# Moldable Silicone on the Cheap (Oogoo)



## TheOneAndOnlyKelly

I found this Instructables a little while back on making your own homemade version of Sugru. The author calls his version "Oogo".

Sugru is a pliable, waterproof silicone coating that comes in little packages. When mixed, it can be used to create little items, coat surfaces, and more.

However, I am _cheap_ and did not want to pay the price they are offering, so that's where the Instructables comes in.

The idea is to use the Silicone that comes in tubes (available at hardware stores, walmart, etc) to use for molding. However, regular silicone has some set time issues. Straight out of the tube, the silicone that is not exposed to air/moisture will not set for a long time (ever, if thick enough).

However, by mixing in corn starch (and a little paint if you want to color it), you can control the set time. Mixing at a 1:1 ratio, you have a couple minutes of workable time. After a couple more minutes, it becomes claylike. In 10-15 minutes it takes its final form and can be demolded safely. Using less starch will extend the working time. 5:1 cornstarch gives you about 2 hours, according to the article, but I've not tried that myself.

I've used this to cast ears from my model (my daughter). I did an impression with dental alginate of the ear, then packed the mold with the Oogoo and got some good results. I used popsicle sticks to manipulate the Oogoo when it is pliable (it is very stickly), packing it into the alginate.










After 10-20 minutes (I'm conservative about set times), I was able to easily demold the impression. The set Oogoo is very pliable and I would have no issues with using a plaster mold in the future without fear of breakage.










Had a gap in the above image on the edge of the ear. Also on the above picture I had cut the mold for when I tried casting plaster in the alginate. I did another impression of her ear using just the Oogoo and did not need to cut the mold or even need any type of mold release.

This stuff is easily colorable too when mixing it up. The author of the instructable recommended using old-based paints, as water will trigger the set process of the silicone, but I was able to successfully use water-based paint. That being said, when I mixed in the paint, the Oogoo was less pliable initially, I might want to use less corn starch when I color in the future.

You want to use the Silicone I type of silicone. Silicone II is available at stores and apparently it is not the correct time. Not sure of what would happen.

There is a strong smell of Acetic acid that is released by the silicone (vinegar) so you might want to be well ventilated. I did get a headache after doing this in my kitchen and it sting your eyes a bit, but nothing we all haven't had to deal with doing other projects, I'm sure!

I wanted to pass this along to fellow haunters to use and enjoy. I've seen this type of silicone being used to create fake wounds before, and this might make that process easier as well. :jol:

TLDR: Silicone I + Corn starch = quick and cheap silicone casting substitute.
Enjoy!


----------



## Jaybo

Very cool! I've actually been playing around with casting in paper mache clay. I have a couple of items I have already cast. Very cheap and very easy to do. Right now I am just using old plastic skulls and masks as a mold for the paper mache clay. I can see using this to make small silicone molds. Nice find! I'll post a video of a few items I have cast in paper mache clay in another thread so as not drag yours off topic.


----------



## Allen H

I love this stuff, Ive been making ears and fingers and such out of it, Indestructables is a great resource if you can sift through the lot the find the gems.


----------



## IMU

I've never added any corn starch to my silicone when mixing with paint. I too have had success with latex paints but don't do a 50:50 mix ... more like a 75:25 siliconeaint. Thanks for the info!


----------



## pennywise

Ferb, I know what we're gonna do today! Sorry, my kids watch Phineas and Ferb a lot. Anyway, I have been looking for something like this for a long time. Thanks for sharing!


----------



## TheOneAndOnlyKelly

*The Brain:* Pinky, are you pondering what I'm pondering? 
*Pinky:* I think so Brain, but burlap chafes me so.


----------



## pennywise

Lmfao!!


----------



## GhoulishCop

I used this technique tonight and it worked great! I did one thing different, though, in that I added naphtha to the silicone first which made it more "liquid" when it was mixed together. I used a ratio of about 4:1 silicone-naphtha. Allen H from StiltBeastStudios used naphtha when making a silicone mask. He was then able to paint it onto his form with a brush.

