Molding and Casting

This section shows you how to make accessories by creating molds from existing Jem accessories in order to make your own in new and exciting colors.

This is fantastic for getting extra items that are so hard to get, make them in new colors that were never released. There are many things you can make using molds: Shoes, necklaces, bracelets, microphones, earrings and so much more.

The info shown here will also be helpful for making other toys and items too and explaining the molding process.

What is a Cast?

The Cast is the final item that you create by pouring two liquid plastics that are mixed together, called ‘resin, into the mold. Once the resin is set, then you have your completed item.

What silicones to use for the molds?

With silicones, which is the material for making the mold, I prefer to use a flexible silicone that can be mixed 1:1. This means when you mix part A with part B of the silicone, you have a good chance of getting the mix correct and a successful result. Where if you get a silicone which is 1:50 (Which is what I started with) so often the mix is not accurate which means either the mold will not set and stay a runny mess or it sets too fast and as you are pouring the mixed silicone, you end up with it setting as you are pouring which results in a non accurate mold and you gotta start again. So try and get a 1:1 silicone if possible or next best choice a 1:3.

What Resins to use for the casts:

With resin also try and get a 1:1 mix also or close to it for easy measuring. There are two main types of resin: Polyurethane and Epoxy. Each type are of two different chemical makeups. From my experience, I much prefer Polyurethane. Also, by sticking to that one type, it means I can mix any brands together if need be such as if I want to mix a rigid type and flexible type together for a material with a slight give. So there are different types of hardnesses available too. If you use a rigid type, make sure it has some sort of give and won’t break if some pressure is put onto it.

If you are looking for info on making molds and casting your own toy items, you have come to the right place!!! I have lots of info and even a tutorial to get started. Plus all the little info that the stores where you buy your supplies from don’t mention to you.

What is a mold?

The ‘mold’ is the item that is basically an inverted version of the final item you require. To make a mold, you need an item to start with, which you encase by building a wall round it and pouring silicone over to create a mold.

Firstly, I have some important info about molding, which is good to know what you are in for before starting.

Molding is a very tricky art and takes a lot of patience, creativity and money. So if you are up for the task and prepared for a some muck ups before you get the art of it, then you should definitely give it a go. With the Jem shoes, I do not know of anyone else who has pulled off a successful shoe from making molds, which shows just how tricky it can be to create. From my own experience of making molds, it has taken me 4 different mold designs of a Jem shoe till I found one that is really good. So getting my tips, will help you cut out some time consuming experiments in order to make your own Jem shoes and other toy items. When you accomplish making Jem shoes in new colors, transparent colors and glitters, you will see a dream come true before your very eyes! For me owning a pair of glitter Jem shoes was something I wanted for so long, so to be able to make them is just awesome!

Molding involves using chemicals. So it is something to be taken with care and precaution. Always wear protective glasses and use gloves when making molds. Something I have found though is, with getting advice on color additives and other things you can add to your molding materials, it is worth experimenting, as there is so much more that you can add for coloring that goes way beyond what the stores will tell you that you can only use. Same goes for mixing different brands of resins, which are the liquid plastics. Some will mix and some won’t, but it is worth experimenting.

To get your supplies, you can find molding supply stores sometimes locally and on the internet. Doing a google search will help you find the suitable store in your area or close by for posting, and for those like myself in Australia, don’t forget to type in ‘Moulding’ with the ‘u’ in the word into your google searches.

The products I use actually come from a range of different stores, as I am into experimenting with different materials. Something I have found really good about this is that some products are not what they are advertised to be and sometimes there is something better out there to be found, so I have found purchasing different products really valuable in what I have learnt as well as finding really ideal products suited to my needs. Also, some materials do differ depending on the batch, which makes things tricky also, so it is something to be patient with.

Getting advice from the stores is really helpful too. If you can go to a store in person and ask multiple questions, show them what you plan to make, see some product examples, they can be really helpful. Even calling up over the phone various times and getting info from different people will help you a lot. (Plus some people will tell you different things.) Also, some stores are kind enough to post out cured samples of their products to you.

How do the products work:

With both silicone for the molds and resin for the casts, they come in two bottles of liquid, part A and part B. The two liquids are mixed together, which forms a chemical reaction to form into a solid object.

Deciding on the setting time of the resin to buy:

There are different setting times available for resin. There are ones that set fast and ones that  take hours or days to set. For me, I like both fast setting resins, the type you can de-mold in 30 mins and one that you can de-mold in a few hours or to leave over night. For the really slow ones, they are just too long to wait on the results.

There are advantages to having both types. The fast setting one is what I recommend to start out with. This means you can see your results quickly, see where you have made mistakes and get on with completing the item you are making. Also, if you are adding glitter to the resin, using a fast setting one, means the glitter is not going to drop to the bottom of the mold and not give a consistent result. Yet the fast setting resin, adds tiny chemical reaction bubbles to the cast, that sit below the surface, so in a translucent color, they do show up, yet glitter still looks great, cos they work well with the glitter and solid opaque colors are also fine used with this resin, as you do not see the tiny bubbles as they sit under the surface.

So if you want a sheer, almost bubble free result for translucent colors, this is where the slow setting material comes in. If you are after the most bubble free result, the slow setting resin is best. As the slower setting time avoids the bubble chemical reaction. Still, one down side is that cos there is much more time for any air bubbles to rise, sometimes you end up with one obvious air bubble, or you could call it, air gap at the top of the mold. Also, some resins such as rubbery type flexible resins only come in the slower setting material, so sometimes this is the only choice. But for the really slow ones such as 24 hour setting time, their results are similar to one that is stated as 90 mins, so if you have a choice, go with the 90 min one as waiting a long time is just frustrating and so disappointing waiting that long especially if you get a nasty air bubble and have to wait another day for your results.

