch and 6inch Hook & Loop Flexible Backing Plate.



1"



virgo_888 said:
THe can both be used with 6.5 pads. what's the real difference? Which one os the correct one?



Depends on the pad manufacturer.

Like sonus DAS pads are indented for a 5" BP.
 
Coupe said:
1"







Depends on the pad manufacturer.

Like sonus DAS pads are indented for a 5" BP.





i know the difference is 1 inch.. lol..





i will use mostly LC pads.. maybe some meguairs. Is there a backign that i can use with most pads?
 
I really dont know for sure what the correct specs are for pads and BP's.



I have a 5" BP for my sonus DAS pads and a 6" BP for the sonus SFX pads. I havent used any other pads to know for sure.
 
I think alot of people who detail for a living have a wide range of sizes of pads and BP's.



Ya know its a good question ya have, i wonder if there is a *safe* rule/standard size for pads and BP's. If i wanted to switch to a different pad maunfacturer how would i know if i had the right sized BP's?



Im hoping some pro's will step in and let us know.
 
If you're going to use 6.5" pads then use a 6" BP. You'll have 1/4" overhang on both sides to protect you from accidentally hitting the BP on the car, and you'll have the most even pressure across the pad. If you use a 5" BP on a 6.5" pad, you wouldn't get very even pressure across the pad and you might as well use a 5" pad at that point. My $.02, but what the hell do I know?
 
I used a 5" bp with the 6.5" LC pads and it worked fine. I'm sure you get even pressure, it's just that you have an inch of pad sticking out past the bp, and when you put pressure on it that edge doesn't get compressed. So it's basically like you are using a 5" pad. The reason I like it though is that with that extra little bit sticking over the edge you can get into odd ridges better. For example the center of my car's hood is sunk lower than the outside, and has a slanted offset, or drop off.



It looks like this, but not so steep:

___

.......\

.........\____



When I polished next to that edge, I was able to also polish that slanted edge with the inch of pad that was sticking out as I was polishing the flat surface because that inch was free to conform to the slant. Hopefully that makes sense to you.
 
My six inch bp tore my 6.5 inch megs pad. It started to tear very slight from polishing the edges. So I ordered a megs one. Still waiting for it though. Sucks, the pad was used 1 time.



Although the tear is slight I am afraid it will go all the way through.
 
The one thing you don't want is for the BP to extend past the Velcro backing on the pad or it can cut into the foam. I use a 5" BP with pads ranging from 6/6.5" up to about 7" (Propel) with no issues to date. The 5" BP insures that I don't extend past the Velcro on any pad that I use, since my MEG's pads have about a 5.25" Velcro backing diameter. That isn't so much of an issue now with the newer LC pads, but a couple of years ago a 6" BP would extend past the Velcro on the older LC's that had a Velcro diameter of 12.5 cm or right about 5".



I would recommend that you also pick up a 3.5" BP to use with 4" pads...... the 4" pads do a much better job at correcting tough defects with a PC because they won't bog down as easily as the larger pads.



I also think it's a good idea to have a spare BP just in case the one you're using fails. Nothing worse than having a "detail day" ruined because you have to wait for another BP to arrive.
 
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