Bronze Resin sculpture also known as “cold cast bronze” or bonded bronze, is made of real bronze powder, mixed with resin, used for making sculptures and other artistic creations. This material allows for finer detailing and is easier to handle than traditional, high temperature cast bronze.
Here is our guide and product suggestions for your cold cast bronze sculpture additions.
We would suggest you carve from Chavant Hard Non-Sulphurated Modelling Clay. This is a hard plasticine clay which can be carved, use a heat gun or a hairdryer to soften if it the clay is too hard.
Once you have created your master then cast in a silicone box mould, we would recommend a mid-flex silicone. Tiranti RTV120 Silicone Mould Rubber and Green Catalyst Kit which comes as a 2-part kit. To create the box, we recommend Lego or foam board sealed with a hot glue gun.
The silicone sets in 24 hours then you can remove your clay master and allow the mould to air for 24 hours to allow any residual chemicals to evaporate.
The final stage is to cast your bronze, this cold cast method was developed by Tiranti in the 1950’s and uses more bronze that the modern methods to give a heavier real bronze result.
For this you will need resin Tiranti Multi-Purpose Polyester Resin, hardener Tiranti Liquid Hardener and bronze powder Tiranti Bronze Metal Filler.
The mix ration is 2% hardener to resin by weight so 50g resin needs 1g hardener then add bronze powder in the ration 1 part resin to 6 parts bronze.
So, for our 50g example you would add 300g bronze then pour into the mould and allow to set this will take up to 24 hours.
Once set the finished bronze can be polished and patinated just as you would with a bronze cast in a foundry.
There are a couple of inexpensive booklets which cover the casting and silicone moulding process which we can recommend: Tiranti the Silicone Rubber Booklet, Tiranti Polyester Resin Booklet.
