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>G'Day from Down Under,</p><p>So I've been scrolling through all of the suggestions and replies, yet not one mentions how long these molds will last? Different sites stated that their molds shrunk after only a few days, I also live in a hot-temperate zone so will the weather effect it at all? I am just beginning to teach myself to sculpt, at the moment I'm using salt-dough to get a feel for the craft and to push my abilities. I have managed to create the exact item that I wanted (no-one more surprised than self!!). It is still in the air-drying stage and I'd really like to create this image repeatedly as my signature piece. Can anyone advise me of a permanent molding recipe please? My main piece is 15&quot; x 1.5&quot; x 3.5&quot; (or, in Aussie speak: 30cm x 4cm x 9cm), it will be having extensions of varying sizes at a later date (like wings, branches, roots etc), it has a flat base and is intended to be hot-glued onto a canvas as part of a multidimensional artwork. I am still in toddler mode here (aka knows nothing!) and not sure yet whether the salt-dough will be appropriate or whether I will be progressing to the big girl's sandpit (I'm 55 years young!!) and using air-dried clay. I need for the result to be light enough to stay fixed to the canvas (any suggestions as to other more suitable material to use please stand forward!). I am unable to bake or fire the piece as it is just big enough to be too big to fit in my oven and I don't want to be stuffing around making half bits. I am VERY new to this field so please feel free to throw lots of well-meaning advice, I'm an Aussie, we eat well-meaning advice for brekky! Thanking you all in advance, your help is MUCH appreciated.</p><p>Erynne Baynes,</p><p>Queensland, Australia.</p>
<p>Great instructions except for the fact that the full instructions for molding the entire dinosaur are not included. I have made two-part molds from plaster for a largish art project using metal shims shoved into my soft clay original, but that does not work for a firm original like most of us want to copy. I, along with many others here would like to know how you personally make a full mold?</p>
<p>Heya, i'm along with you. i'd love a reply from the author, but I *believe*, and don't quote me on this, that the first mould, once cured, could have a thin coating of Vaseline or thinned petroleum jelly (thinned with meths or whatnot) and then the second layer of silicone could be placed over. Like, take an ice cream tub- one of the 2 litre ones, squidge your silicone into that and push your object into that up to the mould mark halfway. then, let it cure. put the Vaseline on, then fill the ice cream tub up to the rest. once it's dried, cut the plastic off and prise the silicone apart, giving a 2 part, if large and blocky mould. Take clay and make a sprue on your positive before casting if you plan on pouring into your mould. That's what i'm doing and it's worked for me, though I know very little about plastics. I'm sure someone will correct me, but I hope i've helped in some way.</p>
<p>Would this also work for making crayon mold ?</p>
Yup! I learned this technique so that I could make burn out casts from wax positives. Crayon away!
<p>How long does it take in the water bath to be ready? My first one fell into pieces, my second one seemed better but I'm not clear on the timing.</p>
<p>Great post! I'm a huge fan of this site. I would like to make cogs using HDPE milk bottle lids. the HDPE melts at 175 degrees celsius and needs to be compressed to get rid of any air bubbles. </p><p>Would the silicone be OK at that temperature and would I need to use a release agent? I've tried casting these cogs using plaster of paris but removing the HDPE ruins the mould. </p><p>Thanks!</p>
<p>I'm trying to add a silicone 'lip' to an existing dustpan, to make it pick up the little dust bits better. Do you think the silicone would attach? Should I score up the edge of the dustpan to make it adhere better? Should I put the silicone straight on, shape it, and let it cure, or use another method? (If there's a better place to be asking this in, please let me know!)</p>
The one part silicone that cures with moisture sticks to things, which is why it is used as a caulk. But cured two part silicones (tin or platinum) won't stick to any nonporous surface except the same type of silicone. While mold release will prolong the mold life; it is really only critical when casting silicone of the same type. Note that tin silicone inhibits cure of platinum silicones.
