This stuff is probably a terrific product but I think the cartridge I got --although it was undated-- was past its prime; the sealant would barely come out of the spout (cut to 1/4" opening) and it took all my strength on the caulking gun to get a marble-sized lump of the stuff to come out. Some of the sealant went behind the piston end and oozed up into the rear if the cartridge-- a mess! But I was able to apply the stuff with my fingertip, and it seemed to work very well. Wow is it sticky! I don't know if the 4200 is supposed to be that viscous when it is "new", maybe I will try another cartridge of it someday but I will look for a date on it.