Mold-making / casting

• Wikipedia articles:
  • Molding (process) and Category:Molding processes
  • Casting and Category:Casting (manufacturing)
  • Moldmaker
• how-to information
  • making.unsw.edu.au/learn/casting_moulding_basics/
  • aldax.com.au/mould_making_tech_tips.htm
  • https://www.makeyourownmolds.com/how-to/
  • YouTube playlists:
    • "Molding & Casting 101", by Punished Props Academy (15 videos, channel has 59,000,000 views) [off-site page]
    • "Basics of Mold Making How To Videos", by Smooth-On (57 videos, channel has 40,000,000 views) [off-site page]
    • "Basics of Mold Making", by Alumilite Mold Making & Casting Materials (37 videos, channel has 10,000,000 views) [off-site page]
    • "Basics of Moldmaking and Casting Videos", by Reynolds Advanced Materials (34 videos, channel has 2,400,000 views) [off-site page]
    • "Moldmaking 101: Beginner Tutorials (RAW)", by Iconic Props (9 videos, channel has 30,000 views)
    • "Molding 101", by Dor Friedman (27 videos, channel has 300 views)
    • "Casting, molds, duplicates", by GroundPound MagX (21 videos) — specializes in cheaper / makeshift alternatives
    • (more)
  • instructables.com/Introduction-to-Mold-Making-Casting/
  • sea.museum/2017/03/29/casting-the-past-how-to-make-cheap-easy-moulds-and-casts
  • davidneat.wordpress.com/methods/mouldmaking-and-casting/beginners-basics-mouldmaking-and-casting-explained/
• RTV (room temperature vulcanizing) mold rubber
  • very commonly used
  • can be expensive
  • there's a variety of formulations, not all of them based on silicone
• If you want a high-quality finish, then small air bubbles are a big concern. There are several solutions including compressed air and vacuum degassing, but it seems like most professionals settle on pressure pots as the best overall solution.
  • The downsides of vacuum degassing include — longer production times because you have to wait for silicone to degas before you can use it, it's incompatible with silicone materials that have a short work time, and when degassing, you have to use a cup that's at least twice the volume of the silicone, and still there's always a risk of overflowing and making a mess.
• molds are used a LOT in industrial settings too, of course, and it's possible some of their literature can be relevant to smaller-scale mold-making
  • how to deal with undercuts