I call it Oogoo, an inexpensive silicone clay that is easily made. It can be used as an excellent substitute for Sugru. It can be hand molded or cast in forms. Or, it can be used as a casting silicone. It can be colored any color from white to black. It can also be made translucent to allow diffused light to shine through. It can even be painted on in thin layers. It has very good adhesive qualities and will stick to itself, glass, fabric, paper, wood, and some plastics and metals.

This instructable will show :

1- How to mix and color Oogoo

2- How to cast it or hand form it into different shapes.

3- How to make silicone paint

4- Several interesting uses for Gorilla tape and Gorilla Glue, see steps 3, 7, 12 and 15.

5- How to make a few projects using Sugru and a comparison of Oogoo and Sugru

Since I am mainly interested in using Oogoo to embed electronic circuits in flexible forms, this instructable will also show you how to:

1- Make a soft circuit LED pumpkin head robot display that can be embedded on to clothing.

2- Make cleanly etched conductive fabric circuits

3- Make conductive glue using Gorilla glue.

4- Embed circuits in Oogoo or Sugru

The intro pic shows a few of the silicone shapes that I made using Oogoo and a funky, smirky, flexible pumpkin head robot LED display.

Step 1: How It Works

pic2 shows a 2"x2"x2" solid silicone cube that cured enough in two hours to be removed from its plastic box form.

For years I have been looking for an inexpensive way to create a flexible skin covering for robots and electronic circuits. I have tried several kinds of casting urethane rubber and silicone rubber. They all have their difficulties and either set up to fast or too slow. They are too thin or they are too thick. They are also very expensive in small quantities. Added to that is the problem that they have a very limited shelf life and usually must be used within six months. Sugru is great, but it is not affordable for making larger structures.

I and many others have tried using the inexpensive silicone caulk that is readily available from hardware stores. It is used to seal roofing and glass windows. It works fine but has the problem that it can only be used by putting it on thinly and waiting a long time for it to cure. It is also hard to work. It must be smoothed immediately while it is very sticky. Otherwise, the surface cures quickly and then forms a gummy film while the inside remains soft and wet. It has a smoothing time of seconds rather than minutes. If you put it on too thick the inside will remain soft and can take several days to finally cure. People have tried all kinds of additives in an attempt to make it cure in a more useful manner. I have found those additives to be unusable for my purposes.

So I wanted to add a catalyst that would help the silicone to cure from the inside out rather than just from the outside in.

As I understand it, 100% silicone caulk works by the moisture in the air initiating the polymerization of the silicone. So it cures from the outside in and as it does, it allows the water vapor to slowly seep inside and eventually cure the unexposed silicone. While it cures, it gives off Acetic acid (vinegar is diluted acetic acid) which is the strong smell you will notice if you use it.

I experimented with quite a few additives to try and introduce some moisture into the uncured silicone. Several of them worked to some degree, but the hands down favorite was also the least expensive.

It turns out that corn starch is highly absorbent and when sitting around in an open box it will absorb moisture from the air. It is an extremely fine powder that diffuses evenly in mixtures. By adding the right amount of corn starch, the sticky silicone is somewhat stiffened and very quickly starts to set up from the inside out. While it still sets up faster on the surface than in the middle, the whole thing will set up in five minutes to 2 hours no matter what the thickness. The actual curing time depends on the temperature, the humidity, the amount of corn starch added, and the speed at which it was mixed.

So that's it. Oogoo is corn starch and clear silicone caulk mixed together and then molded by hand or by forms to create just about anything you can imagine that needs to be adhesive initially and solid yet flexible when cured.

