Steps to Making a Resin Skull (Mold Making and Resin)




Introduction: Steps to Making a Resin Skull (Mold Making and Resin)

Before beginning this process, I want to include that using both liquid rubber and resin creates very pungent fumes that could be toxic and it is highly recommended that you work on this in a well ventilated area or outside!!

In this Instructable, I will be sharing the process of how to cast an object (for me I used a small skull because spooky season, but you can use a small object that you already have) and then using the mold to cast the object in resin!

Before we start, I am a college student and doing this on a budget, I had a few of these items before from previous projects, but I tried my best to find cheaper options and use what I had already available to me.


For Mold Making:

  1. Amazing Mold Rubber (High Strength Liquid Mold Making Rubber)
    1. This comes in two parts, the base and the catalyst
  2. Object to mold (For me a skull)
  3. Container for the mold (Plastic is the best option)
  4. Hot glue gun and glue sticks
  5. Something to stir the liquid rubber
  6. Popsicle Sticks
  7. Rubber gloves and mask
  • Optional Materials:
    1. Separate cup to mix the liquid rubber in

    For Resin Making

    1. Clear Polyester Casting Resin with catalyst (Brand: Castin' Craft')
    2. Mold Release (Brand: Castin' Craft')
    3. Your mold
    4. Rubber gloves and mask
    5. Cups to mix the resin in
    6. Alcohol spray
    7. Things to protect your work space (paper towels, newspaper, plastic drop cloth)

    Optional Materials:

    1. Liquid dye
    2. Pigment powder
    3. Glitter
    4. Embeds
  • Step 1: Getting the Object Ready to Mold

    For this step, you are going to need:

    • Your object
    • Your container of choice (plastic is recommended)
    • Hot glue gun and a glue stick

    Take your object and place a small bead of hot glue to stick your object to the base of your container. This makes it so the object does not move around in the liquid once it is added in. Once the hot glue is hardened, you are ready to move on to the next step.

    Step 2: Mixing and Pouring the Liquid Rubber

    For this next step, you will need:

    • Amazing Mold Rubber
      • This is a two part molding process, one part being the base and the other being the catalyst.
      • You can also use another type of liquid mold maker if that is what is available to you, this is just what I could get my hands on at my local store.
      • Something to mix the two parts together
    • Your object in the container
    • Rubber gloves and mask

    Optional Materials:

    • A separate cup to mix in if you are using a smaller amount of liquid rubber
    1. Begin by making sure you are in a well ventilated area or possibly outside. If you are sensitive to smells, it can be strong and that is also why wearing a mask is recommended.
    2. Read the instructions on the kit to know the exact proportions you will need of base and catalyst.
      • For me, I used the whole container of the base, and for this you will add the entire bottle of the catalyst.
    3. Combine your two parts and mix well, I mixed for about 2 minutes to make sure that the two were well mixed and the color of the liquid was even.
    4. After it is all mixed, you will begin to pour the liquid:
      • Make sure you are wearing gloves for this step!
      • Try to pour from one side of the container to reduce the amount of bubbles created within the mold.
      • Make sure that all parts of the object are covered, you will have some working time to make sure this happens
    5. After your liquid is poured and your object is covered, now we wait!
      • On the box, it says that cure time is 2-4 hours, but I recommend leaving it over night for best results.

    Step 3: Demolding Your Object

    After your mold is done curing, it is time to take your object out of its mold!

    • For this process, I recommend going slow and taking your time.
    • You may need to use something else to help get your mold free from its container, like a popsicle stick.
    • You will need an X-acto Knife to make a small incision to release the object

    Freeing Your Mold and Object:

    1. Begin by removing the rubber mold from the container, use a popsicle stick to help get in-between the rubber and plastic container.
    2. After you have removed it from there, now it is on to the object.
    3. Because we put a small dot of hot glue, there should be a spot already that does not have any rubber on it and is a good starting place to know where to remove the object.
    4. Start by making a small incision and check to see if the object can be moved or taken out, if it can't that make the incision slightly larger and try again.
    5. Once the object begins to move and you are starting to have it come free, work slowly to not ruin the mold or the object.
    6. When you have gotten your object out, celebrate that this part of the process is done and you have yourself a personalized mold!

    Step 4: Prepping Your Mold for Resin

    For this step, you will need:

    • Your mold
    • Mold Release
      • You can use an actual store bought mold release agent for this
      • You can also use common materials like vegetable oil, mineral oil, cooking spray or petroleum jelly which is a much cheaper and more available option
    1. Take your mold and simply spray or apply your mold release before even beginning the resin making process.
      • This will make your life much easier in the end I promise.

    I know this seems like a small step, but it will reduce the chances of your resin object getting stuck, make the demolding process much easier, and help keep your rubber mold intact.

    Step 5: Mixing Your Resin

    **Disclaimer** The smell of resin can be very strong and very irritating to the nose, throat, and lungs. Please make sure you are in a well ventilated area when using resin and make sure you are wearing gloves and a mask to protect yourself as best as possible. If possible, try to do this outside or in a space with many windows open.

    For this step, you will need:

    • Resin of choice
      • I am using Castin' Craft casting resin and the catalyst
      • You can use another kind, just make sure you read the instructions so you know how much of each part to use to make your casting successful
      • Mask and Gloves
      • Something to stir with
      • Cups to mix the resin in (something that you are okay with being thrown away or used specifically for resin)
        • The best thing to use are small measuring cups that have liquid measurements on it so you know how much of each part you are using.

    Optional Materials

    • Pigment powder
    • Liquid pigment or dye
    • Glitter
    • Embeds (dry flowers, sequins, shells, etc.)

    Mixing and Making the Resin:

    1. Start by reading the instructions for your resin!!
    2. If you want to add embeds, pigment, or glitter here are the steps for that:
      1. Add your pigment or glitter into your base before you mix in your catalyst!
      2. This is important so you have enough time to mix in everything without the fear of your resin setting up while you are still adding things in.
        • If you would like to put in large objects like flowers or shells, you can do this before or once the resin is poured into the mold so it does not throw off the proportions of the base and catalyst.
        • Combine the necessary amount of base to catalyst and mix well (I recommend 1-2 minutes to make sure all is well combine)

          When you have finished this step, it is time to pour your resin into its mold!

    Step 6: Pouring Your Resin

    1. For this step, you will need:
    • Your mold
    • Your resin mixture
    • Gloves and mask
    • Something to help pour the resin (Popsicle sticks)
    • Something to cover your workspace incase of spills
      • Paper towels
      • Newspaper
    • Alcohol spray (to pop bubbles)

    Again, please make sure you are in a well ventilated area, resin is strong and can be very irritating!!

    1. Now that your mold is prepped with mold release and ready to go, it's time to pour the resin.
    2. Go slow when pouring the resin mixture to avoid bubbles and to make sure you are not overfilling your mold.
    3. Once your mold is filled, there may be some bubbles that have come to the surface. You can pop these by using a diluted alcohol spray.

    Now that the resin is poured, wait over night or 12-24 hours to see your creation!!

    Step 7: Demolding Your Resin Creation

    This is the final step!!!

    Since we used mold release, this process should be pretty easy!

    • Take your mold and slowly tug on the outside to release the resin from the rubber.
    • Gently work at releasing it like we did when removing our object from the rubber mold before.
      • We don't want to ruin the resin or the mold so take your time

    Once it is out, you have yourself your very own resin creation and personalized mold!!

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