Rijacki Design

Alchemist’s Workshop Basics: Getting a Bit Moldy

Ms_Rijacki1Exploring the types of molds which can be used with resin and clay and showing some basics of how to use epoxy resin and epoxy clay with molds.

When ever I work with epoxy resin, epoxy clay, or polymer clay, I feel a bit like a mad scientist in my alchemist’s workshop combining and mixing up chemicals, ’cause I am. Muhahahaha, and I shall take over the world! err umm…

Alchemist’s Workshop is an on-going series of posts on working with resin, clay, and various other mixed media.

One of the ways you can use various types of clays and resins is to cast them into molds. Molds can give you the ability to make several items identical, add an interesting texture, or translate a shape into a new medium.

20150110_121728Just about anything the resin or clay won’t stick to can be a mold (and even some things it will stick to with the addition of a mold release). Some, though, are easier to use as molds than others or at least easier to get out of the mold once the resin or clay has cured *grin* Commercially produced molds intended for clay and/or resin are generally plastics of different types, silicone, wood, metal, glass, ceramic, etc. Of these, without extra care and preparation the metal is unsuitable for resin. Wood isn’t a suitable for resin no matter the preparation.

Warning! If you use a mold for any resin or any clay, you cannot use it for an edible substance later! 

I do a lot of my resin work casting in molds because I like the 3-dimensional effects I can get which aren’t as possible using bezels only. I’ve amassed a bit of a collection of molds of all different varieties and have become a bit of a mold junkie. I’m always looking for new molds to pique my interest even when there are some molds in my collection yet unused!

Transparent/Clear and Opaque Molds

ClearOpaqueYou can get molds of each type which are opaque and  clear or transparent. The handiness of the clear mold is that you can see what’s in the mold from more than just from where you’re pouring your resin or smushing in your clay. The opaque mold is a mystery until you remove the piece from the mold (for resin that’s 12-24 hours of pure mystery). Otherwise they work the same. On the left, a clear mold, partially cured, flipped. The right are opaque molds with the mystery spot black resin with silver.

 

Shiny or Matte

20150118_105614Using a mold, the pieces will come out shiny or matte depending on how the mold was made. If the mold was formed using a smooth shiny object, the resulting molded piece will be shiny. If the mold was formed using a matte finished object, the molded piece will be matte or have a frosted appearance. So how can you tell which your piece will be before you mold it? Sometimes there will be information in the sales listing if the mold is matte, but sadly not always. Once the mold is in your hands, look at the depressions in a light. Are they reflective or dull? If they’re reflective, the resulting piece will be shiny. If they don’t reflect light, the piece will be matte. In the sample, the one on the right is matte from a ice cube tray. The one on the left is from a plastic resin mold.

With various finishing techniques, it is possible to make a matte piece shiny or vice-versa. A later post on finishing techniques will cover adding matte and shiny finishes.

Releasing Agents

Releasing agents are substances that makes it easier to remove or release an item from a mold. Releasing agents come in various forms, liquid spray, powder, lotion, etc. The releasing agent is added to the mold before the resin or clay. Some you need to let dry before adding the substance to be molded. Releasing agents can make it possible to use some other wise unsuitable mold material types into a mold. Because mold release makes it easier to remove a finished item from a mold, you might not have to manipulate the mold as much, risking bending it out of shape.

There are several brands of releasing agents, also called mold release, for resin (see below). The only one I’ve currently used is Castin’Craft Mold Release & Conditioner which is widely available. Spray it in the mold, let the mold dry (I turn mine upside down for drying so nothing falls into in the mold like dust or hair), then pour in resin and cure as normal.

Just as with resin, read the instructions that come with a mold release package every time you get a new package for information on how to use it as well as what substances it will work with. Some mold releases are designed to be food safe for use with fondants and other edible substances that can be shaped. These may also work with resin as well.

For epoxy clay (and some of the other clays), you can often use corn starch as a releasing agent without it affecting your project. Dust in a light layer of corn starch and then press the clay into the mold. Some powdered pigments will also work well in this way with the double duty of adding a colour effect. With clay, you can often remove the molded item before it’s cured without distorting it or ruining the molded shape. Other substances that can be used as releases for other types of clay materials, such as metal clay and glass clay, are olive oil and clay conditioners. These may also work with epoxy clay and polymer clay though they might introduce unwanted effects with resin. If you’re using olive oil or corn starch as your releasing agent don’t use the same container you use in the kitchen. Pour off some into a smaller bottle to take to where you’ll be working with the clay. Never risk cross contamination with food (both for the food safety aspect and to avoid unwanted particles in your projects).

Resin Obsession has several resin appropriate mold releases, most other places only carry the Craftin’Craft Mold Release. After I’ve had the time (and money) to try out the other releasing agents, I’ll do a tutorial/review post specific to releasing from molds (perfect title for it just popped in my head: Please Release Me).

