People hear that the Flexi-Felt is a great product and will stay on no matter what? They aren’t a miracle product, but they are excellent when installed properly and used as they were intended.
The first thing many people do wrong is to not clean the bottom of their chair legs properly. I’ve done myself using the products that go on windows for hanging strings of lights or Halloween decorations. I put it on without cleaning the surface and less then an hour later what I put up is on the ground. You HAVE to clean the surface properly to remove all old glue, dirt and grease. Do a final wipe with rubbing alcohol to remove any oils that may be on the surface (the products that remove old glue contains oil which will interfere with the new glue holding on). Only then can you apply adhesive pads. Let the pads set for a while so that the adhesive has time to bond with the surface.
Secondly, adhesives do not bond well with rubber and some plastic products. You can try it, but you’ll find that they don’t always stay on.
Thirdly, a little pad won’t hold onto a tiny leg or a heavy chair. The adhesive that Flexi-Felt uses is designed to take shear forces but the adhesive must have sufficient surface to adhere to in order to grip properly. Too small a surface for the forces being exerted on it and it’ll slip off. Or, just plain to much force from a heavy piece of furniture (or furniture and a person) and of course the pad will move.
Next time your pads don’t stay on you’ll know why but what’s even better is to install the pads correctly to greatly reduce them from slipping off. The other option is to purchase the Flexi-Felt Clear Sleeve floor protectors. They stay on and are especially good for small furniture legs where the adhesive felt pads don’t work well.