Can I use this to glue pond rocks to concrete on a playground

Hi there. Good question! People are always finding new ways to use our products. Even though it wasn't designed for that exact project, if you decide to try it out, let us know how it goes. We're always interested to hear innovative ways to use our products. Let us know if you have any more questions at humans@flexsealproducts.com. We're always here to help. Flex On!