20150113_211809A non-releasing agent method to help get your cured resin piece out of the mold is putting the mold with fully cured resin pieces in the freezer for a short time (10+ minutes). When you take it out of the freezer the change in temperature will expand and contract the substances (the resin and the mold) differently breaking the seal between them. When I put molds in the freezer for this, I usually have them upside down so no stay food bits will get in them. When I take them out, I use the warmth in my hands to speed the temperature change process.

For some really stubborn molds, you can use both mold release and the freezer release.

Mold types

Commercially Produced Molds Marketed for Resin

There are commercially produced molds not made specifically for resin which I’ll cover further down in the “Found” molds section. The molds in this section are specifically marketed as “resin molds”. Most can be used for clays as well.

You can get resin molds from a variety of places: Beadaholique, Fusion Beads, Resin Obsession, Etsy, Amazon, and others. The best selection of resin molds I have found is at Resin Obsession. Their prices are pretty good, too.

Plastic

The plastic for resin molds is flexible which helps for removing the cured items from the mold. Plastic resin molds are relatively inexpensive, moreso when you find sales. The molds do not have find detail but are commonly geometric shapes or other shapes that don’t need crisp edges. These plastic type molds are generally clear. Mold release can help make demolding easier with these molds or you can use the freezer method.

You can get plastic resin molds from a variety of places: Beadaholique, Fusion Beads, Resin Obsession, Etsy, Amazon, and others.

Below is a sampling from my plastic mold collection. I’ve written sizes on some of them so I have a quick reference what the dimensions of the finished piece will be. The writing, in Sharpie, is on the spaces between the depressions. Most of these types of molds will result in shiny pieces. One of the plastic molds I own is matte, an Easy Cast Jewelry Mold.

plasticResin

 Silicone

Silicone molds can capture a much finer detail than plastic ones while still making it possible to remove the item from the mold. Silicone molds can also have a much thinner area for the resin (such as rings, beads, bracelets, etc) without risking the resin piece getting locked in the mold. Silicone molds a frequently opaque though some are available as clear. Silicone molds are rather pricey. Clear silicone molds doubly so. However, if you’re getting molds for rings, beads, bracelets, ear plugs, spheres, etc. having a clear mold is very helpful because you’d be able to see where inclusions of colourants are in the piece to be able to adjust them. I have only a small number of silicone resin molds because of their cost. I want more and, after using the opaque ones to try making beads and rings, I can see the major value of the clear silicone.

20150111_125629Silicone molds can withstand heat so will work well with polymer clay without removing it before baking. If your specific mold says it will withstand the heat levels needed to sinter metal clay, you may also be able to use it with metal clay.

You can get silicone resin molds from a variety of places: Resin Obsession, Club Bead Plus, Etsy, Amazon, and others. The best selections I have found have been from Resin Obsession and Etsy sellers, Resilin and Zougeebean, but others carry them as well. Sales can help with the costliness.

This sampling is from my mold collection (due to their high cost, this is all of the silicone resin molds I currently own).

Molds Marketed for Clays

These are molds marketed for clays or a variety of substances and not specifically for resin. Resin items made from these molds generally come out matte.

Silicone & Rubber

Silicone molds can withstand heat so will work well with polymer clay without removing it before baking. If your specific mold says it will withstand the heat levels needed to sinter and aneal your metal clay, you may also be able to use it without releasing it from the mold first.

Cool Tools has a line of silicone molds which have been made from antique buttons. They market them as being for clays but I find they work well with resin, too. Most are shallow or even rather flat so using them with resin can sometimes be tricky. The molds are a stiff blue (or blue for now) silicone which doesn’t have a lot of flexibility for twisting.

  • With resin, you have to very carefully pour to the shallow lip but not over pour (or not over pour too badly) and cure on a very level surface for best results.
  • With clay, if you’re using a releasing agent, you can usually remove the mold from the uncured clay leaving behind the amazing texture which you can then embellish.
  • With resin or clay, you can dust in a powdered colourant before the substance your molding to add effect.
  • When molding several at a time, a wax paper lined tray can be helpful.
  • If you’re using resin and you have over pours, when the resin is soft cured, you can usually pinch the excess off without affecting the mold or molded item.
  • For resin, these usually require a full or nearly full (24 hours) cure before removing from the mold.

This is not even close to a quarter of my antique button mold collection but does show a few curing after a resin pour (with a lot of over pour from my unlevel curing area) along with how they look fresh out of the mold (no additional touch ups). Most of these, in the pictures below, were silver (aluminum powder) brushed in the mold before black resin was added.

