Over the past few years, I've been making molds for miniatures. The molds I make are not very complex but they get the job done. I don't have any fancy equipment like a pressure pot, but I do have the confidence to work my way out of a problem.
The first miniature I ever casted was one of Trent from Miscast's Plague Toads. I manage to snag one off his shop and it made the long journey across the globe to my door step. This was the first time I ever use silicon and resin. The only video I watched on mold making was the one of Trent creating the mold for his Toad. Somehow I managed to make a mold and quickly after I started making molds for other figures. Most were successful and others were complete messes, but every time I made one I learned so it never felt like a waste of time or materials.
Recently I was commissioned to make a mold of one of Trent's Toads for a person to take to conventions to use for casting. I never sold a mold before but I knew I could make one of good quality. At this point, I have easily casted over 100 toads, sending them all over the US and even worldwide.
To get started, I rummaged in the cabinet and got the original Plague Toad free. I do have a bunch in there that people have casted from this toad or their own interpretations of the toads. It's been fun to see what everyone has created starting with the same miniature.
After the Toad was freed, it was time to glue is down to a base. I usually use a piece of scrap card board or piece of bristol board. To make sure the Toad is surcurely glued down, a blob of hot glue is used.
Next, its time to imprison the Toad in a chamber. I usually use a disposable cup since its just the right size. With an knife, I cut off the top of the cup to allow to silicon to be poured into the chamber.
Take the cup and center it over the miniature as most as possible. You do want there to be a decent amount of space as thick walls will increase the strengthen of the mold and helps reduce tearing.
To seal the cup to the base, a generous amount of hot glue is going to be used. Even when you think you used enough hot glue, use more. Gently apply pressure to the top of the cup to create a seal while beginning to hot glue the edge of the cup. Make sure to cover both the lip and part of the base paper. Use alot more glue then you think.
Follow this same process around the entire circumference of the cup making sure to take your time and leaving no gaps. Fill in any spots you missed to reduce the silicone leaking out later. Even when I think I'm done, I will generally add another layer of glue. A mold like this will use 3-4 small hot glue sticks. I rather spend the few extra cents on glue than the pain of cleaning up leaking silicone later. If you do not feel confident with just glue, surround the base with cheap polymer clay to add an extra layer to dam any leaking silicone.
Now it's time to break out the Silicone. I don't really have any recommendations of what to use. I would just use what ever you have access to at your local art store. I rather buy this in store to make sure it's not expired. Personally I just use silicone that is a 1:1 ratio because I don't want to do math. I also like to use a mold with a longer curing time, this allows for bubbles to escape since I don't have equipment. This is what I used for this mold. Its very flexible making demolding a breeze.
Make sure to wear gloves and work in a well ventilated space. Also read the directions to make sure you're following the specific products directions. Take a cup out for each part and fill to the correct amount. Don't worry you will either make not enough or too much. In this case I was making two molds and knew I would need a good amount of silicone.
Pour both part A and part B into a third cup at the same time. Do not pour one into the other, you want both parts to go to the bottom to the top of the liquid. Use a popsicle stick and mix the material until its one color. I usually mix for at least 3-4 minutes, but I have that time since the silicone does not start curing for about 20-30 minutes.
From a distance above the model, slowly start pouring the silicone in a thin line down to the model. This will help bubbles break on the way down.
Take your time (if the silicone cure time allows) to slowly fill the vessel. This will also allow you to see if there are any holes in the glue. If there is a hole, don't file it with glue. Use polymer clay and jam it into the spot that is leaking.
Don't stop once the miniature is covered. Add more silicone to help strengthen the mold. It doesn't have to be too much, but you shouldn't be able to see the miniature at all.
Once the mold is filled, leave it to cure! Don't poke it and move it around too much. Just leave it alone until the cure time passes. Once fully cured, pull the mold off the paper. If its stuck to the cup, use a blade to cut it off. Cut the cup off the mold and gently push from the top of the mold to see if the miniature will pop out. If it doesn't pop out, that means you will likely need to cut into the mold to create more space. The Toad is the perfect shape as it pops right out. But more complicated molds I've made have required cutting into the mold. The best way to do this is with a new, sharp blade and taking your time. Cut in a zig zag pattern to make fitting the mold back together much easier.
Now that you have your mold, you can start casting! You can cast with lots of different materials: resin, plaster, or wax. Personally I like to use Smooth on Liquid Plastic since it has a 10 minute cure time and it degasses itself.
If you want to try casting a Toad for yourself. I just restocked my store! Follow the link to adopt a Toad and spread them all over the wold.
No comments:
Post a Comment