How to Make Reusable Molds (CHEAP)

in this lesson I'm going to show you my method for making an inexpensive mold of this caricature sculpture of Stan [Music] preno for supplies I'll be using silicone 1 allpurpose 100% silicone clear culk some soft non-drying modeling clay a cutup t-shirt Vaseline some brushes plaster burlap cloth popsicle sticks some soapy water that I made with dish soap and some cheap clamps because we're using some cheap air dry silicone make sure that you're working in a well ventilated area some rubber gloves are also probably a good idea once the sculpture is ready to be molded the first layer is going to be the detail layer for this I use a cheap brush and add a bead of silicone and then lightly brush the silicone into the details be careful not to press the bristles into the sculpture because that might damage the details while you're brushing on the silicone keep this layer thin this is an air drying silicone so area that are too thick will not cure completely and that can ruin the mold sometimes as I'm brushing there's little hairs that come off the surface so I use some soapy water to smooth any of those out here's what it should look like once the first detail layer is complete once that layer is dry I'll take a dry erase marker and draw out a line that separates the sculpture from the front and back half I like to have this line go right through the ears so that the ears don't get caught on one side of the mold or the other when Dem molding I'll take a paint brush and brush on some of the Vaseline onto the wood base of the sculpture so that the silicone won't stick to the base later on in the process with this guideline in place I'll take some plasticine clay and build up a wall around the sculpture along this seam so this wall will be the seam of the sculpture that separates the front and back half so it should come off the sculpture a decent amount and if it's a larger sculpture then you can come off the sculpture a little bit more when the Wall's in place I'll take a sculpting tool and C clean up the texture of the wall of clay during each stage of the process I want to make things as smooth and clean as possible and that'll make a better mold here's what it should look like when the wall of clay is in place next I'll use this piece of cloth that I cut off an old blue cotton t-shirt this piece of cloth should be larger than what we need to cover the back part of the mold multiple strips of cloth can be used if you're doing a larger sculpture once the cloth is ready I bead a generous amount of silicone it's important to cover all of the back part of the sculpture completely as well as the wall of clay any dry areas won't adhere to the cloth and will cause weakness in the mold this can be a little bit tricky because the silicone looks exactly the same whether it's wet or dry so take your time and make sure that you've got full coverage I'll show you a little trick that can help differentiate the wet and dry areas when we get to the other half of the mold now I can use my hand to press on the cloth onto that wet silicone this cloth adds strength to the silicone and prevents the mold from tearing we you want this layer of silicone underneath the cloth to be quite a bit thicker than the detail layer of silicone so that it can fill in any of the wrinkles in the cloth as I'm pressing on the cloth I try to make sure there aren't any air bubbles or dry areas now we can add some additional silicone onto the back part of the cloth do this when the silicone underneath is still wet so that the silicone on both sides of the cloth can soak through the cloth completely again I'll use a popsicle stick to spread the silicone this colored cloth helps because it turns a dark blue as the silicone soaks through the cloth if there are areas like these wrinkles in the cloth I need to add some extra silicone and make sure that it soaks completely through this may take some extra time to work the silicone into those areas once the back is completely covered in silicone I'll dip my fingers in some of the soapy water and then press onto the surface to smooth things out and remove any strings of wet silicone depending on how thick the silicone is it can take a day or two to dry so I like to make these molds over a week or so and just work on it a little bit every day to give each stage of the process time to dry once that's dry I can remove the wall of clay then I'll use scissors to remove any excess cloth from the seam that I've built now I can add the key onto the inside part of the wall of the seam of the mold I like to do this by beating on some silicone at a slight angle as you can see here I make this continuous bead of silicone that goes all the way around the sculpture what this does is it creates kind of a teardrop shaped piece of silicone so that the other half of the mold can lock into that teardrop shape and prevent any leaks on the other side I beat out smaller teardrop shaped pieces of silicone these keys will help lock the back of the silicone mold onto the plaster mother mold if there are any hairs of silicone that I've created as I pull away from these beads of silicone I can again use my fingers dipped in soapy water to smooth those out before I work on the other side I'm going going to take some silicone and fill in some of the more detailed areas like the ears the eyes the mouth and smooth those out with my finger and soapy water this will prevent air bubbles from forming as I add on the next layers of silicone and cloth onto this front side of the mold at this point I take an exacto knife and cut around the detail layer along the seam or wall that separates the front and back halves of the mold this is just to help the mold come apart a little bit easier later on next next I take some Vaseline and brush it onto the silicone on the seam where I don't want the next layer of silicone to stick be careful not to get Vaseline on the front part of the sculpture and make sure it gets into the key area to avoid any tearing in the future when separating the two halves