16. Molding and Casting

This group assignment consisted in reviewing the safety data sheets for each of the molding and casting materials we chose, and then making and comparing test casts with each of them.

Here are the molding and casting materials we tested:

Test casts

For the first test, we used a silicone (Elite Double 32) which base and catalyst are mixed in the same weight ratio.

As one can see on the bottle or on the datasheet, the working time was about 10 minutes and the total setting time was 20 minutes. After mixing 20 g of each of the two components, we poured the mixture in a Petri dish. As expected the total setting time was about 20 minutes, i.e. the silicone was ready to be removed from its Petri dish. This is a quite short time in comparison with other products.

The product we used next is a polyurethane rubber (Xencast PX60) which working time is around 10 minutes while the curing time is much longer: from 1 to 2 hours.

As well as we did with the first test, we mixed both components of the product by respecting the mix ratio of 1:1 and we poured the mixture in a Petri dish. Once again, no surprise, the working time and curing time were not different to the one given by the datasheet of the product.