I have been sculpting heads lately for masks and I decided that, as a break, I'd sculpt something I've always materially desired, to own a Buddha Statue (I'm definitely aware of the irony of this).
So, I'll try and explain and show some pictures of how I did it. Although I am making this instructable, you can also check it out on my blog, "Make It With Jason."
In this photo, you can see the final stone casting from the mold of my original clay sculpture.
Next step will go over the sculpting in detail.
Step 1: Sculpting the Buddha Statue in Clay
For clay, I use plasticine clay, which is a firm oil-based clay that won't dry out. Since I have to work on it in multiple stages because of its complexity and my dayjob, I wanted clay that would retain its detail and not crack, and this clay has the added benefit of being reusable after the mold is made. Since it was going to be made into a mold for multiple castings, this clay is perfect for removing because of its pliability and softness.
First thing I did was load a bunch of clay all over the plaster armature in a roughly humanoid shape. I wanted a serene almost-androgynous look to Buddha. The first photo is his first incarnation, no pun intended. I stupidly ran out of clay for his arms and ears.
I decided that this one wasn't "right," so I re-did some of his features--made his eyes more appealing, decreased the size of his nose, and added some arms and hands with blue-colored plasticine.
I really liked this look a lot better, but I didn't have his hair spikes, and I wanted a consistency to them. Unfortunately, I don't have photos of what I did to make those, but I can explain it:
- first, I sculpted one of the hair spikes in clay (made it look kind of like a tiny Hershey's kiss)
- next, I mixed up some plaster and poured it over the kiss shape--completely covering it, this created a "push-mold"
- after the plaster set, I removed the clay and added some PAM cooking spray as a release agent
- then, I set out pushing clumps of clay into it and removing them and sticking them onto the sculpture's head (last photo)
Step 2: Making a Mold of a Buddha Sculpture
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!
Step 3: Pouring Concrete or Plaster Into the Buddha Mold
To me, this is the most fun part next to sculpting! Why? Because you are on the last step toward having a replica of your original sculpture and it will be literally "set in stone."
For this Buddha statue, I tip the mold upside down and add a little soap and water to it to act as a release agent. Ratio is roughly 10 water to 1 dish soap. Pour it inside the mold and work it around until everywhere is coated, then pour out. There will be a release residue that will help the cast pop out easier.
Next, I mix up some ultracal plaster stone or some concrete (no aggregate stones, just sand and cement with some acrylic fortifier added). Pour into the mold in steps and rotate and vibrate the mold as best you can to get out air bubbles and get it into all the nooks and crannies.
Vibrate a little bit more for the concrete. Be careful not to get too much water into the concrete mixture, or it won't be as strong.
The plaster can be removed from the mold in a few hours--it will steam and be hot to the touch because of the exothermic reaction to it curing. Be careful!
The concrete should be covered with plastic and allowed to cure for at least two days before removing. Concrete gets harder and stronger with each day it cures, but is much more fragile in de-molding if you don't give it time. Trust me.
Time to look at the final products!
Step 4: Plaster and Concrete Buddha Statues
When I pulled my first stone cast out of my mold, BOYOHBOY! was I excited! It turned out better than I expected, and it was the culmination of approximately 30 hours of work.
The first photo is my first cast.
The concrete cast came from the same mold, but I pulled it out a bit too early and I noticed that, because of its thicker consistency going into the mold, it did not pick up as many of the details. Despite this, I REALLY like how it turned out as well. It looks like it was unearthed from a 2,000 year old excavation, and I was very happy with this Bob-Ross-termed "Happy Accident."
> To read more about this or my other projects, go to Make It With Jason.