of the mold I said I'd show you a trick so something optional you can do is mix a little bit of food coloring into the silicone and this changes the color of the silicone and it also helps with the curing process C so if there are any thick areas that might take longer to air dry some food coloring mixed into the silicone can help that curing I'm adding the silicone onto the mold and then using my fingers dipped in soapy water to press it into the key area of the seam of the mold and onto the side of the face of the sculpture once that has time to dry I'll use some water to clean off any of the soap that might be on the front layer of silicone and make sure that it's dry before adding some additional silicone now I can bead on a generous amount of silicone on this side so I can add the cloth onto this half as well I'll follow the same process that I did on the first half making sure to eliminate air bubbles and make sure that the silicone soaks all the way through the cloth then clean it up with some soapy water again and add those teardrop shaped keys to this side of the silicone mold once that cures we can use scissors to cut off the extra cloth again leaving a clean seam then I'll take some Vaseline and apply it to anywhere that might have dry cloth because plaster will stick to dry cloth and make the unmolding process very frustrating now I take a box with some crumpled up newspaper and I'll put the sculpture down face up for this mother mold I started with placing some wet burlap directly onto the sculpture though you can do a detail layer of plaster directly onto this silicone part of the mold if you want to capture more details once the burlap is in place I add some plaster onto it and spread it around making sure that the plaster soaks through the burlap as much as possible I'll wrap the extra burlap around the sculpture and try to clean up the outside area around the seam I like to try to give a little bit of a lip along the outside wall so that I can use some clamps later on to hold the mold closed but you can also use rubber bands or bungee cords to wrap around the mold once this part of the mother mold has hardened I can turn the sculpture over and do the other half I like to add another wall of clay to make sure that the front and back half layers of plaster don't stick to each other then repeat the same process making the back part of the mother mold with burlap and plaster if you don't have burlap you can do this mother mold with just plaster the burlap just gives it some added strength and makes it less likely for the mother mold to break when you're separating the sculpture later on in the process next is the tricky part of separating the mold I use a butter knife to try to put it in the seam between the two halves of the mother mold and twist to the mold apart I also use my fingers to try to pull and loosen things up this is a tricky part because the mold can be quite difficult to separate and we definitely don't want to break the mother mold with some patience and work the mold should eventually come apart then I work to separate the two halves of the silicone mold by grabbing the piece of cloth and pulling them apart at the seam do this slowly and carefully and check inside the mold to make sure that it isn't tearing anywhere where you don't want it to if it starts to tear hair down the wrong place you can move to the other side and work at it from another angle or you can grab the xacto knife and cut in to guide the mold where it's coming apart if you've done everything right these two halves should come apart without tearing in the wrong areas then I like to use a butter knife or an xacto knife to clean up the mother mold and remove any sharp areas that could tear or cut the silicone later on I try to clean up the sharp edges inside the keys because these can damage the keys if if they're left too sharp once that's cleaned up I put the mold back together so that I can cast it carefully align the sides at the seam and make sure that it fits together accurately you can even add a little vaseline along the scene to help the silicone halves slide into place easier and keep the mold from leaking I like to use these cheap clamps that I got from the Dollar Tree to hold the mold together when casting I place it back into the box with crumpled paper to keep it in place and then mix the plaster it's better to mix a little bit more plaster than you think you'll need once the mold is filled about halfway move and turn the mold around to help get any air bubbles out and fill in the details of the sculpture here I didn't mix enough plaster so I had to quickly remix another batch and add it in once that is cured we can demold and see how the first mold came out if you're lucky there will only be minor issues like some plaster along the seam and some small air bubbles that'll need to be filled these are fairly minor issues and can be cleaned up with an xacto knife and some more plaster and water to wet the surface of the sculpture and then fill in any air bubbles with fresh plaster and there you have it from clay to plaster if you'd like to learn more about portrait sculpting I hope you'll get the full portrait sculpting course over at pra.com Portrait sculpt don't forget to like the video and subscribe to the channel if you'd like to see the sculpting process for this caricature sculpture you can find that on the main proo YouTube channel stay creative stay productive and I'll see you in the next [Music] lesson

Channel: Proko 3D

Views: 17,797

Keywords: sculpture, sculpting, mold making, molding, plaster mold, clay sculpture, silicone mold, reusable mold, plaster casting, sculpture duplication, sculptor, caricature, plaster copy, mold supplies, silicone caulk, modeling clay, vaseline, burlap, plaster cloth, plaster burlap, mother mold, mold separation, casting plaster, air bubbles, seam, sculpture details, affordable, budget, inexpensive, DIY, tutorial, beginner, intermediate, art techniques

Id: iJ35gRcoCdo

Length: 11min 15sec (675 seconds)

Published: Wed Nov 01 2023