World's Easiest Silicone Mold.




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Intro: World's Easiest Silicone Mold.

Yep. That's right. I am about to change your mold-making technique forever. This simple way of silicone mold-making will have you wanting to make casts of all your trinkets and toys.

You will need:

2018 Edit:

If you are looking to use this mold making technique to do life-casting or food casting, these molds are not skin or food safe.

I recommend these kits:

Step 1: Make Your Catalyzing Solution.

By mixing a high-concentration of dish soap with water in a bowl, one is actually making a catalytic bath for your silicone. The glycerine in the dish soap accelerates the cure process for of your 100% pure silicone.

This is by no means an exact science, I use blue dish soap because it allows me to see how much I have added to a water bath, I approximate that I used 4 oz. of soap in 64 oz. of water.

Step 2: Catalyzing the Silicone.

Cut off the tip of the silicone caulk tube, and set it in the caulking gun. Unload enough silicone to surround the desired object, into the bath.

I use the whole tube usually.

Step 3: Preparing the Silicone.

While keeping your hand submerged in the dish-soap catalyzing bath, gently clump the string of silicone together. Form it into a ball, and slowly massage it. Fold it, stretch it out, and work it very much like one would knead dough.

When it begins to become a bit less malleable, and stiffen, it is time to sink your positive into your material. In this case, Mike helped me, and we used his dinosaur, Jesus. (hay-zoos)

Step 4: Make Sure the Mold Is Water Tight.

The best way to make sure your mold is watertight is to add a kind of thick-ish layer of silicone to the surface area of your object. Note how the dinosaur is padded by about a 1/2" layer of silicone all around its body. Also, I have left a considerable amount of the dinosaur uncovered, as I am only casting half of this figure.

You want to make sure you can still wiggle your figure out of your mold, without any of it getting caught, otherwise it can be very tricky to extract once your mold has set.

Step 5: Let It Cure.

It will take about an hour for a full cure of your mold, before you can use it. Allow your object to remain in the mold while it cures. When the mold is no longer tacky to the touch, and feels rigid, gently remove your positive.

We kept this mold on top of the fridge, and put a bit of soapy water down on the plate so that the silicone didn't meld with the paper plate.

Also, this part smells awful. Make sure you do all this in a well-ventilated space.

Step 6: Use Your Mold!

We made a sparkly rendition of Jesus with clear casting resin and glitter. When the resin began to gel we set three LEDs inside of him. Behold the sparkliest light up dinosaur in West!


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418 Discussions


Answer 4 days ago

It is DAWN, and get only the blue color liquid. It has properties that no other dish soap has. I don't know what's in it, but it is called for specifically in a few crafts I do. I don't recommend actually using it to wash your dishes unless you wear gloves. It does a great job of cutting grease, but will strip the natural oils from your skin too and cause them to crack and bleed if you immerse your bare hands in it on a regular basis. I'm not the only person who has had that happen. I've actually met a random person with cracked bleeding hands and asked them if they used blue Dawn to wash dishes, and they said, "Yes!" The product has been used for decades to clean up animals in oil spill distasters, so it does have great uses. The manufacturer claims it is "gentle and safe".


4 weeks ago

I was a theatrical costumer and prop builder for about 40 years. I have worked with silicone of all types for years. I followed directions to the t. I kneaded the silicone for over 30 minutes and it gained only a mild firmness. Cured for 4 days, still sticky. Just how long do you have to knead this stuff? I also tried the silicone and cornstarch. It worked beautifully.

2 replies

Reply 4 weeks ago

Huh, I've never had that happen! I wonder if it has to the with the temperature, or if not enough water was worked into the goopy mixture. I am yet to try the silicone and corn startch technique, but I just ordered stuff to try it!


Reply 4 weeks ago

After speaking with others who had the same trouble I figured it out. Your instructions say "While keeping your hand submerged in the dish-soap catalyzing bath, gently clump the string of silicone together. Form it into a ball, and slowly massage it. Fold it, stretch it out, and work it very much like one would knead dough."

I tried adding "Remove from water" before proceeding to the second sentence and finally got that horrible smell and it set. I work in a field where instructions must be followed exactly as written or research results are flawed. I'm sure I'm not the only one who had to make it twice to figure it out!

Dollar stores usually carry cornstarch you might try to get it there. I'm not sure which recipe you are using, the one I use is nothing but silicone and cornstarch. Here are some hints: I start by putting the cornstarch in the bowl first and spread it out. This keeps the bowl and process less sticky all the way around. If your recipe says to wrap in plastic, seal in a container and let sit, be careful. Depending on how much cornstarch you add that step is not always needed. I use this rule of thumb: if it is mixed and feels firm/unsticky enough you can use it right away. This method does not make the silicone smell bad either!


Question 5 weeks ago on Introduction

I enjoyed your instructions on mold making. Have you tried making a two or three part mold? If you did, what did you used to keep the silicone from sticking to the first part?

Thank you.

Claude Thibault

2 more answers

Answer 5 weeks ago

I've found that this mold is pretty difficult to tear, you should be able to stretch it a little bit to free your part.


5 weeks ago on Step 6

Learned something new !

No mix silicon in blue Dawn and water.. Wow so Easy......

Thanks :-))


Question 7 weeks ago on Step 4

Can this method be used to make a silicone mold of my arm or hands? Will it stick to my skin?

1 more answer

Answer 7 weeks ago

Hey there - I actually just added this edit to the top of the Instructable :D This is not a safe method to use to make molds of your skin, but you still have plenty of options!

To make a reusable mold from somebody's body I highly recommend the SmoothOn Body Double Silk product, if you care less about repurposing the mold, or are just making a one-off, consider using alginate.


Question 5 months ago on Step 1

Can you use this process to make a full mold, not just half of the figure? I need to make an ice sculpture for a challenge. I wonder if I can use this process to make a mold of a plastic action figure that i could then possibly cut in half to remove the plastic figure (positive) and be left with the negative mold in 2 parts. Then if i can figure a way to glue it together with a hole to pour water into- i could then position to make the needed ice sculpture. Then once frozen, i could cut away the mold to reveal my figure - What are your thoughts on this?

2 more answers

Answer 3 months ago

There are multiple videos on youtube showing how to do this. Search for "DIY 2 part silicone mold". Also check out the Smooth-On company website for many useful casting and molding technique videos.


Answer 7 weeks ago

Heya, you can cast anything but food into this mold, it is not safe for food consumption


2 years ago

I'm trying to add a silicone 'lip' to an existing dustpan, to make it pick up the little dust bits better. Do you think the silicone would attach? Should I score up the edge of the dustpan to make it adhere better? Should I put the silicone straight on, shape it, and let it cure, or use another method? (If there's a better place to be asking this in, please let me know!)

1 reply

Reply 2 years ago

Silicone sticks to almost anything, but polyethylene is almost impossible to glue to. Maybe start with a dustpan made of something other than polyethylene.