DIY Silicone Molds - Excerpt

This is an excerpt from a longer lesson on glass casting. In this brief tutorial, we cover the creation of reusable silicone molds using silicone caulking, dish soap, and corn starch.

WORKSHOPS & COURSES

SOCIAL MEDIA & CONTACT

[ember]

Silicone pulls moisture out of the air and moisture is what is needed for it to cure. Cornstarch also pulls out moisture from the air. By mixing the cornstarch in the silicone pulls in more moisture faster. The more cornstarch you use the faster the silicone cures. I have done the cornstarch method and used much more than here creating almost a clay consistency. This worked well for what I needed but it set completely in less than 10 minutes at about 1/8th inch thick so you have to work fast. I also made molds that was about 3/4 thick and was able to remove my piece from it in about 30-45 minutes. For those who want to know how I mixed it, I put a large pile of corn starch in a pan (1/2 the box) added the silicone on top and started working it like bread dough. When it gets enough cornstarch in it that it no longer sticks to clean dry hands is when I started to shape it.

[sailingluanacordelia]

👍. Silicone is hydroscopic so it requires water to cure, not air. Humidity it cures faster and the longer it's exposed to water the harder it gets till it starts to break down. This is why boats do not use silicone for repairs.

[Theperilsofbev]

BEST molds tutorial I've seen as if yet! Thanks so much

[ladisavage]

This video was extremely helpful and detailed!!! The best one ive seen yet and I now feel confident in trying out my method using this stuff!

[chriswampler]

I tried using xylene as thinner for pure silicone and made a bucket full of it. I was able to pour it like water. Have to do it in a well ventilated area or outdoors though.
I have also used the thinned silicone as waterproofing and applied it with a roller.

[xpump]

I use Mineral Spirits or Naphtha to thin down Silicon and cornstarch to accelerate setting.
You can thin it down to a pourable liquid.
I mix in the cornstarch into the thinners 1st to then evenly mix into the silicon to avoid clumping.
Someone posted using Xylene as a thinner, I would avoid that stuff as it extremely nasty and unnecessary.

[soal]

Love this stuff. I've made molds with both methods. The corn starch one grew a pink
Mold on it right away. I do refrigerate it. I have best luck with the dish soap one.
The only problem I've ever had was. .if I just take pieces off a lump an put it back in the soapy water..it get hard very quickly. I usually just use a huge glop of the soapy solution silicone and squish it around and I'm goo to go!..I get good details. I want to make a mold of something that stands on a base but just not sure how to go about it. This video helps.
Thank you ♡

[ashleymartinez]

I tried this a couple different ways, they were similar to yours but not as good. The first mold I put way to much corn starch and my mold dried heavy and hard. I made a Froot Loop mold, it worked but it was so hard, some of the wax Froot Loops came out good but it was to hard to get most of them out. Your way seems much better.. so I’m gonna give it a try! Thank you!

[deannwilson]

Great tutorial. Love the flap idea. Great information. Thank you

[gretavijayan]

Well demonstrated and very clear understanding step by step procedure. Thank you very much. Wud like to watch more of your video

[questioneverything]

Best tutorial on both methods! I’ve seen some people that do videos on this and told people to use the wrong caulk, next thing you know they disable comments! 🤦🏻‍♀️

[wascallywabbit]

Thank you for sharing this video as well as your knowledge. I'm brand new to the idea of wanting to create a mold of something and have watched multiple videos on the topic and this was the best one that I've come across thus far.

I am brand new to a painting art craft as well (I was hit by someone texting and driving, leaving me permanently disabled. Trying to find an outlet to focus on to distract me from the pain as well as fill in all the empty time and isolation) I have a 2 piece trinket box that I'd like to replicate. I think using these method, I'll be able to apply this to create a single (solid version) of the figurine, as well as taking apart the original trinket box (remove the top screwed on with a hinge) I should be able to unscrew the top, then cast a mold of the 2 separate pieces to allow me to make a trinket box where the top will just rest on the other portion (and/or will perhaps leave me the ability to adhere a small hinge)....anyway, point being.... I think I can do this, using your technique to make a mold so I can cast it using plaster so I can paint it using my new found painting technique or maybe even cast it using resin.

Fingers crossed 😊

[nonitas]

Best video I’ve watched so far! Extremely helpful and informative. I’m extremely grateful. Thank you! ❤❤❤

[dn]

I used 2 full containers like he has here and poured it into a plastic water bottle then plunged my Vaseline coated statue into the silicone and I squeezed the plastic all around, in hopes that I covered my statue fully… now, i let that sit outside over night, and then wrapped it in a heating pad on medium… I wish I had seen your video and tried your method. I am going to leave my experiment be for probably a week to make sure it is fully dried and cured before I try taking my statue out. My method is a total amateur experiment. I wanted to make a mold of this little detailed, vintage statue i have.

[stevestokes]

This I one of the best tutorials on mold making

[paulinehunt]

You are first person I have seen do layering. Seems to make more sense for drying.

[moonolyth]

A note: Silicon uses moisture to set so you can mix in a little acrylic paint and mix, (if you can) and this will allow you to make a thick mold and cure completely through.

[katylowe]

Found this in my search for a way to copy a wood base molding profile. Dogs chewed moldings years ago and now it is time to repair them. Thinking if I make a mold for the wood filler it will give a better result than free hand sculpting to match adjoining molding. I’m going to use your cornstarch recipe. Thanks.

[lezbriddon]

clear silicon is the strongest, the white/black/brown are weaker as the pigment doesnt add strength but reduces the amount of real silicon in the mix.

[kensullivan]

Cool beanz I am gonna use this method often from now on. Thank you.