Picture of 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:
  • water
  • blue dish-soap (any brand seems to work)
  • 100% Silicone (do not buy quick set silicone, you need 100% silicone)
  • bowl
  • caulking gun
  • something you want to make a mold of.
  • scissors/knife
  • masking tape - to patch holes in your positive, if necessary.
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Step 1: Make your catalyzing solution.

Picture of 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.

Picture of 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.

Picture of 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)
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BMm12 days ago

I tried to handle it and even putt some small amount on my arm while it is wet, nothing happened. but Ill tr to look for some food grade silicon I think that's much safer :)

BMm116 days ago

im a girl and i just want to ask if is it safe to make something penetrative (if you know what i mean) out of that 100% silicone?

audreyobscura (author)  BMm110 days ago

Hey there - i feel like this is the question i have been waiting for since I published this Instructable. I'm pretty sure that this 100% silicone off-gasses acetic acid as it cures - it would just need to be neutralized before....well. have fun!

thank you for the reply, one more thing. how can I nutralized it?

audreyobscura (author)  BMm13 days ago

audreyobscura (author)  BMm13 days ago

Maybe a baking soda bath? But this isn't medical grade tested - I would pursue further education about materials that may not irritate your skin. Or do some patch testing on your wrist of a neutralized cured silicone, at the very least.

CarolineK210 days ago

Can you used water based clay for making the original for this? If so, will it need a release and should it be wet or dry when making the mold?

IamTheMomo10 days ago

Can it be extruded? I have some small decorative glass bottles that I like to keep vanilla and other extracts I make in, and I can't find corks to fit well. I'd like to extrude a cylinder that would fit in my bottles, then top them with something larger, such as a button or glass marble.

BMm115 days ago

how about putting something hard inside it?

kelli196316 days ago


timevortex17 days ago

how would/could you cast the whole figure at once?

Cannot wait to do this!


i dont think that is a normal occurrence maybe get it checked out. depending on the kind of silicon you used it could have dried to youre hands and that is what you saw

The acetic acid in the silicone is burning your hands as it cures. Wear gloves as I heard that your skin absorbs up to %20 of what it touches.

amvancourt28 days ago
I've always used Oderless Mineral Spirits and/or WD-40 to clean hands of residue. Bonus tip: Do not smoke.

thanks! And that's always a good tip! haha

I need a exact mold of my hand. any suggestions ?

Try alginate! this video might help:

soooo...i made a mold just now, it's currently curing, and the silicone was NOT fun to get off my hands! Just a warning for those who have never used it. Any tips on how to get off the silicone?

Not sure of any easy ways of removing it, maybe try acetone.. Gloves might be a good investment :P

izzyev1 month ago

soapy water is to silicone as flour is to pizza dough.

Where did you buy your l.e.d.s and your resin? How long did the l.e.ds last?

So, if this mold is made from pure silicon, does that mean it's food safe? Can it go in the oven and freezer?
paqrat3 years ago
This is way cool. Have you tried it with the white silicone caulk?
I have. It... didn't end well. The pigment in it felt like it was burning my hands after I started pulling it out of the soapy water. I'd stick to using the clear.
Back when I had aquariums there were some folks making their own aquariums and someone said you didn't want to use some of the bathtube silicone caulk cause they have some sort of fungicide in them to prevent mold in the caulk. That may be what you felt on your hands.

Sounds like they really designed it to prevent mold! (get it? because molds)

Rubber gloves... problem solved!
I've had issues with the silicone sticking to gloves and generally becoming a huge mess. I suppose "huge mess" is better than, "it burns!", but I always preferred the greater dexterity.
Absolutely. These are chemicals. Soap removes the protective layer of oil on your skin, allowing the chemicals to penetrate your skin and cause potential harm, perhaps including nerve damage. I worked every with silicones for ten years, and have been given this info as professional training. Please, protect yourself. I know that sounds like your mother... there has to be a better way!
I think the safety issue is an important point an well made but it is also worth reminding that the silicone mix we are making will stick to silicone. I have used large quantities of this mix and tried to use a large silicone spatula to assist me with the mixing and of course I've still got mixture firmly stuck to it. However the cheap rubber gloves available in uk thrift stores don't stick at all.
Rubber gloves wouldn't stick to the silicone caulk?
It needs to be 100% Silicone caulk, aka "the clear stuff". Most of the other Silicone's actually have latex and other additives mixed in and don't work well at all. Plus, they are more expensive.
That's important enough you should mention it in the 'ible itself!
I had trouble with white silicone but great success with same brand grey silicone!
audreyobscura (author)  paqrat3 years ago
I haven't - if you try it let me know how it goes!
I think I have some white silicone tub caulk. I'll check it out and may try it this Sunday.
paqrat paqrat3 years ago
Turns out what I have is latex. I'll try picking some up though next time I hit the store. I think I'll stick with the clear though.
AudreyObscura(CoolName!): To add to your great guide: A neat trick I found online a few years ago, is to add a few drops of Acrylic(!) hobby paint( about 2-3drops per dixie cup of silicone caulk ) and mix well. The Acrylic paint also acts like a nice colorant and mix indicator, but it's water contents causes the silicone to cure solid throughout the mold like regular 2part molding compounds. I think this is what the soap is also doing.

I've used this to make custom insulators and rubber-Sugru-like items. If you want a courser texture add a little cornstarch. -Lee Studley
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