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.