With the clay model made and properly prepped it was time to move on to the next phase of the process. If you've never made a latex mold you'll enjoy this section. In fact, if you have a few sasquatch casts laying around this can be a great technique for making copies. Then you can swap and trade casts with your friends just like collectible cards. Or sell them on E-bay. Whatever.
The first step is to prep the model with a release agent. Since I didn't want to leave the house and drop some dough on a real release agent I decided to MacGyver it. So off to the pantry I went for some Best Choice Pan Coat™ (aka ghetto PAM).
After testing to see if the Pan Coat was flammable (it is) a thorough coating was applied to the clay model.
(Nothing says scientific like generic pan coating.)
(A thorough coating of Best Choice Pan Coat means you'll never scrape another pan.)Once the clay model was coated with pan coating the excess liquid was removed with a dry paper towel (also generic).
(Don't forget to dry between your toes.)Once the extra coating was removed it was time for the latex. My personal preference is Mold Builder liquid latex by Castin' Craft™. You'll also need a paint brush to apply the latex. Be sure to prep the brush and make sure any loose fibers are removed or else they'll end up embedded in your mold.
The mold is created by applying multiple layers of liquid latex to the model. Each layer should fully cover the model and be given adequate time to dry before applying the next layer. The evenness of each layer isn't critical but if you apply too much in one area it will take longer to dry. From personal experience I like to make the first couple of layers extra thin, with subsequent layers being thicker.
(Diving in with the first layer.)
(The latex is applied thinly enough that you can still see the surface color of the model.)Once the first layer is applied it was time to sit back and wait. If the latex is applied thinly enough it shouldn't take more than about 30 minutes before you can apply the next layer. As the latex dries the color changes from white to an off-yellowish color. The below photo was taken in between the application of subsequent layers. The areas that are white are still wet and need additional time to dry.
(If it's white it ain't yet right.)
(If it's white it ain't yet right.)This is as good a place as any to point out that between coatings you need to thoroughly clean your paint brush. Warm water will work just fine but you need to be sure to remove all the water before applying the next coat.
With each subsequent layer you can increase the thickness of the latex applied but you'll need to allow an increased amount of time for drying. Since the last two layers I applied were especially thick I allowed an hour between coats. The fact that the latex changes colors makes it easy to tell when it's ready for another layer.
With each subsequent layer you can increase the thickness of the latex applied but you'll need to allow an increased amount of time for drying. Since the last two layers I applied were especially thick I allowed an hour between coats. The fact that the latex changes colors makes it easy to tell when it's ready for another layer.
(If this were a real foot I bet that would tickle.)That's about it. The total number of layers is flexible but you want to make sure you apply enough layers to prevent the mold from ripping or wearing thin. For this model I used a total of seven layers with the 6th and 7th layers being extra thick.
(The finished product.)
Once the liquid latex application is complete the latex needs adequate time to dry completely. Since I'll be creating a mother mold over the model (with the latex still in place) I'll just leave the latex where it is until I'm ready for the next step.. If you need to remove the latex from the model prior to creating a mother mold (or if you're not bothering with a mother mold) I'd allow 24 hours before removing.
That's it kiddies. The next installment will be a mother.
(The finished product.)Once the liquid latex application is complete the latex needs adequate time to dry completely. Since I'll be creating a mother mold over the model (with the latex still in place) I'll just leave the latex where it is until I'm ready for the next step.. If you need to remove the latex from the model prior to creating a mother mold (or if you're not bothering with a mother mold) I'd allow 24 hours before removing.
That's it kiddies. The next installment will be a mother.
