Several years ago i built a dollhouse by Dura-Craft. The kit used a brick powder for around the foundation that seemed to be made out of real concrete. It is very water proof. I am trying to find that powder. The Magic Masonry powder that I found dissolves in water even after it sets up. I need the powder to be waterproof as it is going on an outdoor project. Without going into much detail, it is for a birdhouse that I am restoring. The original brick on the birdhouse seems to be identical to that older power I used on that Dura-Craft house many years ago. I could try to seal the Magic Masonry stuff but would really like to use the old stuff so I don't have to worry as much about all my hard work dissolving. Any help would be appreciated.