Wooden soap molds are no longer the only option for soap makers these days. The choices have vastly improved as the craft has become more and more popular.
In all honesty, you can pretty much use anything as long as it doesn't leak, doesn't react with the soap and you can get the soap out of it later. Milk cartons have housed many a batch of soap for the beginner soap maker.
Aside from the usual wooden box, the usual options include silicone molds, acrylic molds, HDPE molds and plastic molds.
Some of the fancier models have removable dividers to separate the slab into pre-cut bars while others have collapsible sides to make soap removal ultra-easy.
Whether you choose to use wooden soap molds or any of the other type, you'll find your options are numerous as well as varied when it comes to price.
I have a few different soap molds I like to use for different projects. A wooden loaf mold, a small square mold, a couple of slab molds and a few silicone molds.
If you're handy with power tools and want to know how to make soap molds, simply make a box using some scrap wood.
My wooden mold cost $3.00 to make and I'm not that handy with the power tools. It measures 6 inches square on the inside and is 3 inches high.
This size will make about 10 bars of soap (110 - 150 grams each). If you plan on selling your soap, you will probably want to make a bigger box.
For those of you not inclined to use power tools, there are many soap making molds for sale on-line and they come in a multitude of shapes and sizes.
Silicon soap molds have become quite popular for a couple of reasons.
One, you do not have to line the mold which is a BIG bonus. Two, they come in many wonderful and unique shapes and sizes enabling you to get really creative.
Try using the ice cube trays to make fun soap embeds or make a soap cake using one of the great bundt pans.
Here are a few examples of silicon molds that are available.
Another great option is to make round soap towers.
This can be achieved by making soap in PVC piping. Simply buy some 2" or 3" PVC piping and end caps from your local hardware store.
Not sure how much soap will fit in your mold? Here is a formula that will calculate how much oil you need in your soap recipe to make the right size soaps. Make sure to measure your mold in INCHES.
Length of mold x Width of mold x Height of soap x .40 = ounces of oil needed
My mold is 6" x 6" and I pour my soap to 2.25" high so the calculation will be:
6" x 6" x 2.25" x .40 = 32.4 ounces
Since I like working in grams, I convert the ounces over by multiplying the ounces by 28.375. (There are 28.375 grams in an ounce)
32.4 ounces x 28.375 = 919.35 grams
(I use 900 grams in my recipes for simplicity)
This same method as above can be applied to cylinder molds with the following formula:
pi(3.14) x radius squared x height of pour x .40 = ounces of oil needed
Using a 3" pipe and pouring to 12" high, the calculation will be:
3.14 x 1.5" x 1.5" x 12" x .40 = 33.9 ounces
If you're using grams:
33.9 ounces x 28.375 = 961.9 grams