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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.
is the mold hard?
The 2 part castin craft epoxy resin I use isn't curing completely in my molds. I made mine 2 days ago and they stiffened perfectly and took the shape of my positives just like the tutorial said, but they continue sweating that harsh vinegar scented fluid. Has anyone else had this issue? I don't know if i should toss them or keep them a bit longer to see if they'll stop releasing the fluid.
If you wanted to mold the whole object, is there a way you could slice it in half while it's close to the end of curing so you don't half to have any part exposed?
can u mold metal in it?
<p>Not safely. Depending on the metal you're using, you most likely will want to use a sand casting method. There are tons of examples out there on Instructables and YouTube. There are some formulations of silicon casting that can be done with low melting-point metals (like lead), but the moulds need special preparation and additional safety measures to avoid being quite dangerous. Without testing this formulation under expertly controlled conditions first, your best bet would be to stick to safer methods when working with molten metal.</p>
<p>This has not yet worked for me.</p><p>I have 100% silicone.</p><p><a href="http://www.homedepot.com/p/GE-Silicone-II-10-1-oz-White-Window-and-Door-Caulk-HD5010-24C/100663324" rel="nofollow">http://www.homedepot.com/p/GE-Silicone-II-10-1-oz-...</a></p><p>I've tried more soap, but it doesn't seem to help, the silicone doesn't want to cure. Am i kneading it too long? i've tried more soap, as well as less silicone per kneading, but it doesn't seem to help. my guess is that im using the wrong silicone?<br><br>my current silicone patties have been trying to dry for 4 days now and are still tacky to the touch.<br><br>any advice?</p>
<p>Silicon II has added stuff to it. I haven't tried this Ible but I know for a fact that Silicon II is different in it's properties then regular Silicon. Silicon II is considered a fast drying Silicon in the construction field. Anything that says &quot;rainproof in X amount of minutes&quot; is going to be a faster drying and not pure Silicon.</p>
<p>am i kneading it in the bowl too long? this hasn't worked for me once yet. I've tried more soap, I've also tried less amount of silicone.</p><p>my only guess is that it is because i'm using white silicone caulking? the tube says 100% silicone though...<br><br>the silicone becomes kneadable and i can form it into a patty, but it stays forever tacky and doesn't seem to want to cure. the pieces I have laying out on the table have been drying for 4 days now and are still tacky.</p><p>any advice would be helpful. thank you!</p>
<p>hello! I've used this method many many times and have never had this issue.my guess is that it's he white caulk as opposed to clear. That's the only thing I can think of. In my experience, you can be pretty lenient with the amount of soap used, so I doubt that's it. Try getting clear caulking and tryi again. Good luck!</p>
The clear worked like a charm. Exactly how the tutorial says. I even get away with using minimal soap, about half as hot glass. But I wouldn't do any less.<br><br>https://jet.com/product/detail/aea652cc912a40b69a053a832922ddc1?jcmp=pla:ggl:cwin_hardware_a3:building_consumables_protective_coatings_sealants_a3_other:na:na:na:na:na:2&amp;code=PLA15&amp;k_clickid=1b3e8ed4-dcce-465e-af13-b7a0290cd844&amp;abkId=403-907727&amp;gclid=CM-Yl9O6w8oCFQuLaQod6xICpA
<p>Works great! Don't work it too long in the bowl, make sure you apply vaseline first if you need it. </p>
<p>is it able to be hand molded and is it flexable when cured? i wanted to make a mask and what is the difference between siliconized acrylic caulk and normal silicone</p>
This worked pretty well. Mixing the silicone was fun. I made a dice mold. Thanks for posting this.
<p>Great Mold Tut, thank you!</p>
<p>If it's the glycerine in the soap that's the active component, couldn't you just use glycerine? It's readily available.</p>
<p>I was wondering how much heat this mold will hold up to. I am trying to make something out of aluminum, and I have to heat it to about 300 degrees. Will this work or would I need something more heat resistant?</p>
<p>yes!! another completed mold, love this method Thank You :)</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>would this mold making tutorial work if I wanted to make a mold for some ear gauges ?</p>
Is silicone safe? I would like to make a mold for melt and pour soap. Would this hold up to the heat? I would like to use this, I'm just unsure about how safe it is to use. And I don't think my mom will let me use it unless I know for sure. Is it safe ones dry? Thanks.
If it is 100% silicone it is skin safe once it is cured,so you shoukd be fine using it to mold soaps. I am a proffesiinal face and body painter and paibters have been using it for years to make gem clusters to glue onto painted designs. Hope that helps.
<p>Hi :) I FINALLY MADE IT!!!, Thank You so much, took two goes at it and got it the second time, the mold works well. I was wondering if there is any difference in using white or grey silicone?? As here in New Zealand clear silicone is not cheap.</p><p>Thanks again Sandz</p>
Thank you for this! Buying mold making materials in my corner of Japan is nigh impossible ($140 for dragon skin, really?!) and I have been making little things again, so this is just the thing!<br><br>Do you, or anyone seeing this, have any idea if this will work okay with UV resin? And also, is there good detail with it, or does it lose a lot in the process?<br><br>I'm intrigued because it's clear, but just thought if ask before biking to the hardware store and getting more odd looks ;)
<p>Hi! I really want to try this to make mold to use when Im making soaps. Will this mold hold up with heat?</p>
<p>how stiff will the mold be once fully hardened? I plan on making replica 25mm cannon shells for decoration, and since they have some deeper ridges I want to know if I will have to cut the shell out of the mold if the mold is too rigid. </p>
<p>Thanks for the tuto! Question, can you reuse the mold multiple times? and do you have to use a releasing agent when you use the mold with resin?</p>
<p>If you do not place a silicone based item inside of the mold, you do not need a release normally. I use my molds until they break apart, but that is usually because I am really mean to them. I can cast about 50 things before I break them. LOL</p>
<p>I made the mold and when I poured my resin in it, it stayed sticky. Is there anything I can do to avoid this, or anything I may be doing wrong?</p>
<p>You have to allow the silicone structure to fully cure for at least 20-24 hours before you can put resin into it. If you live in an area where there is a lot of humidity, it could take much longer before the silicone mold is dry enough to use. I have this problem with the soap and silicone molds. They are easier to make, but the moisture takes so long to cure. You can try the method that uses cornstarch. I find this one works better in higher humidity areas. </p>
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>
<p>You should be able to find food grade pre-built lego molds online </p>
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>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>
<p>Almost everything could use just a little more glitter.</p>
<p>This looks amazing Audrey, I can't wait to have a go, the Blue dawn dish soap is not readily available here in NZ, so I'm hoping ordinary dish soap will work &amp; it works too as silicone tubes are not cheap here either. wish me luck, if it works I'll do the made it button :) Cheers Sandy</p>
<p>Any cheap bright colored dish soap should do the trick - the only reason I suggest colored dishsoap is so that you can visibly see the concentration of your soap/water solution.</p>
<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>Im about to refresh this Instructable with new images, and maybe a video so that I use the proper PPE, I've learned a lot since I've published this in 2011 :)</p>
<p>cool!</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>
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>
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?

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