How to Make a Simple Silicone Mold Out of Silicone Caulking




Making a silicone mold can be a beneficial skill to learn how to do. You can take molds of objects you hand build or of objects found in the world. Taking a silicone mold will allow you to quickly reproduce an object for production or art. Let your imagination run wild and figure out how you can use this skill

100% Silicone Caulking (I like Dap clearn)
Green Dish Soap

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    10 Discussions


    7 years ago on Introduction

    A little more detail on getting your object out after it sets would be good. I assume you exacto knife a slit and pop your original out?

    2 replies

    Reply 7 years ago on Introduction

    That will be my next video, thank you. Yes, use an exacto knife and carefully choose where you will make the incision and how big it will be. It needs to be big enough to get the original mold out as well as the material you are going to choose to fill the mold with. Sometimes it is a delicate material that can break easily when trying to take it out of the mold, so size of the slit and where it is placed is important.

    Ingenious use of silicone caulking.

    Will you be adding a Mother Mold (plaster) to support the silicone?

    How long does it need to cure? Does the soap hinder the curing of the silicone?

    3 replies

    When making a mold I choose to take either a plaster or silicon mold, but have never used them both together. I can see where it could be beneficial to make a second plaster mold to hold the silicone in place when filling. For example the shape I covered in the video became very floppy when the object was taken out. It could have used support when filling it, but then the question becomes, why not just make a plaster mold. Do you make a second supporting mold?

    I choose what material I will use based on the object. If the object has a lot of undercuts, small grooves, and crevasse then silicone is the way to go because plaster will harden and crack when you pull it apart.

    Depending on how thick you make the silicon will dictate how long it will take to dry. I generally let a mold dry for about 30-60 minutes or longer if the silicon is more than an 1/2 thick. I am not sure if the soap affects the drying process. I make the assumption that when agitating the silicone in water the chemical that keeps it soft in the tube is released, thus making the drying process faster.

    Happy Mold Making :)

    The silicone gives you the fine detail and pulls away easily when demolding. The plaster mother mold gives it the support it needs while the casting material sets. When making castings of dinosaur bones they use silicone and fiberglass. I haven't done it but seen it many times in books, on TV and online.

    30-60 minutes? I let my small 2-part molds cure several days and still had some gooey spots. About the size of two 9-volt batteries. (1 inch figures circa 1986) Another Instructable says that the glycerine in the soap speeds up the curing.

    AranoGreenish Apple

    Reply 7 years ago on Introduction

    Maybe ogoo is an alternative.


    7 years ago on Introduction

    Please say silicone, not silicon. We have ppl here who could work with silicon! If you get the mold surface wet with soapy water, an x-acto blade is much easier to use.
    As a pro moldmaker I assure you, sometimes you need not only a mother mold to stabilize your mold, but an intermold between them so the mothermold is not too complex and the primary mold is not too thick.