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Molding & Casting

The assignment this week was to review the safety data sheets for each of your molding and casting materials, then make and compare test casts with each of them. However, we had a limited variety molding and casting material in the lab. So what we did is that we used different material to make the mold and then we poured resin testing the different colors we can achieve.

Testing Various Molding Material

In order to perform this week's assignment, we tried two differnt Molding Material and we compared the technical specification and the results. The following material were available in the lab and were used during this week's assignment:

  1. Alumilite - Amazing Mold Rubber
  2. Alumilite - High Strength 2

Concerning safety usage, both material had the same safety descriptions:

Always use safety products when working with silicone and resin. Always wear gloves, apron, coveralls, boots, chemical goggles. Mixed High Strength rubber will absorb into porous materials and may stain! Avoid clothing, carpet, upholstery, and any other porous materials which will stain and will not come out. Mold making and casting is best done in a designated area such as a basement, garage, or hobby room with adequate air movement or ventilation. Cover any surfaces including floors with plastic sheeting, or plywood to prevent damage from spilled resin. To clean up unmixed or still liquid material, use rubbing alcohol on a rag or paper towel to quickly clean and remove. In some instances, such as spills on non-porous surfaces, it's easier to clean up silicone after it's allowed to cure. Then simply peel away and discard.

The following are the safety warning for both material:

  1. Keep out of reach of children
  2. Avoid eye and skin contact
  3. In case of skin contact, wash with soap and water
  4. Use with ventilation. In case of ill effects, remove to fresh air
  5. Keep container closed
  6. Do not take internally
  7. Do not use for food

A detailed discription of the technical data sheet for both materials is described below. You can download the data sheet for the material from the following links:

  1. Amazing Mold Rubber
  2. High Strength 2

Amazing Mold Rubber

The following is a summary of the data sheet of the Amazing Mold Rubber:

  1. Color: Pink
  2. Mix Ratio: 10:1 by WEIGHT
  3. Open Time: 20-30 mins
  4. Demold Time: 2-4 hours
  5. Mixed Viscosity (cps.): 15,000
  6. Specific Gravity: 1.15
  7. Shore A Hardness: 25
  8. Linear Shrink (%): 0.3
  9. Tensile Strength (psi): 550
  10. Elongation: 500%
  11. Temperature Range (F): -67 to 395
  12. Vacuum Required: No

High Strength 2

The following is a summary of the data sheet of the High Strength 2:

  1. Color: Pink
  2. Mix Ratio: 10:1 by WEIGHT
  3. Open Time: 45 mins
  4. Demold Time: 12-18 hours
  5. Mixed Viscosity (cps.): 18,000
  6. Specific Gravity: 1.15
  7. Shore A Hardness: 25
  8. Linear Shrink (%): 0.3
  9. Tensile Strength (psi): 550
  10. Elongation: 500%
  11. Temperature Range (F): -67 to 395
  12. Vacuum Required: No

We can notice that this material takes more time to cure than material 1. However both have almost the same final result which is a high tear strength rubber material.

Discovering Casting Materials

The following material was available in the lab and were used during this week's assignment:

  1. Resin Material - Alumilite Casting Resin - White
  2. Alumilite Coloring Dyes, Various Colors

The technical specification for the Alumilite White Casting Resin is the following:

  1. Color: White
  2. Mix Ratio: 1:1 by Volume
  3. Pot Life: 2.5 - 3 minutes(100g mass @ 75 degrees F)
  4. Demold Time: 5-15 minutes(100g mass @ 75 degrees F)
  5. Mixed Viscosity (cps.): 90
  6. Specific Gravity: 1.05
  7. Shore Hardness (ASTM D-2240): 72 D
  8. Shrinkage (in./in.): 0.006
  9. Tensile Strength (ASTM D-638) (psi): 4,500
  10. Elongation: 10%
  11. Temperature Resistance: 185 F

You can download the data sheet for the material from the following link: Amazing Casting Resin

Testing Casting Material

We had only one type of resin material that we used in this week's assignment. However, we had a variety of coloring dyes. So what we did is test pouring resin using various colors. Some parts were poured all in one color. Other parts were poured in phases, thus having a combination of different colors in the same end product.