How to make a 2 part mold! Cosplay Sword Casting

Hey guys, it's Kimpatsu Cosplay here and in this video tutorial I'm going to be showing you guys how to create a two-part mold in order to create really cool replicas and casts of a single prop. With a two-part mold you guys can create swords like this again and again using various kinds of cool materials. If you guys would like to see more tutorials like this every month you can join us on Patreon or you can check out our website where we have tons of cool cosplay resources and tutorials and patterns. You'll need a big flat smooth surface to create your mold on top of. I'm using a large plank to create the mold for my sword. You're also going to need some supplies to make the mold itself. You'll need a scale, a mixing stick, some gloves to protect your hands, silicone to create the mold itself. I'm using Amsol 25, a mixing pot to put the silicone into and clay to help create the base of your mold. You'll also need whatever you're planning to make the mold of. For us we're making a Mordred and Artoria sword from Fate. So we've 3D printed these swords and cleaned them up and now they're ready to be molded. I've already made half the mold for my Excalibur sword so now I'm going to show you guys how we get to this step using the Clarent sword here. So the first step when making a mold of our sword is that we need to make sure that the blade is sitting completely level. The blade of the Clarent and the hilt of the Clarent are not the same thickness so we're going to have to add a little bit of support under the blade itself so it sits level with the hilt. To help raise the blade I'm just using a piece of one centimeter thick EVA foam, cutting it into shape and then sliding it underneath. We only want to mold half the sword so we're going to have to build up to the midpoint of the sword with some clay first. The clay I'm using to do this is an oil-based clay called plasticine. So I'm going to take chunks of the plasticine clay and start to roughly build up how much I want around the parts of the sword. I'm trying to leave about four to six centimeters around my sword to create the mold so it's nice and strong and has a thick base. The height of the clay just needs to go to the midsection of the sword so if the sword got cut all the way down the center that's where the height of the clay needs to stop. Once you've got as much clay as you need around the sword we can start smoothing it out and pushing it all the way to the edges so that no silicone leaks through. To help smooth out my clay a little bit I just used my hair dryer and lightly went over the clay so that it was warm and easier to smooth and press into place. Making this clay base section is the longest and most difficult and annoying part of the whole mold making process but it's really important to ensure that you get a nice clean mold that won't hook and will fit together really perfectly. Once I finished generally smoothing out all the clay I try and use some sculpting tools to get the very edge by the sword as perfect and as neat as I can. This will ensure a really clean edge on your cast later. I'm just taking the tool and pulling it carefully and slowly along the side of the blade removing any extra clay that may have peaked up to form a lip. Now that the base of my mold is smooth and perfect I'm going to add in some keys. Keys are really important when it comes to molding because it's going to keep your two pieces together and make sure that they don't misalign when you do the casting later. I like to use something with a smooth round end to create my keys so I'm using a paintbrush and the end of a pen for this. So I'm taking these and pressing them all over the clay to create small holes which are going to create the keys for my mold. The edges of my clay at the moment are really rough so I'm going to be taking a craft knife and cutting off any excess clay around the edges and making them really smooth and neat. The final step in creating the base of your mold is to create some air chambers and a pouring hole. The pouring hole is exactly what it sounds like. It's a hole that you have to leave at the top of your mold or wherever you're planning on pouring in your resin when you proceed with the casting process. I'm putting a big chunk of clay at the very top of my hilt which is going to act as my pouring hole when I create my mold. If you're making a mold of something that's got weird corners on it where air can potentially get trapped inside the mold and no resin will fill when you pour it in, you'll need to create air chambers. Air chambers are small tunnels inside the mold that will allow air to escape as you fill the mold with resin. The chambers allow the air to escape so that there is no trapped air inside creating big holes and gaps in your casting later. For my swords I'm putting two small air chambers on either side of the hilt corners. I'm just using two pieces of straw to do this and forcing them into the clay making sure they're pressed right against the sword. Now we need to build a wall all the way around the base of our mold to contain the silicone that we're going to pour in to create the mold itself. To create my wall I'm just using some scrap one centimeter thick EVA foam and cutting strips and using hot glue to glue it to the board and all the way around the edge of the mold base. When gluing two pieces of foam together you can also use some hot glue to try and fill the gaps to make it completely watertight. You do not want any silicone being able to leak out of the walls so you want to get it as watertight as you can and make sure that all the corners and all the edges have been sealed with hot glue. If there are spots where the clay is not touching the foam wall you can just