Sunday, 9 April 2017

Lulu - The Body Mould

I have used a water based clay (potters clay) to make the clay wall to make the first part of the two part resin mould against. This must be water based clay so that it can be removed from the oil based clay used for the sculpt. I have gone up to the mid point / widest point of the body and arms and legs. For the boots I have gone  up to just below the boots. There will be undercuts for this but as it will be a hard resin mould but a soft clay sculpt this is fine. 

I have built up the clay around the body higher in places as this will use less resin. Here is a close up of how it looks around the boots.

The next stage is to make a foam board mould box around this and paint it with vaseline to make it easier to remove. 

Here are the resin supplies I've used. I am using Polycraft Easyflo 60 resin which is a polyurethane resin for the mould. 

Here is the first part of the mould complete. The clay sculpt remains in the mould which is then covered with a thin layer of vaseline put on with a brush. I have also brushed the sides of the mould in case the resin drips down the sides. I have included clay keys to help the mould fit together, to use less resin and one at the bottom to make a hole i can fit a screwdriver in to lever the mould open after casting.

The second part of the mould is now complete.

This second part of the resin mould covers the boot buttons. I have been careful to clean the moulds with water and a brush and to remove any clay from the buttons holes on the mould with a toothpic. The mould should be dry before its used. 

I have removed the sculpt from the armature, unfortunate it is ruined in the process which can't be helped. The armature has now been wrapped in heat shrink tubing to protect the wires. I have laid it in the mould to check it fits tightly at the end of the arms but has room around it for the silicone and is still in the right position.

The next stage is to wrap the armature in thin foam bandage to bulk it out. Ideally there should be around 3-5mm of silicone around the armature. The foam bandage is used to keep the puppet light and is tied on with cotton. This also gives the silicone something to adhere to. 

Here I have checked that the padding hasn't become larger than the mould by comparing to the test cast. The test cast is made without an armature in but with just a little padding and hasn't had the seams tidied up. 

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