I then mixed in the corn starch (also at a 4:1 ratio) using a popsicle stick and smoothed out the top. I pressed my form into the mixture and within about 15 minutes or so it had cured enough that I could pull out the form cleanly.

I actually used plaster to cast the form, but intend to follow up with homemade paper clay (blown insulation variety). The plaster seems to take longer to cure in the silicone than it might otherwise but it captured all the details.

Rich


----------



## TheOneAndOnlyKelly

Does the Naphtha make it a little more toxic to be around? This stuff is an irritant to begin with....


----------



## RoxyBlue

Here's a link to a material safety data sheet for naphtha:

http://www.collectioncare.org/MSDS/naphthamsds.pdf

Hazardous and highly flammable as well. It's a nasty chemical when used with a lack of attention to safety precautions.


----------



## heresjohnny

Resurrecting this thread. I have been looking for a way to try and mold arms, heads and torso's for ghost kits, and I think this is worth a try. I have some questions for those of you who have tried this. How large a mold can you make with this? Has anyone ever made a mother mold on one of these? Can it be painted or smoothed on the armature without it all running off?

Thanks!


----------



## Sytnathotep

I am also intersted in knowing how well this worked out. I'd like to find something cheaper than Dragon Skin, with the caulk this requires at $5-6 buck for 10 oz, and the Dragon Skin $30 for two pounds, it would work out to about half the price....if t works and is worth the hassle.

I have been considering giving this a try, already got the stuff, just need the time. I was going to experiment by attempting to use it to mold a normal sized pumpkin. When I give it a go, I will most definitely post my findings!


----------



## pennywise

I tried this and it works great. The mold dries very fast. Another method that I like is to use the silicone straight out of the can. You dip your fingers into a cup of soapy water and then press/spread the silicone around and it won't stick to your fingers. I used the fiberglass resin and fiberglass mat from the automotive dept at Walmart to make a mother mold. My first attempt at filling the mold with great stuff didn't work out since I didn't fill it all the way, but I'm going to de-mold today anyway to see how easily Great Stuff comes out of it. Here is a link to where I learned the soapy water trick...


----------



## Lord Homicide

Sytnathotep said:


> I am also intersted in knowing how well this worked out. I'd like to find something cheaper than Dragon Skin, with the caulk this requires at $5-6 buck for 10 oz, and the Dragon Skin $30 for two pounds, it would work out to about half the price....if t works and is worth the hassle.
> 
> I have been considering giving this a try, already got the stuff, just need the time. I was going to experiment by attempting to use it to mold a normal sized pumpkin. When I give it a go, I will most definitely post my findings!


I was going to mold a pumpkin too. Let us (me) know how it goes, heh

I'd like to be able to go to a store and buy the materials for this instead of order stuff off the net. Also it's probably cheaper too.

I'd love to test it out on a skull I have to make these


----------



## pennywise

The mold worked great for me. I used Great Stuff to cast the skull. The only problem is that the foam deep inside hadn't cured yet and the skull caved in when I removed it. Other than that it worked great. I am going to buy more Great Stuff and try again in a couple days.


----------



## Lord Homicide

pennywise said:


> The mold worked great for me. I used Great Stuff to cast the skull. The only problem is that the foam deep inside hadn't cured yet and the skull caved in when I removed it. Other than that it worked great. I am going to buy more Great Stuff and try again in a couple days.


Seems like you'd have to drill small vent holes all over the side opposite of the mold opening to vent. Then carefully trim the foam noodles off. Surely you remember trimming off the plastic from injected molded parts lattice for model cars.


----------



## Bone Dancer

pennywise said:


> The mold worked great for me. I used Great Stuff to cast the skull. The only problem is that the foam deep inside hadn't cured yet and the skull caved in when I removed it. Other than that it worked great. I am going to buy more Great Stuff and try again in a couple days.


