Group Assignment
Objectives
Review the safety data sheets for each of your molding and casting materials
Make and compare test casts with each of them
Materials and Safety
This week’s group assignment was to review the safety data sheets for each of the molding and casting materials at our lab, and then to make and compare test casts with each of them. In addition to the group activity, we had to individullay design a 3D mold and use it to cast parts.
The materials we have at our lab are Aditya 1010 RTV liquid silcone & Aditya Easy Cast Transparent Epoxy Resin -33
Understanding Data Sheet Silicone Rubber
ADITYA SILICONE RUBBER RTV – 1010 is a condensation cure type Silicone Rubber. It comes in 2 parts. One is Silicone Rubber and second is Curing Agent.
DataSheet
Curing Agent is mixed into Silicone Rubber in a given ratio. (40-50 ml i 1kg of silicone)It cures at room temperature. Plaster, Resin, Epoxy Resin, Polyurethane, Wax and other resins can be casted into the cured silicone mould.
Features
Specially created Silicone Rubber to make molds of Murties, Statues, Crafts, POP Cornices, Medallions and items which have deep under cuts.
Low Viscosity
Low hardness
Easy demoulding
Can be made paste to apply with brush also
Technical Properties
Viscosity - .10000 Pi
Curing Agent / Hardener Ratio 4 %
Curing Time - 6 Hours
Colour - Milky
Understanding Data Sheet Epoxy
Easy Cast Transparent Epoxy 33 can be casted into moulds of Silicone Rubber to Create Transparent Crafts, Lockets, Jewellery and Trophies. Pigments are available to make Opaque Colour Castings. It comes in Part A and Part B.
DataSheet
Features
Low Viscosity
Transparent
No grinding or sanding after casting
Can Cure in 30 minutes if heated at 65 degree centigrade and poured
Part A 100 parts : Part B 50 parts mixing ratio
Non-Yellowing
Test Parts
Silicone
For epoxy the mixing ratio of the Silicone and the curing agent was mentioned on the pack. The ratio was 40-50ml in 1000ml of silicone i.e 4-5% of curing agent in measure amount of silicone.
First batch didn’t turn out perfect, we added about 5% of curing agent. The silicone set in about 3 minutes which is not ideal. For the next batch we decided to add a little less curing agent at about 4%.
Test Outcome
For the second test 4% was used and it worked perfect. We used syringe to add curing agent to the silicone. This helps us to add the correct weight drop by drop.
Epoxy
Ratio for epoxy was also mentioned on the pack. The Proportion for Epoxy –> 2:1 i.e. for every 2 parts of Compound A we have to add 1 part of compound B.