For me, I use both a fast setting resin that sets in 30 mins and a slower one that says it takes 90 (but needs a few hours at least in reality) so it does depend on the result I require, yet the fast setting material is the one I use the most. Yet keep in mind, I find most of the resins I have purchased that state the time they take to set, is always much longer than stated. Only one brand I use is accurate. There is a working time on each resin, which means how long you have till it starts turning into a gel and then the de-molding time, which means when you can take the cast out of the mold.

What color resin is best to get:

I strongly recommend only buying clear resin, then you can get any result you wish for. Some stores recommend using white resin for opaque colors and adding them to it, but from my experience, using clear is so much better. The white resin is good too and this is what I started with, but the white starts out clear and once mixed, sets to white, so after the color is added and sets, often the results turn out lighter than intended and often you get a pastel look for lighter colors and dark colors are hard to achieve. So by using clear resin for all colors, that way, as you mix the color into the resin, you can see that the color you are mixing is the result you will get. Of course, if you needed items as prototypes and only needed white, then the white would be good for something like this and that would mean no need to add color also, but if you want to have a resin that caters for all colors, go with clear.

How do I add color to my resin:

Molding supply stores often stock pigments and dyes to add to resin, yet I have found some of them to have a very limited range and certainly not always the bedazzling colors I want. So when you find a supplier with a wide range, go with them for colors. Most stores stock translucent colors, which means see through and then solid opaque colors. You can also add both together, such as if you have a translucent pink and an opaque white, you can then get a light opaque pink. These dyes are generally in liquid form. Some stores also stock metallic powders and one of my favorites, glow in the dark powder! So these can also be mixed into the resin, plus you can also use this stuff to add to sealer and use as a paint to brush over the top which is really effective for metallic colors like silver and gold. Basically anything that is in powder form, can be added as color for resin.

Yet, there are also other things that can be added to resin for color also. Here are some things I use also:

1. -Nail Polish
   

2. -Eye shadow or any other powder based color
   

3. -Powder Fabric dye
   

4. -Enamel paint
   

5. -Glitter!!!!!
   

Nail polish works great in resin. Added to the fast setting resin, it takes a touch longer to set, but helps reduce the chemical reaction air bubbles and is a great way to use up those nail polishes with some left in the bottom of a bottle. Plus it gives you a little more pouring time if needed.

Eye shadow makes for fantastic shimmery colors! Plus not a lot of stores stock this type of color. Plus for the girls, this is great for those times you have bought an eyeshadow just for one or two colors and have a bunch of others you don’t intend to wear, but now your toy making has a new found use for them.

Powder fabric dye can be really effective and interesting with granule dyes to give tiny dotted effects. Plus the powdery ones work well as an opaque color and can be a great way to get started with molding without having to buy dyes to start off with. The downside with these is that fabric dye tends to float and end up on clothing where you don’t particularly want it, so wear old clothes when using it.

Enamel paint works really well and especially the glossy paints, they give a very pretty glossy result. When used with the fast setting resin, they tend to add a white element to the result, well from my experience this happens with the product I use and it’s like what the white resin does, yet used with the slower setting resins or the ones that are supposed to be fast, but take much longer than stated, these can be fantastic! Plus they are also cheeper to buy and easier to find a decent range of colors.

And Glitter! Glitter is awesome to add to resin. You can add glitter on it’s own or even add some translucent dye with it and gives such a nice result.

So now you have all the info to get started and now practice is what makes perfect. One of the most frustrating things with molding is air bubbles. When making a silicone mold, it is so easy for air bubbles to get stuck and spoil your mold and have to start again, but do expect this. This happens to me often, but the good thing with silicone is, you can add to it. so depending where the air bubble is, sometimes it can be fixed by a re-pour over the bubble. There are different types of molds too. I am going to describe three main ones I use:

one part mold : This is where there is only one silicone pour resulting in one piece silicone mold. This is usually used for an item with a flat side.

Two part mold: This is where an item is trickier to mold due to it’s detailed shape. Half of the object is blocked off by modeling clay and the first silicone is poured. Once set, the modeling clay is removed, the first silicone is separated by vaseline, then the second silicone pour is made. Once set, you have a two part mold.

Seam Mold: This mold is made with two silicone pours, but they are bonded to fully enclose the item being cast, then the item is cut out of the silicone which creates a seam in the mold. I prefer this method when it can be used, depending on the item, over the two part mold, as it gives less of a seam line and is so much easier to make the mold for and to cast. This is a method I came up with, yet I am sure others have figured out this method also.

Now for a few tips. When mixing color to resin, mix it to part A or B only of the resin to get your color right and then mix both part A and B of the resins together. This gives you enough time to get your color correct and also the resins being mixed forms a chemical reaction and some colors go lighter once the two liquids are mixed and then goes back to the original color.

If you have read other molding and casting info, often the use of vaseline is recommended to use on the original item as a barrier when pouring silicone over it for the mold. This is the case for some items, but the vaseline adds elements to the mold, so with the items I use to mold from, I don’t use vaseline as a barrier, as I want my end result to be as exact as possible. Also, not using it, has not caused the item to stick to the silicone and still pops out of it very easily.

Do not expect every mold and cast to turn out first go as air bubbles do get trapped inside. But there is a trick with pushing on the molds to help drive out air bubbles and this comes with practice, still air bubbles still tend to sneak in there all the same, but it time, you will get less of them and more casts turning out.

I have got my first mold tutorial up for those who are ready to give molding a go. This is one of the easiest mold styles to make, which is a one part mold. So have fun with it, wear those protective glasses and experiment with color!!!