Group assignment:
Review the safety data sheets for each of your molding and casting materials, then make and compare test casts with each of them
List of plastics we have in our FabLab
| Name | Shore Hardness | Pot time | |
|---|---|---|---|
| Biresin G26 | 70D | 3-4 min | 100A:100B |
| Smooth-Cast 60D | 60D | 5 min | 1А:1В |
Silicons:
| Name | Shore Hardness | Pot time | |
|---|---|---|---|
| ToolDecor T20 137 | 10A | 60 min | 100А:4В |
| Smooth-on Mold Star 15 Slow | 15A | 50 min | 1A:1B |
| Smooth-on Mold Star 16 Fast | 16A | 6 min | 1A:1B |
https://www.smooth-on.com/support/faq/138/ :
Shore Hardness becomes an important factor when considering which mold rubber you should choose for making a mold of your original. For example, you would not chose a rubber with a durometer of 70A to make a mold of a plaster standing ballerina with thin, protruding arms bent at opposing angles. A 70A rubber (as hard as a car tire) is stiff and would not offer enough flexibility to extract this model without breaking it. A better choice would be a Shore 30A rubber or softer that would offer enough flexibility to easily extract the model.
Shore Durometers of Common Materials Material Durometer Scale Bicycle gel seat 15–30 OO Chewing gum 20 OO Sorbothane 30–70 OO Rubber band 25 A Door seal 55 A Automotive tire tread 70 A Soft wheels of roller skates and skateboard 78 A Hydraulic O-ring 70–90 A Hard wheels of roller skates and skateboard 98 A Ebonite rubber 100 A Solid truck tires 50 D Hard hat (typically HDPE) 75 D Cast urethane plastic 80 D
I designed model of my custom jewelry in Tinkercad:
