Skip to content

Molding and Casting

We reviewed the safety datasheets of the products used and then test and compare it !

Chose the molding material

I first wanted to take the OOMOO 25 Smooth-On material because it’s simple to use, you just have to mix the same volume quantity of the two fluids, mix it, pour it slowly in the mold and wait only 75 min. Unfortunately our Oomoo was rigid even if it was new. I think it’s probably because of the temperature storage wich should be around 20°C, but during the summer, the temperature storage room is way higher…

Here is the Smooth On Safety datasheet.pdf. This product is a Silicone Elastomer.

Thus, I chose to use the Esprit Composite Alimentary Silicone 3428 because the cure time is 15 hours at 20°C and furthermore it’s compatible with food and biocompatible. You have a base called “A” and a catalyser called “B”. You have to put 100g of “A” for 10g of “B”. It’s a “two-component silicone elastomer crosslinking by polyaddition reaction. The Vulcanization takes place at room temperature but can be accelerated by heat.” The silicon is no irritant or skin sensitizer. The product meet standardization requirements in several countries, in particular those of Class I medical devices as in European Directive 93/42/EEC or those of Class VI of the American Pharmacopoeia.

Esprit Composite

  • First estimate the volume of my mold by filling it with water :

  • Weigh the quantity of A and B I had to put to fill that volume by respecting the “A” and “B” recommended proportions (100 A for 10B).

  • Mix it and put the mixture in the air depression pump to remove the air bubles :

  • Pour the mix slowly into your wax mold to completely fill it :
  • Put it into the air depression pump another time to remove the last bubles :

Then you have to wait 16 hours for the mold to be created :

When it’s ready, demold it carefully :

Filling the mold

I chose the polyurethane 78B resin from Esprit Composite and I added some golden powder !

  • Take the same volume of the 2 products
  • Add 10% of the Golden powder !
  • Mix it until it gets warm
  • Pour it slowly into your mold :
  • Wait 15 minutes for the mold to get solid

  • Demold it

I did it again without the golden powder :

Make sure you work with the correct security equipment :

Safety measures

  • Wear gloves, eyeglasses and chemistry coat to protect you when handling some dangerous chemical substances
  • Work under a suction hood when manipulating a product with a dangerous inhalation