One of the more enjoyable facets of building your own dungeon tiles is creating additional molds to add your own unique pieces, as well as speed construction. At the beginning, it is smartest to restrict yourself to using the molds available from Hirst Arts, but at some point you may want to branch out and customize your dungeon tiles.
Bruce Hirst encourages people to do so, while observing that creating original molds is an exacting process. So far, my mold making efforts have been confined to creating molds to speed construction.
Here is an example. I created this mold to assist in the production of my floor tiles. It yields 14 half-by-one inch edged blocks, and 7 half-by-half corner blocks.
To produce this, I needed to make a master (the original blocks are glued to this piece of 5" x 8" glass.
You'll need a frame, in order to pour the silicone over the master and keep the silicone from running off the sides. In this case, I raided the lego collection of my son and made this 4" x 6" frame.
You'll also need some silicone. As far as I can tell, this Mold Max 40 is the same silicone that Bruce Hirst uses for his Hirst Arts molds, and it sets up fairly quickly.
The goal is to produce more of the floor tiles pictured below. While I have a glut of the one-inch centre blocks, I have very few of the edge pieces, thus necessitating my mold-making effort above.