With the sculpture all ready to go, I moved on to making the mold.



This can be a complex process and maybe even take as long as your sculpture. It is a real investment, in time and money.



I decided I would use FlexPro urethane rubber to make a glove mold, and then make a mother mold in Ultracal30 plaster stone.



> If you want to see a bit more about making urethane molds, click here.



First, I dripped and brushed urethane A/B mold making solution onto my Buddha. This takes time, and a good solid 3 or 4 hours in a single stretch to do properly. The urethane goes on thin, and requires many layers build up for maximum flexibility and strength. You put each layer on BEFORE the previous layer cures fully, so it doesn't de-laminate. You can make it into a paste by adding some cabosil (fumed silica), but BE CAREFUL as it creates a cloud that is dangerous to breathe. Best to mix it outside in an area where people won't need to be. And wear a breathing mask.



Buildup the urethane enough so it is smooth on the outside--you don't want too many crevices, or the plaster will go into them and encapsulate the rubber and not be able to come apart.



Urethane and silicone make excellent molds for pouring plaster and concrete casts because they capture the original sculptural details down to a fingerprint. Keep that in mind when you sculpt--I smoothed every surface down with baby oil and a sculpting tool.



Once the urethane cured overnight, I created a two-piece plaster mold. This is a pain in the neck because plaster is messy and you need to create a clay parting line for the first half and then pour the second half once the first part is cured and cool.



I try and make my mother molds really non-detailed so they can pull away from the glove mold easily. For this, I use fiberglass mat and dip it in the plaster and add to the urethane in multiple swatch layers--much like people use burlap or plaster bandage material.



After you remove the clay parting line and spray the plaster and urethane with PAM, you are ready to add the second layer of plaster.



Once both sides of the mold were set and cured, I patiently and slowly pried them apart with a small screwdriver and wooden wedges. Take time and don't screw this up--it will be something worth doing right. Make sure to make the mold flat and bottom-heavy for when you put it on a table to pour plaster or concrete into it, so it'll stay upright.



Then, you're ready for the fun! Time to pour a casting!