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10. Molding and casting#

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

Material Datasheets#

Smooth Cast 300#

  • TB / SDS
  • Color: White
  • Pot Life: 3 minutes
  • Cure Time: 10 minutes
  • Mix Ratio By Volume: 1A:1B
  • Mix Ratio By Weight: 100A:90B

  • liquid plastics. ultra-low viscosity casting resins
  • Not a hazardous substance or mixture
  • safety glasses and gloves recommended
  • some heat of reactions

Mold Star 16 Fast#

  • TB / SDS
  • Color: Blue-Green
  • Pot Life: 6 minutes
  • Cure Time: 30 minutes
  • Mix Ratio By Volume: 1A:1B
  • Mix Ratio By Weight: 1A:1B

  • platinum silicones
  • Not a hazardous substance or mixture
  • safety glasses and gloves recommended

Smooth Cast 325#

  • TB / SDS
  • Color: Clear Amber
  • Pot Life: 2.5 minutes
  • Cure Time: 10 minutes
  • Mix Ratio By Volume: 1A:1B
  • Mix Ratio By Weight: 115A:100B

Safety datasheet part A

  • Polyeurethane Elastomer…flexible
  • Safety Requirement: wear eye, mouth/nose, gloves, sleeve protection
  • Don’t eat or breathe, touchng will cause irritation
  • Part B…no hazzard

This material, among the 5 we tested in the lab, is the one with the greatest hazzards. Many of them Class 1 and 2 (the highest risk) Eye, nose, mouth, skin protection needed to work with this material.

Ecoflex 50#

  • TB/SDS
  • Color: Translucent
  • Pot Life: 18 minutes
  • Cure Time: 3 hours
  • Mix Ratio By Volume: 1A:1B
  • Mix Ratio By Weight: 1A:1B

  • Platinum Cure Silicone Rubber Compound
  • non-hazzardous
  • safety glasses and gloves recommended

Sorta Clear 37#

  • TB / SDS / Food Safe Technical Bulletin
  • Color: Water Clear Translucent
  • Pot Life: 25 minutes
  • Cure Time: 4 hours
  • Mix Ratio By Volume: 1A:1B
  • Mix Ratio By Weight: 1A:1B

  • Food safe
  • Non-hazzordous
  • safety glasses and gloves recommended

Safety Prepartations#

Taking safety seriously.

  • Goggles
  • Masks
  • Apron with sleeves (avoid particles attaching to our clothing)
  • Gloves

Material Observations#

These are our impressions of working with the various materials. All the materials were 2-part mixes of two chemical compounds in liquid form.

Mold Star 16#

  • Use: As the name suggests, the primary use of this material is for making casting molds
  • Pour: Medium viscosity…pours like thick honey
  • Mixing: Mixes with a bit of effort…the 2 parts are different color…must mix until it becomes a single color
  • Curing: Fast cure time…non-malleable after only about 5mins
  • Post Processing: Can post-process away flashing and burrs with a sharp knife…no other post-processing needed
  • Finish: Cures into a flexible but seemingly strong, solid blue color finish. Peels easily away from wax molds.
  • Flexibitlity: Second most flexible among the materials we tested, bends and distorts with little force

Smooth Cast 300#

  • Use: Used primarily for final object Casting
  • Pour: VERY low viscosity…pours like thin honey

Pro tip: use chopsticks under the lip of the container when pouring) to control the direction of the pour stream…prevent dribbling back to the side of the canister

  • Mixing: VERY easy to mix…but be mindful of making bubbles
  • Curing: Cures in minutes…starts to harden within a couple of minutes, full hardness at 10 minutes; tangible warmth when curing
  • Post Processing: Can post-process away flashing and burrs with a sharp knife…not certain if it can be sanded
  • Finish: Hardens as a beautiful, opaque white plastic finish
  • Flexibitlity: Zero flexibiltiy

Smooth Cast 325#

  • Use: Not certain why this material would be used when other better, low-hazzard options exists…
  • Pour: Medium viscosity…pours like thick honey
  • Mixing: Mixes with a bit of effort…but be mindful of making bubbles (it is possible that we either did not get the mix ratio between part A and B correct or did not mix well…which led to poor results)
  • Curing: Long cure time…hours; tangible warmth when curing
  • Post Processing: Can post-process away flashing and burrs with a sharp knife…not certain if it can be sanded
  • Finish: Hardens as a semi-opaque white plastic finish…not so beautiful
  • Flexibitlity: Zero flexibiltiy

Ecoflex 50#

  • Use: Used for making soft molds (?)
  • Pour: Medium-high viscosity…pours like thick honey in cold weather
  • Mixing: Mixes with a bit of effort…tendency to generate big bubbles that stay trapped in the material if mixing is too rough
  • Curing: Long cure time…hours
  • Post Processing: Can post-process away flashing and burrs with a sharp knife
  • Finish: Cures as a semi-translucent finish of reasonable eveness
  • Flexibitlity: Most flexible among the materials we tested, bends and distorts easily with little force…may be easily broken if too much force applied (?)

Sorta Clear 37#

  • Use: Not certain why this material would be used when other better, low-hazzard options exists…
  • Pour: Very high viscosity…pours like thick honey on a cold day
  • Mixing: Mixes with a lot of effort, feels like mixing chopsticks would break…big bubbles generated and hard to remove
  • Curing: Long cure time…hours
  • Post Processing: Can post-process away flashing and burrs with a sharp knife
  • Finish: Hardens as a semi-translucent finish…lots of air bubbles trapped (maybe needed to mix in higher temperature??)
  • Flexibitlity: Some flexibility, distorts when a reasonable amount of force applied

Hardness/Flexibility Ranking#