push the clay against the wall to make sure that it seals properly. I'm using some mold release called Ease Release to spray over my mold base here to ensure that my silicone doesn't stick to the walls of the foam or the prop itself. Now we're going to start mixing our silicone. So as I mentioned earlier the silicone I am using is called Amsol 25. Amsol 25 is a two-part silicone. It means that you need to mix two parts together in order to get the silicone to sit. It's 100 parts A to two parts B so it's a two percent mixing ratio. It takes 24 hours to cure but you can decrease the cure time to about 18 hours by mixing three percent instead of two percent. So we measured out our part A mixture by weight into a large mixing tub. The part A mixture is a really thick white liquid. Then we measured out our part B which is two percent of that part A mixture. The part B mixture is a very thin green liquid which will activate the silicone. Once both parts of our silicone mixture were measured and weighed we then poured the green mixture into the white mixture and began to slowly mix and stir them together until they were completely combined. It's really important that you mix the silicone very well. If any parts of the mixture were not mixed correctly or there are some parts of the white still remaining it will not set properly so you want to ensure that the entire mixture is one consistent color and that all the parts have been mixed together properly. We like to scrape all the way around the sides of the bucket and at the bottom to ensure that all the white parts of the mixture have been mixed in. Try make sure that you mix the silicone gently. If you mix too roughly and introduce too much air into the silicone it can create bubbles on the surface of your mold which can disrupt your casting. Once your silicone is completely mixed together and you're happy with how it looks you can now start pouring it into your mold. When pouring silicone into your mold try do it slowly and carefully adding a thin layer over the prop first. This thin layer will ensure that there's no bubbles or air trapped inside the mold against the sword so that you get a perfectly smooth cast at the end. Once you feel like that thin layer has released all the air bubbles and that it's nice and smooth over your prop you can go over and pour on the rest of your silicone. If you didn't mix enough silicone to cover the entire prop don't worry silicone sticks to itself so you can just mix a new batch and pour it over and it'll be one solid piece by the end. Once you finish pouring in the silicone for your mold you'll have to wait till it's fully cured to pull it out. For this we'll have to wait 24 hours before we can go on to the next step. Once the silicone has completely cured you can then pull off the foam walls flip it over and start to carefully remove the clay. Make sure you get off all the tiny bits of clay so that they don't interfere with the next part of the mold. You can also then take a craft knife and cut off any excess silicone that may have gone down the side of the walls and created a lip around the edge of your mold. Once the first half of your mold is completely done it should look something like this. Now we need to do the second half of the mold. Thankfully it's a little bit easier than the first half. We're just going to take some foam and once again start to glue it all the way around the silicone mold and create a wall to contain the silicone that we're going to pour in now. If there are any gaps around the wall between the silicone and the foam wall you can just take some more plasticine clay and push them into there to make sure that the gap is sealed. Now this step is really really important to make sure that your mold doesn't get stuck together. You're going to spray on the mold release again. I'm just using the ease release spray can and you're going to put it on liberally to make sure that the silicone doesn't stick to itself. As I mentioned before silicone likes to stick to itself so if you haven't put on any mold release your mold will bond forever so you're not going to get it open. So making sure that you spray the ease release on so it doesn't get stuck is really important. Now we're going to mix the silicone for the other half of the mold. So once again I'm measuring out my white portion of the silicone and then I'm going to weigh and measure the green portion of my silicone which is two percent of the white portion. I'm going to pour them together and then slowly and carefully mix them, scraping all along the sides of the tub to make sure that all the white and the green have combined into one smooth creamy mixture that we can then pour over our mold. Once again we're also going to have to wait until the silicone is completely cured so we had to wait 24 hours before we could pop our mold open. Once the silicone was completely cured I could then remove the foam wall and slowly and carefully pry the mold open. Don't pull too hard because you may rip the silicone if it is stuck a little bit because there wasn't ease release there. You can now remove any excess clay that you may have used to fill the gaps around the sides of the wall and you can remove the prop itself. And now you have a two-part mold which you can use to create lots of cool props and replicas. To create your casts all you'll need to do is put the two halves together, secure them with a nice strong board on either side and some rope and then pour in your resin. Stay tuned for part two of this video where we'll explain the whole process of casting a sword using your two-part mold. Thank you guys so much for watching, stay tuned for part two where we'll show you how to cast the sword using lightweight resins that are perfect for making cosplay props.