I agree with Roy,,, But I use hot water and just squeeze out all the air. Dab it with a paper towel until it aint dripping then sew it on wet. Lots of stretch (Between an 1/8th & a 1/4" gap) in the leather depending on thickness. When it dries it is so tight it wont move. I don't use any glue anymore under the handle and they have not slipped.
You can thin leather down on a 4" belt sander by folding it under a scrap piece of flat wood,,, just watch the finger tips!