World's easiest silicone mold.

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!

Comments

[cbernards leiberan-titus]

This is so awesome! Thank you so much for sharing these instructions. :)
Do you think the mold could go in the oven, like silicone baking products? I was thinking this would be awesome for making custom crayon molds.... but I don't want to kill myself with off-gassing or chemicals.... Thank you, this looks like such an awesome idea!

[stayputnik]

Silicone generally is heat safe up to about 500 degrees F (give or take). If the stuff you're using is genuinely 100% silicone, it should be fine in the oven... especially at the temperatures needed to melt crayons. Might want to open a window just to be safe. :-) Let us know how it goes!

[Dark Light]

This is neat! Caulking isn't just for bathtubs anymore. lol. Thanks for posting this...I'm sure I'll get some use out of it.

[paqrat]

This is way cool. Have you tried it with the white silicone caulk?

[cthulhulovesme]

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.

[jaybo2099]

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.

[Broom]

That's important enough you should mention it in the 'ible itself!

[paqrat]

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.

[stringstretcher]

Rubber gloves... problem solved!

[paqrat]

Rubber gloves wouldn't stick to the silicone caulk?

[cthulhulovesme]

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.

[stringstretcher]

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!

[audreyobscura]

I haven't - if you try it let me know how it goes!

[studleylee]

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

[paqrat]

I think I have some white silicone tub caulk. I'll check it out and may try it this Sunday.

[paqrat]

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.

[maggieelrod]

I love this idea but really want to figure out how to make a very large mold ( with both sides, so it can be put together) of a large urn. Does anyone have any ides?

[fjordcarver]

Mix cement or grout with silicone to make aquarium safe, textured models. You have to leach them (soak, dump, soak, dump) to make sure they don't interfere with ph balance if they are going in a water tank. For a terrarium I wouldn't bother, but let them cure well.
It is water that accelerates the curing. water in corn starch or grout. (which is why in recipes for both these agents, you start with a certain amount of water too add and then add accordingly until mixture is right, depending mainly on air humidity and how much is already absorbed)
The soap releases, which is why it works way better than spit for going around a tub(spit works too, but silicone unavoidably sticks to your fingers and makes a mess eventually)

[fjordcarver]

I just found this because you tried my little app (or someone typed your name in), and because in your stats it was third most popular. I am really glad I found this. Double huzzah, because you tried my app, (another editor...triple huzzah). So thank you for both, ('ible and visit)
I can't wait to try this out. So cool. A liitle dish of water and dishsoap is great to smooth the joints when caulking around a shower or tub too.

Silicone is awesome stuff.

[mediabeing]

Gee, I wish you'd shown us a standard casting so we could see if the mold really works [reproduces detail well]. Oh well. Maybe you'll do that next time. Yippeee!

[danzo321]

I know that this technique can give pretty high quality results, but here I see no t-rex teeth etc. You could lightly grease the object, squirt silicone I on it, and let it cure, and if using the clear, cut the mold with a sharp blade to free the pattern object. But you also should build a funnel in to the mold so you can get resin into it.

[Nirgal38]

If you look at the original images (by clicking on the little "i" in the upper left corner of the images), you can see the teeth. They don't show up in the smaller versions of the pictures because they aren't painted a contrasting color.

I've wondered if silicone caulk could be used to make molds and now I know that it can.

Awesome job!

[eschneck]

Thanks for the tip on the "i" Good Guy Nirgal38!

[killbox]

The water is actually the catalyst, the soap pretty much works as mold release.

you can also do this with pure silicone caulking and a teaspoon of corn starch, (it too will quickly catalyze the silicone.

you can then soap cover your object and your hands and make a mold you only have about 5-10 minutes to work the stuff before it becomes too thick and rubbery.

[codongolev]

that's basically just oogoo, which is definitely great for molding. it'll stand up to the heat of molten solder if you feel like molding a metal lego or cow head (both of which I've done).

[prahs]

I didn't see any mention of how the second half of the mold was made or registered.
I looks like it makes a pretty crude cast, although it does have the sparkle going for it.

[UFO_TOFU]

It looks like this instructable is only for a single sided mold, but I imagine you could make a 2-part by leveling one side before pressing in the positive object, then pressing in dowels for registration. Once the first half is set, remove the dowels but keep the positive object; spray mold release over the mold and then repeat the process and press new silicone into the remaining half. Maybe audreyobscura can expand upon this, too!