Yep. That's right. I am about to change your mold-making technique forever. This simple way of silicone mold-making will have you wanting to make casts of all your trinkets and toys.

You will need:
  • water
  • blue dish-soap (any brand seems to work)
  • 100% Silicone (do not buy quick set silicone, you need 100% silicone)
  • bowl
  • caulking gun
  • something you want to make a mold of.
  • scissors/knife
  • masking tape - to patch holes in your positive, if necessary.

Step 1: Make your catalyzing solution.

By mixing a high-concentration of dish soap with water in a bowl, one is actually making a catalytic bath for your silicone. The glycerine in the dish soap accelerates the cure process for of your 100% pure silicone.

This is by no means an exact science, I use blue dish soap because it allows me to see how much I have added to a water bath, I approximate that I used 4 oz. of soap in 64 oz. of water.
<p>Excellent article Audrey. I would suggest to your fans that they use nitrile gloves when handling the Silicone. I created my mold in ABS plastic made on a 3D printer and filled it with the silicone using your method. It worked out great! I sprayed Pam in the mold as a release agent, but doubt it was even needed as the silicone easily came off of the untreated plastic.</p>
<p>Does the small go away?</p>
<p>I know this is an old 'stble but here goes: I am working with glass making puddles using my microwave to melt the glass (could this be a topic for an indestructible?) and lately I have been casting things. Easiest for me so far is a mold for making sugar skulls which I have been using to make both positive and negative molds - the positives, being in Plaster of Paris, are usable as is and the negatives are made from high-temp casting material into which I stack glass.</p><p>Since I am pretty sure that silicone won't stand up to the temperatures, I was wondering if I should use the silicone to make the positive or the negative mold? Can it stand up to multiple uses as a positive? I have a hundred different castings of glass skulls and I want to find other items to cast. I do not like using PoP as a positive because it is too easy for the positive and negative molds to adhere to each other (I have ADD and find it difficult to monitor my molds closely enough to separate them).</p><p>Sigh!</p>
<p>Silicone will want to bond to silicone - you may need to coat it with a pretty serious mold release to get that to work.</p><p>Cool idea!</p>
<p>can you use this for food?</p>
<p>Not advisable, there are a few places in the comments where I talk about this not being a smart choice for food-grade use. Check out SmoothOn's food-safe molding materials.</p>
<p>What other materials/resins can you use the silicon mold with besides resin epoxy? </p>
<p>hot wax for lost-wax casting, tin foil for vaccuforming.... one time i mixed a bunch of sawdust with resin and tried to cast with that. It was cool...needed more glitter ;)</p>
Can you use it to make edible things?? Like if I wanted to make dinosaur shaped Jello or lollipops or something, would it be safe to bake or put things I'm gonna eat in it? Or would that kinda poison me??
<p>This isn't food grade silicone - and it off-gasses acetic acid as it cures. SmoothOn makes some really nice food safe Silicones, but make sure you get the kind that could potentially go in the oven.</p>
<p>Why use 100% silicone caulk? What happens if you use latex caulk, or latex acrylic plus silicone caulk? If using for cold process soap making, would anything other than silicone produce an undesired outcome?</p><p>Also, I would like to create a mold of a fancy soap I was gifted. Can I do this? Or will the wet silicone clay cause the soap to dissolve some? The soap is over a decade old, so it's had time to dry out a bit but still look just as pretty. </p><p>Finally, could spray foam be used, specifically for CP soap? Or would there be potential for chemical reaction?</p><p>Thanks for any help.</p>
<p>I see you asked this a long time ago. Make a run over to YouTube. There's a couple of people who use the latex. Look for Economical Silicone Making by papio68046. That's the better one of the two I've saved. I'd think this one would work better for the soap than the wet silicone. Good luck!</p>
<p>im a girl and i just want to ask if is it safe to make something penetrative (if you know what i mean) out of that 100% silicone?</p>
<p>If you're going to try this, I'd put a condom over the finished product. Better safe than sorry, and under the circumstances, you could be VERY sorry if it turned out unsafe! Happy trails :-)</p>
<p style="margin-left: 20.0px;">Hahaha this is hilarious and a very good question. I wish I could &quot;save&quot; comments.</p>
<p>go for it if you don't have any silicone allergies. Need a model? LOL</p>
<p>Hello Randy DIYer!</p><p>The silicone you are looking for is called 'platinum cure' silicone. It is the only type of silicone you should be using to find your smiles.It goes for around US$50 for 1 Kg. It is a two part liquid used in life casting ( and toys) and comes in a variety of hardness (Shore hardness scale). Truly love yourself ( and your friends) by spending a little more money for the safest material.</p><p>Have a fun journey with the best type of DIY. :) and spread the word DIY Dildos!!</p>
<p>Hey there - i feel like this is the question i have been waiting for since I published this Instructable. I'm pretty sure that this 100% silicone off-gasses acetic acid as it cures - it would just need to be neutralized before....well. have fun!</p>
<p>Hmmmm chcicks, + silicon = dildos. OK sex toys to masturbate with are a given.</p><p>.</p><p>My experience with acetic cure silicones, are to apply a primary coat to the inside surface of the mold, to design surface voids out of the rubber dong, and the vagina as acidic anyway... but which one/s make up the acid mix, and at what strengths - well acetic acid is not bad, it's an issue of strength and duration. </p><p>.</p><p>The issue with acetic acid curing silicones, is allowing TIME for the acetic acid to &quot;fume&quot; out of the rubber, so that the concentration levels / out gassing rates are so low as to be negligable.</p><p>.</p><p>Me thinks make the big rubber dick, and then when more or less cured, allow it to air dry over a week or maybe two, in a warm dry place, And then drop it into a pot of how water for an hour or so, to leech the residues from the surface.</p>
