I noticed this on my 6.5" and 4" white pads after using 106FA on my last detail. At first I thought it was just grit that got under the foam but it's all over both pads...I've tried getting them out with a toothbrush and I also threw them into the washing machine but I can't get rid of these dots. The orange pads that I used with SIP before this were perfectly fine, the car was carefully clay barred before hand, and I never dropped these pads on the ground... I managed to get a couple of these little spots out and they were hard...aka something I probably don't want to get on my paint. I washed the pads right afterwards so I didn't let the polish completely dry on them.
