| If you are casting hypertufa, plaster or concrete | | | | doesn't stretch the water idea will work. The nice |
| in your new silicone mold you will need to build a | | | | thing about water that it is easy to take out! You |
| casing for it. If you only plan to use the mold for | | | | can take it out once you have built up to the |
| one casting you should make a simple plaster | | | | point where your plaster will support itself. Once it |
| cover. The fastest way to do this is by using | | | | is out you can finish the buildup. |
| plaster of Paris. Mix it and soak some strips of | | | | Keep in mind you will need a hole to pour the |
| cloth in it and build up over your mold. You should | | | | concrete into the mold. You will also need a base |
| go for at least ¾" thickness. Don't worry | | | | on the casing so the whole thing does not fall |
| about how it looks you will be cutting it off and | | | | over when you are pouring. Generally the casing is |
| throwing it away when you are done. | | | | set up so that you are pouring into the bottom of |
| I probably should tell you to make sure that the | | | | the mold. This means that it will be sitting |
| master is in the mold when you start. Remember | | | | upside-down. |
| that you will need to take out the master. Be | | | | I guess by now you are starting to see a little |
| sure to leave some way to do this. I can't tell you | | | | more clearly just how much work there is to |
| how because every mold is different. Sometimes | | | | making a "simple" silicone rubber/RTV mold? |
| you can get away with filling the mold with water | | | | Wait 'till you see my 'short' story about making a |
| and making your casing around it. Test this buy | | | | fiberglass supporting cover! |
| filling your mold and seeing if it stretches. If it | | | | |