<p>thank you for the reply, one more thing. how can I nutralized it?</p>
<p>Maybe a baking soda bath? But this isn't medical grade tested - I would pursue further education about materials that may not irritate your skin. Or do some patch testing on your wrist of a neutralized cured silicone, at the very least.</p>
If I were to engrave something in wood and fill the engraving with this substance. Will it make a tough rubbery silicone mold for me?
<p>i advice you not to use on skin or (especially) anything penetrative, i&quot;m an artist and did many casts out of body parts which in such case i used alginate which is extremely safe and the results are super fine detailed.</p>
<p>Where do you find alginate? I am not near a Blick store, and I would prefer to purchase it in person...</p>
<p>I use to buy mine from my dentist - not sure if they even use the stuff anymore. I was doing life-masks in the late 80s. I bought it by the can - later a friend of mine found better sources.</p>
<p>http://www.smooth-on.com/Dragon-Skin%3D-FX-/c1339/index.html?catdepth=1. Dragon skin pro FX is completely safe for penetration. They also sell alginate that's safe for skin girlfriend loves what I made her Works great </p>
<p>Is this silicone safe to use for baking custom shaped cookies?</p>
This is so cool! What kind of led lights are used? How do you power them inside on the resin?
<p>Has anyone who has tried this method also used Smooth-On Mold Star? Smooth-On is very expensive, so finding an alternate would be great. But I'm wondering how this method compares as far as work-time and flexibility of final mold. I need to make a single part mold of something with a bounding box of about a 1' cube. So I will need to make a large amount of this molding material as well as need to cut it afterwards to extract the object and make a cast. Can anyone speak to the material's ability to be made in large quantities at a time, be cut after curing, and flexibility?</p><p>Thank you in advance</p>
<p>Hi Eddie,</p><p>I cant speak for Smooth-On Mold Star, but can guarantee whatever Smooth-on says a product will do,,,, will. Smooth-on is very helpful and never pushes sales after talking. ask for Charlie 1800-762-0744</p>
What difference will it make if I don't use 100% silicone?
I only have acrylic latex caulk plus silicone
<p>A lot of homemade silicone molds require 100% silicone. The additives (acrylic and latex) might interfere with the curing.</p>
<p>Can you reuse this mold, or do you have to make a new one for each cast ?</p>
Tried this and two hours later my mold is still really squishy and now it's tacky. Not sure what I did wrong.
<p>I tried this just the other night for the first time, it worked great!! It came out just like it said. Now I am having a problem coloring the resin. I bought the darkest color specifically for resin and its still too light. It gave me a baby blue and I need cobalt blue. How much of the coloring can I add before I mess up the resin? any other suggestions for alternative coloring methods?</p>
<p>I actually add acrylic paint to color resin. It turns out opaque, but its perfect if that is what you are going for!</p>
<p>Has anyone who has tried this method also used Smooth-On Mold Star? Smooth-On is very expensive, so finding an alternate would be great. But I'm wondering how this method compares as far as work-time and flexibility of final mold. I need to make a single part mold of something with a bounding box of about a 1' cube. So I will need to make a large amount of this molding material as well as need to cut it afterwards to extract the object and make a cast. Can anyone speak to the material's ability to be made in large quantities at a time, be cut after curing, and flexibility?</p><p>Thank you in advance</p>
<p>Hi and thanks for the instructions! I want to make a sugar mold by pouring boiling sugar into it. Any idea what materials I could use so that the sugar would not melt the mold?</p>
OMG, this was a perfect set up for what I needed. I proposed to my wife at the top of Empire Bluff in the Sleeping Bear National Lakeshore area in Michigan by carving Marry Me with our initials in a dead tree/drift wood. We visit every year and I have received it every time for posterity. I wanted to find a way to give her the carving for our 15th Anni since I have been carving it for that long. Your mold design was so simple that I secretly climbed the bluff trail with the materials in a backpack, completed the process at the log, and left the mold to dry overnight. I went back yesterday and got it and it a perfect negative of the tree. I can't wait to pour my resin and paint the piece to look like the log. Thank you so much for this instructable.
Hi I was wondering if this would be ok to use as a food mould? I was hoping to make a mould of Lego bricks and then use them for making cake decorations etc <br>Do you know if that would be ok with this method or if I'd have to find an other method? <br>
I'm wondering the same thing..
<p>It off-gasses acetic acid as it cures, it would have to be neutralized before using.</p><p>Here is food-safe silicone, I would trust this vs. my suggested technique.</p><p>http://www.smooth-on.com/Food-Safe-Material/c1387/index.html</p>
<p>I'm going to have to try this! I do have a question: can you sculpt this at all? It looks kinda soft, would I be able to let it set for a bit then shape it? I want to make a resin base with a water ripple pattern on top.</p>
<p>You can kind of sculpt it, I would say you have about 10 minutes of malleable time before it sets up and starts really curing.</p>
Hi there! Great idea and great instructable!! I've got two questions for you. First of all, you said it's clycerine the catalyzer. What if i use pure glycerine?? Aaaaandd... Most important thing.. Could common silicone be used to cast Silver?
<p>No, the silver would have to be to hot for the silicone. Silicone can cast things at temperatures around 200c. Silver melting point is like 800c or something high like that.</p>
<p>Great idea! Where is the second half of the mold, did I miss it or does Glitter-Trex have no tail?!</p>
<p>Could I mold a full object and then cut it in half with a exacto knife? </p>

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Bio: i work at instructables! i make things with technology, eat pho, and play electric ukulele.
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