When GS is to thick the middle can not get the moisture it needs to cure. You might want to try one of these options. 
Mist the mold with water before you put the GS in and again half way through.

Place something in the middle of the skull that can be removed as the GS is curing. A small drinking glass with smooth outer surface that has been covered with a release agent (vaseline ect) This will help to prevent the gooie center problem and make a hole that can be used to mount the skull.


----------



## pennywise

Thanks for the tips. I like the idea of added something in the middle. a balloon perhaps? They are very cheap (25 for $1 at Walmart) and can be deflated and removed. I will also try misting it with water. I did make a successful cast with hydrocal, but it's heavy and I intent to use it for a sculpting armature


----------



## Cragun

*Applying oogoo prosthetics to skin.*

How can I apply a prosthetic made of oogoo to skin. Would spirit gum work?


----------



## Allen H

Cragun-
Please dont apply Oogoo to your skin. Tin cure silicone has industrial solvents in it and will slowly attack your liver. Try to wear gloves when you are using it. Even when cured it still leeches chemicals. Platinum silicone is used for make up, not tin cure (caulking silicone).
Use Gelatin to make a prosthetic instead. I will do a tut video soon, but it is super easy. There are also a few videos out there that are good.


----------



## pennywise

Been awhile, but I made a second attempt at a Great Stuff skull. I tried misting the mold with water and then again about half way through. When demolding this time I noticed the foam did not expand enough to get all the details of the skull, which isn't a big deal since the skull is going to be skinned with Allen's Corpsing With Caulk tutorial.

The issue with the foam this time was that a few days after I removed it from the mold, it shrank, causing the skull to deform which looked cool, but isn't what I was looking for. I think the best suggestion would be to insert a soda bottle coated with Vaseline. Going to try it out again when I get a chance.

@GhoulishCop, I was wondering if I mixed the naptha and corn starch in with the silicone if I could spread it on with a spatula. If so, my friend and I could knock out a bunch of skull molds in a couple hours.


----------



## Allen H

Pennywise, another option for your skulls is gorilla glue. Mix the gorilla glue with just as much water, then paint a layer into your mold. Comeback in half an hour and pull out a skull.


----------



## Sytnathotep

pennywise said:


> Been awhile, but I made a second attempt at a Great Stuff skull. I tried misting the mold with water and then again about half way through. When demolding this time I noticed the foam did not expand enough to get all the details of the skull, which isn't a big deal since the skull is going to be skinned with Allen's Corpsing With Caulk tutorial.
> 
> The issue with the foam this time was that a few days after I removed it from the mold, it shrank, causing the skull to deform which looked cool, but isn't what I was looking for. I think the best suggestion would be to insert a soda bottle coated with Vaseline. Going to try it out again when I get a chance.
> 
> @GhoulishCop, I was wondering if I mixed the naptha and corn starch in with the silicone if I could spread it on with a spatula. If so, my friend and I could knock out a bunch of skull molds in a couple hours.


I've had the exact same issues with the Great Stuff for casting skulls like this. I'm still a strng believer in Smooth on's Foam it! line, great results every time, and cheap for how far it will go, but I will have to give AllenH's glue idea a go some time.


----------



## GhoulishCop

pennywise,

While I haven't tried it (yet) myself, that seems like a distinct possibility for making a quick and easy skull. Allen's idea for using Gorilla Glue is interesting, but it's slightly more expensive I think only because the glue itself is, though you're probably not using all that much.

Have you seen mystang's tutorial on using milk jugs to replicate skulls? You get a lot of detail out of them and you can't beat the price: free, if you're drinking milk already (one gallon water jugs work too, and they're cheaper!). Following up on mystang's post, I did a video tutorial of it too:






And here are a couple of pics of skulls I made recently using the technique. The second one I ended up filling with Great Stuff just to see what would happen and to give it some support. Worked really well.



















