If you have frog spit and change to one of the custom mixes make sure you get all the frog spit off first. frog spit sticks to frog spit very well, some of the other custom mixes do not. I went to a custom mix last year and after about 20 hours of running time I noticed some small areas starting to chip off. in each spot you could still see some some of the gray color of the frog spit under the new bottom. the frog spit was sanded off, but you have to get it all completely off. If you can still see any color keep sanding, or some of the other mixes wont stick to the frog spit.