## Review the safety data sheets for each of your molding and casting materials,then make and compare test casts with each of them
# Author : seunghwan-ji
We tried as many material as possible to make mold and cast something like silicon, urethane resin, gypsum plaster and colorants for urethane Rubber.
And also vacuum degassing.
Every materials are from Smooth-on except gypsum plaster.
![1](img/group/week10-group/1.jpg)
# Silicone rubber
** MOLD STAR 30 **
https://www.smooth-on.com/products/mold-star-30/
Mold star 30 is blue silicone. It’s mix ratio is 1A:1B by volume.
And it’s pot life and cure time is 45minutes and 6hours each.
![2](img/group/week10-group/2.jpg)
Output was flexible and high resolution.
![3](img/group/week10-group/3.jpg)
** MOLD STAR 20T **
https://www.smooth-on.com/products/mold-star-20t/
Mold star 20T is translucent silicone. It’s mix ratio is 1A:1B by weight and volume.
And it’s pot life and cure time is 6minutes and 3-minutes each.
![4](img/group/week10-group/4.jpg)
Output was more flexible than Mold star 30. And it has high resolution too.
Here’s the Safety data sheet for these two materials.
https://www.smooth-on.com/msds/files/BD_DS_Eco_Equ_EZB_EZS_Psy_MS_OOMOO_Reb_ST_SS_Soma_Sol_Sorta.pdf
Safety - Use in a properly ventilated area (“room size” ventilation).
Wear safety glasses, long sleeves and rubber gloves to minimize contamination risk.
Wear vinyl gloves only. Latex gloves will inhibit the cure of the rubber.
Store and use material at room temperature (73°F/23°C).
Warmer temperatures will drastically reduce working time and cure time.
Storing material at warmer temperatures will also reduce the usable shelf life of unused material.
These products have a limited shelf life and should be used as soon as possible.
![5](img/group/week10-group/5.jpg)
![6](img/group/week10-group/6.jpg)
![7](img/group/week10-group/7.jpg)
![8](img/group/week10-group/8.jpg)
# Vacuum degassing
Degassing is advantageous for high quality of casting material removing bubble inside the material.
But it can’t be done if material’s pot time is short.
So we tried vacuum degassing on Mold star 30 that has 45minutes pot life.
After mixing 2 parts and mix with wood stick thoroughly, put mixed material cup inside the degassing machine.
Then, turn the lever to make vacuum.
Material will be bulge up removing bubbles.
Degassing until material shrink, then we can get degassed material.
![9](img/group/week10-group/9.jpg)
# Flexible urethane foam
** FLEX-FOAM IT-X **
https://www.smooth-on.com/products/flexfoam-it-x/
FLEX-FOAM IT-X is white flexible urethane foam that expand 6times after mixing.
It’s mix ratio is 1A:1B by volume and 105A:100B by weight.
And it’s pot life and cure time is 50seconds and 2hours each.
It is porous material because it expand to make more hard surface we should give pressure to mold.
![10](img/group/week10-group/10.jpg)
It expands 6 times by volume but it was difficult to calculate the adequate amount of mixture.
First trial was almost half of the mold. But it expands little bit.
Here’s the Safety data sheet.
https://www.smooth-on.com/msds/files/Flex_Foam-It_Series.pdf
![11](img/group/week10-group/11.jpg)
** FLEX-FOAM IT-X with So-STRONG **
https://www.smooth-on.com/products/so-strong/
So-STRONG is liquid urethane colorants. We can put this ratio of between 0.01% - 3% of the total weight (Parts A + B mixed) of the material being cast.
Seunghwan tried yellow and green tint to make light green.
![12](img/group/week10-group/12.jpg)
![13](img/group/week10-group/13.jpg)
![14](img/group/week10-group/14.jpg)
In this case, Seunghwan put generous amount of material and it expanded well.
It has little flexible and sticky surface.
Here’s the Safety data sheet.
https://www.smooth-on.com/msds/files/SO-Strong.pdf
![15](img/group/week10-group/15.jpg)
# Urethane
** TASK-16 **
https://www.smooth-on.com/products/task-16/
This material is light yellow color urethane that has little elasticity.
It’s mix ratio is 1A:2B by weight. And it’s pot life and cure time is 6minutes and 24hours each.
![16](img/group/week10-group/16.jpg)
On the data sheet, it says the color of material is light yellow.
But the material Seunghwan used was almost brown.
But it cured well. It has hard surface and high resolution.
![17](img/group/week10-group/17.jpg)
** TASK-13 **
https://www.smooth-on.com/products/task-13/
This material is black color porous urethane that has little elasticity also.
It’s mix ratio is 100A:120B by weight.
And it’s pot life and cure time is 3minutes and 20minutes each.
![18](img/group/week10-group/18.jpg)
Output was fine at the surface that contacts with the mold.
But side and top part have porous surface. And it has slight flexibility.
Here’s the Safety data sheet for these two materials.
https://www.smooth-on.com/msds/files/TASK_13_14.pdf
Materials should be stored and used in a warm environment (73°F/23°C).
These products have a limited shelf life and should be used as soon as possible.
All liquid urethanes are moisture sensitive and will absorb atmospheric moisture.
Mixing tools and containers should be clean and made of metal, glass or plastic.
Mixing should be done in a well-ventilated area. Wear safety glasses, long sleeves and rubber gloves to minimize contamination risk.
![19](img/group/week10-group/19.jpg)
# Gypsum plaster
** Reinforced plaster L type **
Here’s the Safety data sheet
https://images.homedepot-static.com/catalog/pdfImages/99/998d8cb0-b7f8-4d16-a73f-39bfc89b8744.pdf
In the case of this gypsum, the ratio of gypsum to water is 100: 35.
![20](img/group/week10-group/20.jpg)
![21](img/group/week10-group/21.jpg)
Sunghyun tried coloring with acrylic paint. It cured well and it has really hard surface.