Tweet this Video
Share on Facebook
Share via E-mailHow to make a silicone mold in your kitchen on the cheap! Also how to become a play-dough hero for your kid…
The mixture ratio is: 50% Silicone, 50% cornstarch, and mineral spirits to thin. Thats it! The mixture will set up in 5-15 min and cure in 24hours
So does the cornstarch just add volume to the mold or does it have another purpose?
It is not for volume corn starch absorbs water and water makes the silicone set up. So the corn starch makes the silicone set up in 5-10 minutes vs 8hours. The more corn starch the faster it sets up….
Oooh.. okay. That makes sense.
I’ve actually never tried this method of mold making before. I know that people do it but I wasn’t sure about how you went about making the caulk flow properly to get a decent mold with it. I didn’t realize that it could be thinned like that (and I definitely didn’t know about adding cornstarch).
A very useful video!
Great tutorial!
Is it possible to cast metal with that mold?
Tin in particular.
I am not sure about that. I was debating trying some pewter (which has a similar melting point) but never got around to it. Silicone should handle around 300F but given all the additives I am not 100% sure how much heat it can take. So without beating around the bush too much I would say try it out VERY CAUTIOUSLY! Do it outside, well ventilated, wear safety glasses etc etc…..
Great video and I sure could use some hero points at the playdough table. Very Cool.
I wonder is it possible to cast plastic in the mold. Other than that great tutorial.
Yes absolutely! Just make sure that the plastic when it sets does no heat up too much. I am thinking the mold can take 300 degrees or so but not much more
Nice job – you’re lucky though, my daughter woulda busted me for using the wrong color playdoh.
I thought I’d ask/mention – I have made similar molds for plaster and instead of petroleum jelly I used vegatable oil cooking spray (Pam) . Any thoughts?
Spray is fine. basically if it does not stick then you are doing good. I would have used it but I was out of the stuff.
Excellent video…..
I discovered your show with my Roku box and have been a fan ever since!
I saw a writeup about this technique and ran out and bought a tube of silicone caulking to try with with Plaster of Paris. Not done it yet so this was great timing too. Thanks!
Dude! sweet vid. been lookin for ways to make silicone. so sick of buying the kits in the store, 10 bucks for 6 oz. of silicone.. usless.
thankks man!
Glad you like it! I haven’t tried yet but I have been told that if you use glycerine from the drugstore for a thinner it won’t shrink and less stink too! But I haven’t tried it myself so if you try it keep that in mind…
How well does this mold do with making plastic forms from the molds? Like making custom toy parts, like plastic heads or props?
Forget I said anything, found a similar comment to mine.
Great video, really helpful.
I have a bisque-fired ceramic face and would like to mold this. Would this harm the face in any way?
No this should be fine on the ceramic. However get a small piece and do a test first. The solvent may leach into the ceramic and I would not want you to have something wreck.
So i just wanted to throw in a little here. i wanted to make a cheap silicone rubber mold of a rock wall to use in vertical decorative concrete and stumbled across the oogoo, then onto your site. i accidentally ran into a great mixture. see mixed a batch of 50/50 silicone to cornstarch, and it was still kinda sticky as i hadn’t let it sit long. so i sprayed my hands with cooking spray and was needing the mixture by hand. low an behold, the added oil made it very clay like and was extremely mold-able, but not pourable. worked great for making an impression mold. so then i took it a step further. i used a one gallon zip lock back, poured enough mineral oil to coat the inside of the bag, then proceeded to mix in a full 10 oz tube with about 5 or 6 oz of corn starch, and a couple more cap fulls of mineral oil, and last but not least the acrylic water paint. the mixture was awesome, the bag made it super easy to mix and you could tell it was ready for handling when it stopped sticking to the bag. now instead of paying well over 150 bucks for a similar mold that is only 12″ x 24″, i made a custom set from a panel of 24″x24″ for about 50 bucks. figured i would share the mineral oil idea for others to use. PS. it takes about 20 minutes to cure, and i usually peal it off after about 30 to 40 minutes. so far so good.
This is great stuff! Thanks for sharing. Now I’m gonna have to play around a bit. Does the mineral oil leach out of the mold any?
IT does a little at first, but that kinda worked out for me since i was using it to make an impression stamp of rock. i think it helped to release it from the rock. still had to pry it off carefully. after a few days of wiping the mineral spirits off the mold, it seems to have stopped. could probably wash the access off with dawn dish detergent?
Would I be able to us Isomalt in this kind of mold?
If your using it for non-edible things like breakaway glass then yes but not for edible stuff. The thinner leaches and contaminates the food.