<p>Great stuff. I used it make a rubberized casing for some electronics. </p><p>I found it was pretty sticky to work with while wet, so my hand molding tended to leave the rubberization on the finished product looking pretty lumpy.</p><p>does anyone have any good suggestions for applying an even coating of it on a surface such as a metal housing?</p>
<p>Wow - great post! Thanks! <br>Question: Do you have a feel for how well this would survive over time inside a dishwasher? (I need to do basket repair)</p>
Already my first attempt was a full success - thanks a lot ?
<p>Great! I think about modelling a stop-motion-puppet... Oogoo could work over an armature ... Thank you!</p>
<p>This is, in a word, awesome. One more cool thing to do with corn starch. I can't wait to try it. I might go poor(er) buying tubes of silicone caulk, but I have simply got to try it. Thanks! :-)</p>
<p>On hackaday (see below) one person said they used bleach instead of corn starch. </p><p>Does anyone know if this is a good or bad idea? </p><p>Other than the normal dangers of working with bleach <br>(fumes, chemical burns, staining your clothes, etc.)<br>would this create toxic fumes or result in a more toxic plastic, <br>or have any different properties that might be useful <br>(such as more or less flexible, bendable or rigid, etc.)?</p><p>Much appreciated... </p><p><a href="http://hackaday.com/2010/10/11/oogoo-a-home-made-sugru-substitute/" rel="nofollow">http://hackaday.com/2010/10/11/oogoo-a-home-made-s...</a></p><p>&gt;&gt; Bob C. says: October 12, 2011 at 1:14 am</p><p>&gt;&gt; ...</p><p>&gt;&gt; I just made some of this stuff and used regular household bleach </p><p>&gt;&gt; instead of corn starch and a few drops of acrylic paint. </p><p>&gt;&gt; 2 drops of bleach for every full trigger pull of GE Silicone I, </p><p>&gt;&gt; it worked GREAT&hellip;</p><p>&gt; </p><p>&gt; Jerry Carter says:</p><p>&gt; August 28, 2013 at 11:04 am</p><p>&gt; Thanks for the alternate recipe! Sounds like bleach would </p><p>&gt; mix more readily than corn starch as well<br></p>
<p>I can't comment on the chemistry, but given a choice, I would go with the corn starch, for exactly the reasons you listed. I'd rather work with something I know is safe and non toxic and not going to harm me or the environment. </p><p>The only way to know if the bleach makes a difference, for better or worse, would be to try it. I have to disagree with the comment that it would mix more readily though. In such a small amount, it would be difficult to get it mixed evenly, especially when you can't see it. And 2 drops for every trigger pull is not really an exact measurement. How big of a drop? What happens if you get 3 drops instead of 2? Can the ratio be adjusted, as it can with the corn starch?</p><p>If you have tried it with the bleach, it would be interesting to know what the results were. </p>
<p>can someone explain why the silicone 2 will not work for this? It seems to be more easily avaliable to me, but I don't quite understand why it's different</p>
<p>I don't understand the chemistry, but Silicone II cures differently. It is a rapid cure caulk, and for some reason doesn't work well by adding other materials to introduce moisture into the caulk (which makes Silicone I caulk cure all the way through).</p>
<p>I was able to find the sil I caulk type after a couple stores, been a lot of fun expitimenting with this stuff!</p>
<p>Hello,</p><p>I am having trouble with the drying process. First off, I mix the cornstarch and caulk in a container until it is fully mixed. I continue to mix it, then I use my hands to start to shape it. At this point, the oogoo is very sticky and the consistency is not as thick as clay. I finish shaping it and it resembles clay and has a matte finish. It does degenerate when I push on it. I let it go for about 2 hours, and it still degenerates! It is not rubber at all! I used a 1:1 ratio. I was thinking one issue might be that I am working in a humid environment. I mix and shape the oogoo outside, but after about 5 minutes outside I take the oogoo inside for it to &quot;harden&quot;. PLEASE HELP!!!!</p>
<p>Make sure you are not using the &quot;Silicone II&quot; caulk. This is a quick-curing caulk that does not work well when you include additives like cornstarch. Instead , get the &quot;Silicone I&quot; caulk. It's cheaper too!</p>
<p>Are you sure you are using 100% silicone caulk? I tried it with some sealant we had and it wouldn't harden at all but that proved not to be the right caulk. With the 100% silicone there is a really strong acetic acid smell and that has worked every time for me.</p>
I see that you are having some trouble, and I am too. I tried something this morning though. I suggest before putting the Oogoo on the plastic molds, rub them in something that's liquidy and never dries, like vegetable oil. I'm sure that this will work. Just don't wash the oil off until after you take the oogoo out of the mold.
Of course, this only for plastic molds. I'm afraid I can't help with anything else.
<p>if your mix seems to act more like vaseline than putty it may be because the caulk you are using is too old. I learned that there is a shelf life on silicone caulk the hard way. recaulking the bathroom was no fun but at least the internets let me know that it wasn't a skill fail but a materials fail.</p>
