Here's an idea that kills two birds with one stone (heh...) anyways, if you are going to put it outside then you need to waterproof it. For example, after I coated my Beloved with the MM, I put three coats of Drylok (gray) over that. Drylok has the sand already in it and I had Beloved out in the Kansas elements for a solid month and no damage. Plus, with every coat of Drylok I put on, the more it took the stone-like features of the MM and made it more authentic.Maybe adding sand to the monster mud to give it a stone texture?????