AntiqueButton

20150113_213716

Texture Tiles and Stamping Mats are rubbery flat patterned surfaces intended to be used to add texture to clay that’s been smushed on it. The samples in the picture are some of my Texture Tile collection from Cool Tools. Stamping or Molding Mats are available from a wider number of vendors (Shipwreck Beads, Firemountain Gems, and others).

There are several sellers of silicone molds on Etsy. These molds are marketed as being for fondant (type of edible cake frosting), chocolate, soap, polymer clay, epoxy clay, resin, etc. and are often hand cast or molded (a molded mold so you can mold the mold *smirk*) from a variety of objects and sources. From the ubiquitousness of some molds, one could surmise they’re using a similar source as the molding for the mold. Others, that are special to a particular shop, look to be made from something the seller hand crafted. The types of molds come in a wide variety of shapes and sizes some of which might not fit real well with jewelry but would work well in scrap booking.

My ctoothpickCompositeurrent collection of these types of mold is small but growing. Like the antique buttons, I will often brush them with colour first before adding resin.

For many of the sellers, they’ll have an option for food grade or not. The difference is in how they do the cure on the mold. For resin and clay, you don’t need food grade, but food grade won’t make a difference to your molding. If you’re using your mold for resin or clay of any kind, you cannot also use the mold for edible products as well. If you get two of the same mold so you can have one for edibles and one for resin and clay, mark them well and never ever ever mix them.

Warning! If you use a mold for any resin or any clay, you cannot use it for an edible substance later! 

  • Other Silicone and Rubbery Molds and Tiles

There are other commercial manufactures of molds for metal and polymer clays that can also be used with epoxy clay and resin (most have shallow impressions, so pour carefully).

  • MarthaStewartMartha Stewart had a line of silicone molds which has since been discontinued. These might still be found from various vendors like Fire Mountain Gems that sell retail products intended for craft stores.
  • Lisa Palveka molds can sometimes be found at Micheals (or also at Fire Mountain Gems and other places).
  • Mod Podge has a line of molds they market as being for hot glue or their own line of an epoxy clay type foamy stuff. These work well for resin or other clays, too. I have found these at Michaels and other craft stores.

I’ve gotten a few of these when I have found them on deep discount sales. Like the other silicone molds with details, I often use powdered colourant dusted on the mold before pouring.

 Metal and Wood

Metal and Wood Molds cannot be used with resin. Even with mold release, it could be unlikely you’d be able to remove the cured resin from a metal mold. Wood molds would likely absorb the liquid of the resin, destroying the mold. Metal and wood molds can work with clays if the clay can be removed before curing. At this time, I don’t have any metal or wood molds to show as samples.

Clay Extruders, well, extrude the clay through small holes of various shapes at the front of the tool by pressing on a plunger at the back of the clay filled tube, rather like a the plunger for a hypodermic needle. I haven’t tried an extruder with Epoxy clay since uncured epoxy clay is a lot less stiff than other clays. I’d also hate to deal with the clean up. When I do a post (or series of posts) on polymer clay, I’ll cover the use of an extruder (and include pictures *grin*).

“Found” Molds

There are several items not specifically marketed as “molds” or not specifically for resins or clays that will work wonderfully with resins and clays and others which won’t work for resin will work for clays.

Warning! If you use a mold for any resin or any clay, you cannot use it for an edible substance later! 

(Do you get the feeling I really want to stress that warning? *grin*)

You can test a potential mold for its use with resin (or clay) by putting a small amount of resin (or clay) on the BACK and letting it cure away from the area where you work with resin and clay. Once it’s cured, if you’re able to remove the cured substance easily, then the mold should work well with it. By testing the substance on the BACK, if it’s not suitable, you won’t have destroyed its ability to be used with its intended edible substance. 

20150116_111957Ice Cube Trays

Ice cube trays made of flexible silicone are great for resin. Ice cure trays of rigid plastic are not. You can find some silicone ice trays in ‘fancy’ shapes often for rather cheap ($3 or less each) at kitchen stores, some Dollar stores (not up here for some odd reason), or even just online from Amazon. The advantage with an ice tray is you can cast several identical shapes at the same time. Ice trays are often rather deep. You generally don’t need to fill the full depth, just a 1/4″ or so will do. All of the ice cube trays I have give the cured resin a matte appearance.

 Cookie Cutters with Silly Putty

20140425_073616When used with Silly Putty on a Texture Tile, Stamping/Molding Mat, or wax paper, a cookie cutter can allow you to make a different shape mold to use with resin.

  1. Put a cookie cutter in the place where you want to capture the texture.
  2. Build a Silly Putty wall around the cutter smushing the putty down into the crevices to prevent leaks.
  3. Carefully take the cutter out.
  4. If desired, add in colourant to highlight the texture.
  5. Pour in the resin.
  6. Cure on a level surface.