<p>Regarding coloring the plastic, the last time I was at Home Depot, I looked in the paint department and could not find any linseed oil based paint.</p><p>Can anyone recommend where to find this, either online or at a national chain, and if so, a specific brand or product?</p><p>How would food dye, candy dye (which I think is oil-based), standard (ie non-linseed oil-based) oil paint (for example the kind in tubes they sell at an art store), or acrylic paint work in lieu of linseed oil based paint?</p><p>I would want a coloring agent that</p><p>1. is non-toxic &amp; safe for regular handling, kids, etc. (which is probably why they specify linseed oil based paint?),</p><p>2. will not stain things when wet (which I suspect something water-based like food coloring or acrylic paint might do?)</p><p>3. is not too hard to find or expensive (a nice to have, the above two requirements are the most important)</p><p>Any info appreciated!</p>
<p>Fine arts supply stores. I use Dick Blick and Utrecht Art, but there are many. </p>
<p>I've found that Alkyd (fast drying) oil paint, works very well.</p>
<p>Artist's paints for painting on canvas are linseed oil based. Michael's stores carry them as well as most independent art stores. Just a few drops is all you need.</p>
<p>apple-o, as far as I know, most oil paints are linseed oil based.</p>
<p>Not sure why that post is blank...?</p><p>Here ya go:</p><p>Has anyone figured out what to add to make oogoo harder, like Sugru? Maybe another additive, or simply the &quot;golden ratio&quot; of cornstarch to silicone etc.? The end product is great, but Sugru seems to be a little tougher, stronger once fully set. Thnx!</p>
<p>Maybe this is of some use?:</p><p>'The formulation of sugru contains 30% silicone caulk (polysiloxane) 20-50% talc, and the remaining additives including:<a href="https://en.m.wikipedia.org/wiki/Oxime" rel="nofollow" title="Oxime">methyltris</a> (methylethylketoxime) <a href="https://en.m.wikipedia.org/wiki/Silane" rel="nofollow" title="Silane">silane</a>, &gamma;-aminopropyltriethoxysilane, and dioctyltin dilaurate.'</p><p>~ <a href="https://en.m.wikipedia.org/wiki/Sugru" rel="nofollow">https://en.m.wikipedia.org/wiki/Sugru</a></p>
For sealing caulk tubes, I find sticking a large nail in the end of the tube works really well. Cheap, and reuseable, as long as you haven't cut the opening too large.
Hello, <br> For those that would like a pourable version ...use 1-1-1 parts of <br>100% silicon caulk (white or clear) <br>Corn starch <br>Naptha or paint thinner....Naptha will set faster but costs is a little more. <br> <br>I use this ratio to create molds to pour my fishing lures...like soft rubber worms..etc....it will stand heat up to 500 degrees. <br> <br>Mix very well....NO LUMPS.....this ratio will start to set in 40 min...and be fully cured in 4-5 hrs....I let mine set for 24 hrs before i put them in full use.
<p>How does the rubber compare to the putty version's?</p>
<p>I made some yesterday and managed to hang some pot lids up with it.</p><p>You can seal the caulk tube by removing the nozzle and laying some cling film/saran wrap over the hole, then screw the nozzle back on again to hold it there. Poke out the stuff stuck in the nozzle if there is any , so it can still be used.</p>
<p>I just seal the cartridge tube with a little of the silicone sealant, screw the nozzle back on, then put it back in the fridge.</p>
<p>Probably the preparing temperature and moisture are important, gelatinizing the starch could make sense!</p><p>Found an old Patent:</p><p><a href="http://www.google.com/patents/US4495226" rel="nofollow">http://www.google.com/patents/US4495226</a></p><p>Method for preparing silicone-treated starch </p><p>US 4495226 A </p><p>A method for treating starch with organosiloxane polymers is described in which the organosiloxane polymer is contacted with starch in an aqueous dispersion at a temperature of from 60&deg; C. to 98&deg; C. for a period of at least 60 seconds. Starch treated by this method can be useful as glue, a binder, a filler, or a coating. Starch treated with aminoalkyl- or epoxyalkyl- substituted polydimethylsiloxane is especially useful as a water repellent sizing for substrates such as paper and textiles.</p>
<p>I found you here:</p><p><a href="http://hackaday.com/2010/10/11/oogoo-a-home-made-sugru-substitute/" rel="nofollow">http://hackaday.com/2010/10/11/oogoo-a-home-made-s...</a></p><p>and besides the high price of Sugru this is the annoying point:</p><p>&quot;but one can&rsquo;t (yet!) just drop in on any local hardware store to buy a quick fix&quot;</p><p>So, good idea to test and probably improve!</p><p>:-)</p>
<p>Oogoo sounds funny</p>
<p>Wonderful instructable with must-have knowledge for the diy-selfer!</p>
<p> <br> <br>Excellent <br> information on your blog, thank you for taking the time to share with us. <br> Amazing insight you have on this, it's nice to find a website that details so <br> much information about different artists.</p><p><a href="http://www.monacopropertylistings.com" rel="nofollow">appartamenti a monaco</a></p>
<p>I am aware that it has been done many times, but I am wondering how well oogoo performs as a cord reinforcement. My old laptop cord has finally reached the end of its extended life (I have already rebuilt it once using super glue, heat shrink, and modable epoxy, and I nearly destroyed it in the process). Instead of waiting for my new-soon-to-be-heavily-used cord to wear out, I intend to reinforce it ahead of time. I have several questions:</p><p>1) Will the oogoo stick to both the cord and power brick?</p><p>2) The brick will be moved around a lot, will the oogoo wear down significantly over time?</p><p>3) I tend to be very fidgety. Can cured oogoo be easily shredded (and make a wonderful mess a the community college)?</p><p>4) Will the oogoo become hard enough to actually protect the cord?</p>
