World's Easiest Silicone Mold.

2,777,703

2,325

441

About: I'm a Community Manager at Instructables and the voice of the robot on Twitter! www.twitter.com/instructables Tell me what projects you want to see in our Twitter feed! When I'm...

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!

____

This project uses affiliate links that help me make more awesome DIY projects and tutorials - thanks for your support!

13 People Made This Project!

Recommendations

  • Pets Challenge

    Pets Challenge
  • Sensors Contest

    Sensors Contest
  • 1 Hour Challenge

    1 Hour Challenge

441 Discussions

1
None
Mimi Westcott

Question 6 weeks ago

I have a fairly large wooden statue that is shiny. I know it would take a lot of product to do this but my question is, would it damage the finish on the statue? It is my mothers statue and I would like to surprise her and make a resin copy for the garden. I do not want to damage it.

0
None
ImmortalCryptic

Question 6 weeks ago

Did you use anything as a mold release for it, when you did the glitter resin?

0
None
LynnG64

8 months ago

Can this technique be used to make a silicone handle for a kitchen pot?

2 replies
0
None
bucklipeLynnG64

Reply 7 weeks ago

Yes.
The cornstarch/silicone makes a stiff dough consistency.
Make a batch and mash it around the handle I would make it at least 1/4" to 1/2" thick.

0
None
audreyobscuraLynnG64

Reply 8 months ago

I think for that, you would actually need to cast into a plastic mold, silicone can't be cast into a silicone mold.

If you know someone with a 3D printer, you can make a two-part mold with one of those, then buy the right kind of silicone that would pour and make that shape.

0
None
bucklipe

7 weeks ago on Introduction

In every description of making silicone molds using Dawn and 100% silicone mention to be sure to get the tube that warns of acetic acid/vinegar smell. In your ingredient list I think you need to include that.

1
None
TaraK33

Question 4 months ago

Thank your for this! My molds turned out great, set well, etc. But....

When I then use the silicone molds to MD resin, the side of the resin that is in contact with the silicone remains sticky, as if it isn't fully setting. The sides that are left exposed to air are fine. The same resin has set fine in other molds, and this has happened across multiple resin batches/mixes, so I dont think it's an issue with the resin alone. How can I get a full resin cure in these diy silicone molds?

They unmold fine just the unmolded surface is sticky.

My molds still smell of acetic acid (vinegar), is that part of the issue?

1 answer
0
None
audreyobscuraTaraK33

Reply 4 months ago

Hmm! That's interesting! I'm not sure I have a solution to this issue. I've been thinking about re-shooting this Instructable because it's been so long and I've learned so much from everyone's comments in this Instructable! Check out all the comments and see what you can find that may be useful!

0
None
Wicked Quilting

Question 4 months ago on Step 4

Hi, I have two questions. 1. If I make a mold can I put the same object back in the mold? (I want to make a mold to resin over a large object to contain and smooth the resin after I add additional items to it. The item is moon shaped) 2. Did you coat the inside of the mold to help remove the resin after it dried?

1 answer
0
None
audreyobscuraWicked Quilting

Reply 4 months ago

Hey there!

You can coat the inside of your mold with mold release to help get it out. (https://amzn.to/2UuKTiT)

I'm not sure I entirely understand what you mean by putting the object back in the mold to cast around it, but to smooth the surface of rough wood or plastic, I've used this spray on resin(https://amzn.to/2CX6ERk) with varying degrees of success. My tip is to hang the object somehow and coat it while it spins, handling it minimally, and read the instructions on the can carefully.

Let me know if you need more help!

0
None
ViktoriaP

Question 1 year ago

I tried this on a ceramic dish but the silicone got completely stuck to it. How can I remove the silicone? Thanks

3 answers
0
None

A single edge razor blade, working against the surface of the ceramic and cutting a bit at a time, then lifting, should free the silicone piece. Patience! and good luck :-)

0
None
audreyobscuraViktoriaP

Answer 1 year ago

Was this an unglazed ceramic surface? The silicone likely penetrated the pores of unglazed pottery. I'm unsure of a way to remove cured silicone outside of brute force :-/

0
None
Mikki G.W

3 years ago

I tried several times to make a mold from a ceramics figurine (unglazed) I made for the project. But the silicone always sticks way too good to the figurine, thus not leaving a very smooth mold. Also very hard to get out.
I never tried to cure it in soap water first, but do you really think that would make the trick? I tried to cover the figurine in oil first, but made no difference.

Now I just have a figurine with a lot of silicone residue all over it, and I can't figure out a way to clean it off efficiently so I can start over

4 replies
0
None
Trent_360_2Mikki G.W

Reply 5 months ago

Lacquer thinner for cleaning. And try putting your item in a condom before covering, leaving the opening open. Let set then pull both condom and item out.

0
None
BrandonG22Mikki G.W

Reply 3 years ago

Ceramic is a pretty porous material, even when glazed sometimes, and the silicone loves to stick to it for that reason. In my experience, using the soap water bath will not change the unfortunate results very much if at all. I don't know a good method of cleaning a silicone stuck figure besides burning the silicone off and I wouldn't advise using ceramic objects for this process, ceramic just doesn't want to play nice with silicone.

If you are still bent on casting it, you could maybe coat the ceramic figure with some sort of resin after it is cleaned to give it a less porous surface...? Something to look into perhaps!

0
None
Mikki G.WBrandonG22

Reply 3 years ago

I'm not too keen on getting it glazed, because I want to keep as many details on it as possible

0
None
KarenW142Mikki G.W

Reply 2 years ago

Hi Mikki! I am an instructor for porcelain and ceramics (35 years) and I tell you that so you know I am not blowing smoke but know the mediums enough to give you help. You can glaze any bisque piece with 2 smooth coats of clear glaze and not lose the detail of your piece. Over coverage is where most folks lose some of the details but you will never be able to get a nice mold from a piece that is not smooth to start with. The mold only replicates what you have, and exactly as it is. You're mold will be so nice once you prepare your ceramic item correctly, and your pieces you pour will too! Good luck!