Mini Show Down on 3"+ DA backing plates.
With all the recent talk about the 1" and 2" foam pads that have come out I thought I'd might do a mini show down of the current DA backing plates.
From what I have discovered there are a couple of basic widths. They are 2 7/8" and 3 1/2". Standard D/A machines use a 5/16" mounting stud.
Some of the 3" pads/discs on the market are right at 3" so it is critical that the backing plate be slightly smaller than the pad/disc you are using.
I have taken a few shots of a few of the commonly available backing plates that use a standard 5/16" mounting stud that work with a DA polisher.
Top Row Left to RightMeguiar's Professional Unigrit™ 3" Backing Plate & Adapter Kit, Dual Action 3 Inch Flexible Backing Plate and the Dual Action 3.5 Inch Flexible Backing Plate
Center Left to RightLake Country Hydro-Tech 3 x 1.25 Inch Foam Pad, Griots Garage 3 Inch Mini Red Wax Pad, CCS 4 Inch Spot Buffs Foam Pads
Bottom Row3 1/2" Carpro Flash Pad and Meguiars 3 inch DMC3 DA Microfiber Cutting Disc
Meguiar's Professional Unigrit™ 3" Backing Plate & Adapter KitThis backing plate features size 5/16-24 female thread. It is designed to be used with any of the five included adapters. Place the included washer* on the plate, then install the appropriate adapter.
Although this plate was painstakingly designed to optimize the performance of Meguiar's Unigrit™ Sanding and Foam Finishing Discs, it is an outstanding choice for use with any sanding disc or buffing pad.
To insure the 5/16" adapter stays in the backing plate I suggest using Loctite Red or Blue when you screw the adaptor into the backing plate.
Here are a few shots with the different pad/disc to show edge tolerances.
Dual Action 3 Inch Flexible Backing PlateThe 3 Inch DA Backing Plate is designed to offer perfect balance and support for 3 inch foam pads. The actual diameter is 2 7/8 inches, so the plate is recessed back from the edge of the pad slightly for safety.
A few have close tolerances but there is pad overlap.
Dual Action 3.5 Inch Flexible Backing PlateThe 3.5 inch backing plate is designed for 4 inch pads. The 3.5 inch plate has a 5/16” threaded post Lake Country 4 inch pads. Use this backing plate to correct small areas of paint or to polish particular spots.
The backing plate overlaps the edge of the pad - This is dangerous
Last but not least...the backing plate width measurements
Top To Bottom Unigrit, 3" and 3 1/2"
I just recently obtained the Meguiars Soft Buff DA Polisher 3 inch DBP3 and 5 Inch DBP5 Backing Plates.
I didn't get a chance to add the 3" to this review. It looks good and solid. 2 7/8" width solid fiberglass.
Feel free to add your experiences or to ask questions. Thanks for viewing.