<p>Oogoo sticks to metal and plastic, but not real strongly. The more surface area it is in contact with the better it will stick. If there are rough surfaces or irregular surfaces that it can wrap around, it will stick better.</p><p>When rubbed it does not wear down easily.</p><p>It does not shred easily, but it can be sliced by sharp objects.</p><p>It will be hard enough to protect well if you can attach it well enough to not slide around.</p>
I have made this for a couple of projects. I thank you very much for the instructable. I have been using two plastic spoons and a shallow Tupperware container to mix it in and I really am happy with the re usability/ ease-of-cleanup those items give me. I simply let them dry and in a day or two peel all the silicon bits off and they are ready for the next project.
<p>Do you believe that the cornstarch contributes to the fast curing? Do you know of any other higher temperature tolerant fillers a person might use for say, casting pewter or eutectic alloys?</p>
Hello there mikey 77.. Im just wondering, if i put lets say about 2 to 1 cornstarch to silicone by volume, will the silicone absorb all the cornstarch? And i want to know if it is heat safe? Thanks for the great idea dude..
<p>hello can this method be used to make large molds for beeswax candles? I ve a ceramic ganesha I'd like to mold</p>
<p>Yes, it works well for molds for beeswax and other materials.</p><p>Test the Oogoo on the the object you are casting with a small patch of Oogoo.</p><p>See how well it sticks and how easily it peels off.</p><p>If it sticks too well to a porous object, you can spray the object with spray lacquer, as a mold release.</p><p>Apply the Oogoo, let it set up and then you can cast the beeswax.</p>
<p>Do you think adding epoxy to the mix would help it to be more rigid when it cures? It would be cool to be able to vary that based on how much you mix in. </p>
Is oogoo safe to use with foods? I.e. If you made a spatula or as the lid to a jar similar to the one you made. Also is it safe if a child got its hands on it and put it in their mouth?
<p>As I have said several times before, Oogoo is not food safe. So, you can add it to the list of things people, and especially children, should not put in their mouth.</p><p>If you want food safe silicone, you could try sorta-clear 40 silicone which is available from Smooth-On.</p>
If I'm using pure silicone aquarium sealant (which says that it is food/pet safe when fully cured) and food-grade corn starch, is there any reason that the final product wouldn't be food safe?
<p>Most likely, it would be food safe, but the only way to know for sure would be to run some tests.</p><p>One test you could try would be to do a test with the minimum of corn starch. Mix a batch of 3 or 4 to 1 of silicone to corn starch by volume. After it has cured, bury it in moist dirt for a week or two. look at it under a microscope for any signs of discoloration or mold. I have done this test with regular silicone caulk and found no evidence of mold after several weeks.</p><p>In my experiments most of the corn starch is internally embedded with very little on the surface of the cured Oogoo. You could try boiling the set up Oogoo in boiling water for ten minutes to dissolve any surface corn starch that could feed mold or bacteria.</p><p>That said, I would suspect aquarium sealant, if it smells like vinegar while curing, would be quite safe for storage of dry materials like coffee or powdered milk.</p><p>Hot liquid foods and moist foods might require further testing.</p>
<p>Oogoo catalyzed by corn starch vs soapy water bath? The latter being the less messy and easier method is now gingerly haning off my laptop as I type. I have been following the oogoo process for awhile now and happen to come across the soap/water bath rendering and decided to make the water immersion version since it a more &quot;pure&quot; rendering. I've taken a few photos and I'll update with the cured form as well. </p>
<p>Hey there! I tried making Oogoo just recently and it worked great but I was wondering about something. Is there a way to make Oogoo bond to surfaces by itself like Sugru could? Also, if I use less corn starch, would that help make the surface more repellent to sweat? I'm planning on making a mouse grip and would love to make this workout! Thanks and great instructable! :D</p>
<p>As I mentioned in the instructable, Oogoo does not bond as well to some plastics as Sugru does. You can try putting a thin coating of superglue or a thin coating of pure silicone caulk on the surface. Let it set up overnight and then apply the Oogoo.</p><p>If that does not work you can try for a mechanical connection. Use whatever glue will work on your surface to glue fabric or thin plastic mesh onto the surface. Once dry you can add the Oogoo.</p><p>I have not had any trouble with sweat on Oogoo. Clean it occasionally with soapy water and it should work fine.</p>

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Bio: I believe that the purpose of life is to learn how to do our best and not give in to the weaker way.
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