Sorry that my post here takes the thread away from the OP's original post on using homemade oogoo -- which, as I've noted before, I've used with great success (I did use my "Monster Clay" recipe with it to churn out pieces and it worked great!) -- but I wanted to address the questions being asked on here about making skulls, which then morphed into this technique. My apologies. :jol:

Rich


----------



## pennywise

GhoulishCop, those skulls look great. I have been trying the milk jug version too, but it sometimes seems to take forever. I'm still refining the technique to get the results I'm looking for. I will definitely try the gorilla glue method as well. Seems like it would be a pretty quick way to get skulls. Doing another on the milk jug today and if I can find my gorilla glue I will try that as well. I will also check out the Smooth-On site for the foam Sytnathotep mentioned. We need a lot of skulls and corpses for this year's haunt so whichever methods work fastest as cheapest...lol Thanks everyone.


----------



## GhoulishCop

pennywise,

_"I have been trying the milk jug version too"_

Uh, yeah. I forgot I was having a conversation with you over on that thread. Damn Alzheimer's is beating my ass today.

Rich


----------



## pennywise

No worries


----------



## pennywise

OK so Gorilla glue only costs $4 at Walmart, If I can get 2-3 skulls per bottle, the cost is well worth it. Trying the technique soon


----------



## Lizzyborden

Have the supplies to do this but wondering if I would need a release agent? Really wanting to cast a Walgreen's skull for my first project.


----------



## pennywise

Silicone doesn't usually stick to much. However, A couple months ago I tried silicone caulk over a couple resin skulls I bought at Walgreens. Not sure if I let it sit too long or what, but the silicone is still stuck to the skulls and I can't easily remove it. I had no problems with it when I molded a plastic skull though. I guess it wouldn't hurt to spread a thin layer of Vaseline over the prop first, just to be sure


----------



## craigfly06

Are you guys talking about mixing the silcone with that naptha? or just the oogo when molding a skull?


----------



## Lizzyborden

pennywise said:


> Silicone doesn't usually stick to much. However, A couple months ago I tried silicone caulk over a couple resin skulls I bought at Walgreens. Not sure if I let it sit too long or what, but the silicone is still stuck to the skulls and I can't easily remove it. I had no problems with it when I molded a plastic skull though. I guess it wouldn't hurt to spread a thin layer of Vaseline over the prop first, just to be sure


Thanks, I'll try the Vaseline. I had a similar experience using spray foam in a plastic mold. Used a release agent and still picking bits of foam out of it


----------



## Lizzyborden

craigfly06 said:


> Are you guys talking about mixing the silcone with that naptha? or just the oogo when molding a skull?


I'm just interested in using oogoo for now.


----------



## dudeamis

hmm, I think I might wrap one of my unpainted mache pumpkins with gorilla tape and make some hallow copies for masks. how flexible is this when its dried?


----------



## Lizzyborden

OK. After much procrastinating and intimidation, I finally tried this this evening and am quite impressed. 

First I filled in some of the cavities with modeling clay and then I used a 2" paintbrush and "painted" a thin layer of petroleum jelly over a Walgreen's skull. I then mixed up a small batch of oogoo and started with the facial area. Can't really say what ratio of cornstarch to silicone I was using, but my first batch was pretty stiff and set up pretty quick. I only made up a small amount at a time so I would have plenty of working time.

It was dry to the touch within a half-hour and within the hour I had it removed from the skull. There were a few areas I thought were too thin, so I put it back on the skull and added some additional oogoo. 

The petroleum jelly worked great! I had no problem with the oogoo sticking to the skull. I also found that if I rubbed some petroleum jelly into my hands, the oogoo didn't stick to my hands.

I'll try to post some pictures within the next few days.


----------



## discozombie

I messed around with oogoo and its fun stuff, easy to make, makes great molds and even casts well. I could do without the stink though. Plan to use it as toxic waste. I added neon green craft paint and it glows great under black lights. I also tried to embed a UV LED in a ping pong ball size goo ball but its too dense for the light to make it glow.


----------

