A simple and very cheap way to make custom shaped moulds for creating simple resin castings with or without an LED embedded into them.
The mould is based on a popular technique on the Internet which uses common household materials to make good silicone rubber moulds. It's basically just standard sealant silicone mixed with cornflour (cornstarch) to make a malleable putty into which your master shape is pressed. If using non plastic masters then apply some oil or Vaseline to the object so that the silicone doesn't stick to it.
When the mould has cured in an hour or so (but leave overnight if possible) then the master can be removed and the flexible mould can then be used to produce replicas from various resins. I like the simplicity of the two part syringe resins which can be bought at dollar store type shops.
To embed an LED I prefer to use the shorter "strawhat" 4.8mm LEDs as it helps to keep the chip as far back from the front of the casting as possible for good light distribution. Bend the leads to the side at right angles to the LED so that it can be placed across the top of the mould with the LED submerged in the resin.

16 thoughts on “Make custom resin led shapes with silicone moulds.”
  1. Avataaar/Circle Created with python_avatars Bo Dan says:

    Potato starch works as well as corn starch.

  2. Avataaar/Circle Created with python_avatars Doov says:

    "$4.50 in American currency"
    Most countries in America don't use dollars

  3. Avataaar/Circle Created with python_avatars JayCee1965 says:

    Great Scot a cooking with Clive special and a fabulous useful dough to make. This has given me great ideas to make items for different projects that need a repetitive but reusable mould. One can add acrylic paint to the resin during mixing to colour the casting too. It would be one way to make home-made streetlamps or floodlights etc, or security wall alarms or cameras with flashing-coloured mini-LEDs in them. Just make the moulds, make the resin add the LED and leave to cure. Once ready pull out the casting, paint it black to block light bleed, prime it with an undercoat and add finishing topcoat. Where one wants the light to show through mask it off before painting, then remove after painting is done. Cool and useful vlog tip for modellers to use and reuse multiple of times.

  4. Avataaar/Circle Created with python_avatars No no says:

    Non-newtonian feels

  5. Avataaar/Circle Created with python_avatars mega says:

    cursed thumbnail

  6. Avataaar/Circle Created with python_avatars Neville says:

    Cornflower mixture also works well when cooked a 400 deg for 20 min and served with honey butter.

  7. Avataaar/Circle Created with python_avatars weasel box says:

    <3 you literally have played with everything …hee hee

  8. Avataaar/Circle Created with python_avatars Plokman040 says:

    Before he passed away Grant of King of Random used to make this all the time, he nicknamed it Protoputty but really it is all the same process except he tended to put food coloring in his to give it colors. Now if I can find a way to use Caulking Silicone in a "Diy Pourable liquid Mold" style where you can put the object you wish to duplicate in a box and then pour a more liquid mix of silicone over it that will cure and not need to buy the two part kits of SVR Silicone mood making stuff (a well known brand is Oomoo by Smooth-on) I'll be happy.

    Hmmm maybe a idea for you to try Clive? I mean it couldn't hurt to have a liquid silicone mold maker that you can make yourself, cured like the two parts but is much easier to get and cost effective at all times (Caulk is very cheep and sold in most super markets) eh but it is just an idea I'll keep looking myself and if I find something I'll be sure to pass the info along.

  9. Avataaar/Circle Created with python_avatars Greg W says:

    Using a magnet to hold the LED leads in place would work quite well. Could be as simple as bending a paperclip around, sticking it into the silicone, have a bit folded over to be a flat surface for the magnet, then the LED legs on the other surface of the magnet. Or fancier might be build a wooden frame and glue the magnet to that, which could allow for doing a whole row of moulds at once

  10. Avataaar/Circle Created with python_avatars Hani Baba says:

    Your hands also made of selicon

  11. Avataaar/Circle Created with python_avatars AMERICANREBEL ! says:

    Interesting! Thank you BC!

  12. Avataaar/Circle Created with python_avatars Neon Beamz says:

    Hi I have question for the silicone can it be made Flat with LED Neon on Flex?

  13. Avataaar/Circle Created with python_avatars Paul Stafford says:

    When I visit my nieces and nephews, (young kids), I have them find some small rocks, then we make this silicone putty and make molds of their small rocks. Then, I mix up some clear epoxy and put in some glow in the dark powders I bought off FleaBay and then pour it into the molds. The next day, the kiddos have custom glow in the dark stones!

  14. Avataaar/Circle Created with python_avatars john catterall says:

    wonder what other powders you could use….thinking like plaster of paris , Talcum Powder , etc ,,,,,l will experiment with this in mind ,,,,,,,,,,,,,,

  15. Avataaar/Circle Created with python_avatars bhagy n says:

    Thanks a lot for the video!! I do you need to use only platinum cure silicone (addition silicone) for resin castings? Or can you use any type of silicone for resin molds please?

  16. Avataaar/Circle Created with python_avatars cdcollura says:

    Awesome idea!

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