A concrete mold can withstand many things. It is the most popular substance from which to make molds. It can be quite expensive, but in the long run your mold will be around for years if its not abused too much. To create a concrete mold you will first have to draw your pattern. This will be your final draft of what you wish your mold to be. While you are drawing your pattern, you will want to keep in mind how big the exact measurements of your mold will be. Do not go for a big mold if this is going to be your first time doing this.
Now that you have your mold drawn, use some foam for the basic mold and transfer your drawing to the foam. You will want to work slowly and evenly; this way your exact pattern will be drawn. Make sure you get every little detail into your foam. Once you have transferred your pattern to the foam, next you will want to mix your concrete.
When your mixing your concrete, do not pour out too much concrete for your project, its better to have too little than too much as concrete is not reusable once it has dried. Remember you can always make more.
Now that you’ve got your concrete mixed and your pattern cut out of foam you will want to very carefully begin applying concrete to the foam. Work slowly and make sure that you spread it evenly. Sometimes using a cement trowel will help you to even out the concrete over the mold. Make sure that you use a smaller device such as a small putty knife to get the concrete into any small lines or designs in your mold. Make sure you get your concrete over the entire mold before you move on.
Now that you have your concrete over your patterned mold, you will want to set your mold onto a surface so that it can dry. Make sure you have a stand to support it so you do not have to lay your piece on a flat surface. Now let your mold dry. Depending on how big your mold is it could take anywhere from an hour to a day or so to dry. Leave it be while it is in this process so that you do not mark up your final results.
Once it is dry you can either paint it or you can leave it, as it is gray washed. Remember to take your time and to have a lot of patience if you’re doing a big project. Maybe making another mold while your first is drying will be a good way to keep your mind occupied. Remember a watched pot never boils.