<p>Silicone sticks to almost anything, but polyethylene is almost impossible to glue to. Maybe start with a dustpan made of something other than polyethylene.</p>
<p>Hey, how about Sugru? Google it and check it out.</p>
<p>Silicone will stick to that dustpan no-prob. I would score it and clean it with alcohol first. If you need to shape it into a lip, maybe look at some <a href="">grout tools to help you get the shape right.</a> For this use case you could even use quickset silicone, and never mix it with water or soap.</p>
<p>I tried several times to make a mold from a ceramics figurine (unglazed) I made for the project. But the silicone always sticks way too good to the figurine, thus not leaving a very smooth mold. Also very hard to get out.<br>I never tried to cure it in soap water first, but do you really think that would make the trick? I tried to cover the figurine in oil first, but made no difference.</p><p>Now I just have a figurine with a lot of silicone residue all over it, and I can't figure out a way to clean it off efficiently so I can start over</p>
<p>Ceramic is a pretty porous material, even when glazed sometimes, and the silicone loves to stick to it for that reason. In my experience, using the soap water bath will not change the unfortunate results very much if at all. I don't know a good method of cleaning a silicone stuck figure besides burning the silicone off and I wouldn't advise using ceramic objects for this process, ceramic just doesn't want to play nice with silicone.</p><p> If you are still bent on casting it, you could maybe coat the ceramic figure with some sort of resin after it is cleaned to give it a less porous surface...? Something to look into perhaps!</p>
<p>I'm not too keen on getting it glazed, because I want to keep as many details on it as possible</p>
Actually, you don't have to glaze it. SuperSeal from Smooth-on seals porous surfaces and is specifically made for this purpose. It comes off with warm water.<br><br>https://www.smooth-on.com/product-line/superseal/
<p>Hi Mikki! I am an instructor for porcelain and ceramics (35 years) and I tell you that so you know I am not blowing smoke but know the mediums enough to give you help. You can glaze any bisque piece with 2 smooth coats of clear glaze and not lose the detail of your piece. Over coverage is where most folks lose some of the details but you will never be able to get a nice mold from a piece that is not smooth to start with. The mold only replicates what you have, and exactly as it is. You're mold will be so nice once you prepare your ceramic item correctly, and your pieces you pour will too! Good luck!</p>
<p>Mikki the trick to it not sticking to your ceramics is it needs to be a glazed piece. Not sure if you are using a bisque or plaster piece but it needs to have some kind of finish on it. Hope this helps.</p>
<p>'Contractors Solvent' by De-Solv-It will remove silicone. Available at most hardware stores, it is safe on skin and smells like the skin of an Orange. The solvent is then washed off with soap and water. Use a moisturizer after rinsing your hands as it will also remove your skin oils. I use it to remove tar and tree sap from clothing as well.</p>
<p>Ceramics as in heat resistant? Silicones are known to be almost in-destructable by chemicals (there are some nasty bases that actually dissolve silicone but nothing houshold-grade). Most silicones however start to degrade at 300&deg;C. You could try to put your figurine on a barbecue grill and see if it can burn-off the residuals. </p>
Its a stoneware figurine, so defiantly heat resistant, as it was burnt at 1250&deg;C :P<br>I'll try that, thanks!
<p>Have you tested a wax coating to prevent silicone sticking to the piece?</p>
<p>I have some beeswax, so I might give it a go. </p>
Seemingly silly question but how do you use this method to make a mold of the whole object? Like, I want to be able to have the tail of the dinosaur as well. How would I do that?
<p>This really works well. I have a brass windmill cookie mold and made stamp out of it.</p>
<p>This looks really interesting. I can never find the right moulds just when I want them so will definitely try this method.</p>
<p>100% success on this project. </p>
<p>silicone greese might be the answer! i have used silicone greese as a releasing agent for many concrete castings.</p>
<p>Its been 3 days and it still hasnt dried/cured when I take the figure out, am I doing something wrong?</p>
<p>Jus wondering how well the details are using this process and if I should use a release agent. The piece I want to replicate is made of resin and detailed.</p>
I spent a lot of money buying silicone tube but not yet
I spent a lot of money buying silicone tube but not yet
I spent a lot of money buying silicone tube but not yet
<p>Do you have issues with air bubbles in the silicone?</p>
<p>wow. And I have been spending $20 a pop for silicone molding putty at Michaels.</p><p>Thank you for this instructable.</p>
Is there a way to make some sort of silicone socks to cover steel table legs that are too sharp? Thanks
<p>I love this idea!</p>
<p>This worked for me in a slightly different use.</p><p>Collect wax paper, cut into the shapes you want your final form to be.<br>Apply silicone to the table foot, stick on the wax paper and form or mold it into the final shape you want. Let it dry, pull off the wax paper and you will see your silicone in exactly the shape you created.<br><br>Roll the wax paper around the siliconed led for a cylinder shape.<br>Or cut and box wrap around the leg for flat faces and bottom.</p>
Thanks, I'll try it immediately
That is so cool!!!!!!!
<p>I noticed in your ible that you didn't use any form of mold-release agent for your dinosaur figurine. Is it advised, or not really necessary? I want to make a mold of some resin pieces, but I know how sticky silicone can be. Removal of silicone would be a major pain if it didn't let go properly.</p>
<p>Not to be a negative nancy... But why not just use made-for-purpose silicon mold compounds? e.g. http://tiny.cc/ultrasil (aside from the 'use what you've got lying around' benefits of course ;)</p>
<p>My thought on that would be cost saving. Depending on the amounts you're working with this seems much cheaper in comparison. I've looked into some of the products similar to what you linked and they could be cost prohibitive for the hobbyist.</p><p>Certainly for small projects it's easier not having to mix two parts to the mold material from a larger bucket.</p>
<p>Are the mould flexible? I am hoping to use it for some concrete projects, and I think some flexibility would certainly help to demould. Thanks!</p>
<p>i want to make a mold of a large leaf, will this work and is it pliable?</p>
<p>really great idea for making wax positives for metal casting.. if you're making art projects you can turn out several small bits of add on decoration...and the ability to grab something off the shelf and use it on spontaneous rainy day projects with the kids is impressive. thanks for the ideas.</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>Rubber companies only submit one of their formulas to test for food safety - it's very costly. Silicones are considered safe, and I'd use them for home food use, but for commercial/restaurant use you could only use the tested/approved silicone.</p>

About This Instructable




Bio: I'm an Instructables success story! After relying on the site to DIY my way through art school, I was able to join the Instructables ... More »
More by audreyobscura:Beyond Beginning Breadmaking Great Photography Projects Watercolor Resist Cards 
Add instructable to: