That is funny. I guess that I should probably use the "top side" when it rains!!! They actually were fine today in the dry. Quite handy.

FB has a great idea. I'll grab some sand out of the sandbox my dad made 20 years ago for the kids and mix it with....something.

Amazon Prime has skateboard tape, if the grit-paint mixture doesn't do the trick. You can see in the picture that serten posted that there are raised ridges that drastically reduce that surface area for the tape to stick to and work.

Thanks for all the responses.............greg