Choosing a Base
For many beginning soapmakers, soap casting is a desirable technique because there is no need to use caustics. The soap has been premade with a commercial version of the lye-and-oil method soapmakers use at home. The lye part has already been done for you. Once difficult to find, glycerin soap base is now readily available. You can find many varieties, along with casting supplies, at craft and large fabric stores. Clear glycerin soap from the bar-soap bins in the grocery store works well, too. You need to experiment with bases until you find the kind you like.
What to Look For
When shopping for a base, you need to have some hands-on experience so you can compare. Get some transparent bars at the grocery or one pound of each kind offered at the craft store and do some testing. You're looking for soap that melts easily, has no strong odor, isn't sticky when hardened, doesn't change color under normal conditions, and doesn't “sweat” excessively. Discoloration, stickiness, and odors can happen to good-quality soap base if it is old, has been remelted a number of times, or is exposed to excessively high temperatures. Lower-quality soap base will have these properties right out of the package or after normal use.
What is sweating?
Sweating happens as the glycerin in the soap attracts moisture from the air. Even the best bases will sweat in high humidity. Low-quality bases will sweat all the time. To prevent sweating in general, wrap your hardened casting soap projects right away and store out of high humidity.
Where to Find It
You can find high-quality casting soap at reasonable prices from many online suppliers. Shop for a good base by going to online suppliers. In the case of casting soap base, it pays to get the best base you can, and this usually means Internet mail order. However, not all bases found on the Internet are of high quality. Ask around and ask for samples or purchase small amounts.