Silly Putty can be used on its own for a temporary mold but you would want to put it in a container to help the putty hold shape for the full curing time. Since Silly Putty is so cheap, I haven’t tried the dollar store version.

Plastic Candy, Candle, and Soap Molds

20150118_110500These types of molds are often a rigid plastic. What makes them only partially suitable, especially for resin, is their rigidity. This makes it extremely difficult to remove a cured piece. You may be able use one of these molds with the aid of Mold Release or even with the freezer method, but even then be prepared for a lot of swearing and cursing as you attempt to release your project from the mold. It’s also very easy to accidentally crease the plastic in the depression as you work to release the resin. I got my sample mold for super cheap on a clearance sale just to experiment.

Pastry Molds and Cake Pans

Silicone cake pans can be used with resin, just be sure not to make your pour too deep or it might be unwieldy when finished; 1/4″ to 1/2″ should be enough for rigidity when cured. Metal cake pans may work with clay, especially the small ones intended as tarts. Metal would be unsuitable for resin without some sort of mold release and even then it would be dicey. Since cake pans are often large, items made with them are unlikely to be for jewelry but would make great house decoration.

I don’t have any examples currently, but I do have my eye on a few on Amazon. You can probably also find these in some Kitchen stores.

Rubber Stamps

20150113_213802Usable more with clay than with resin, rubber stamps can add texture or a design to the clay.

To make it easier to get the clay off the stamp, you can use a releasing agent or powdered colourant. To give a stamping in clay a more stricken rather than stamped look, after you stamp the uncured clay you can use a flat surface to smush down over the stamped area.

You can also use rubber stamps to make impressions on paper or cloth and use that as an inclusion in resin (after sealing it first, of course.

Paint Palette

paletteOne of my most favourite resin molds is a super cheap plastic paint palette I use all the time. It makes a really nice super shiny smooth large (33mm) dome/bauble. Because the palette is mostly rigid, I use the freezer method to convince the pieces to come out. The cured resin slides right out once the seal breaks.

I first heard of using paint palettes from a Youtube video on making fursuit eyes but I use it more for marbling effects.

 

Self-Created Molds

21051You can create your own molds from a few other substances.

Silicone: You can easily find silicone mold making materials in liquid and putty forms. For either, you would want to follow the directions on the box to mix the silicone and form it around the object you want to copy.

Clay: Polymer clay and other clays can be used to shape an original to cast with silicone or on its own.

I have yet to make any of my own molds, but it’s high on my list of things I want to do (I need more hours in the day to do everything I want). Once I feel confident in my skill at that, I’ll make a post on it.

Suggested Safeguards while working with epoxy resins or epoxy clays:

  1. Avoid getting resin or clay on your skin. Wear non-porous gloves such as nitrile, vinyl, or latex.
  2. Avoid getting resin or clay in your eyes. Wear goggles especially when sanding any resin pieces and even while pouring.
  3. Avoid breathing the epoxy fumes. Work with epoxy resin or epoxy clay in areas of good ventilation and/or use a fan to keep the air moving. For other resins, such as polyester, you may need a respirator and to work outdoors exclusively.
  4. Avoid breathing resin or clay particles. When sanding, wear at least a paper mask.
  5. Avoid getting resin or clay on your clothes. Wear an apron. Resin on cloth cannot be cleaned off. It will permanently bond to the fibers even without curing.
  6. Read the instructions for the resin or clay brand every time you open a new package.
  7. Read the MSDS (Material Safety Data Sheet) for the resin or clay brand.

Using Molds with Resin

Pouring resin into the mold

  1. Prep your molds before you mix your resin.
  2. Mix your resin according to the directions with the bottles. You can also read my Mixology post for information on mixing 2-part epoxy resin.
  3. Place your molds on a level surface.
  4. If you’re putting resin into a deep or wide mold, you can slowly pour from the cup.
  5. If you’re putting resin into a shallow or small mold, slowly drizzle the resin from the stir stick or a toothpick to control the amount of resin more easily.
  6. Pour or drizzle less resin in the mold than you think you’ll need.
  7. Add the resin slowly, both to control the resin amount and avoid bubbles.

PourCompilation

You can add a second pouring of resin after the first without the 2 layers mixing, if you allow the pieces to get to at least a partial cure.

I’ll go more in-depth on additional pouring techniques in a future post.

Removing the cured item

When you’re demolding or removing a cured item from the mold, you need to break the seal between the resin and the mold. With a flexible mold you can often twist the mold somewhat (careful you don’t bend the mold out of shape so it can’t be re-used). When the seal breaks, the resin/mold will generally make a cracking noise, don’t be alarmed. If it’s a clear mold you, when you see a colour change on the molded surface when you’ve broken the seal (partly or entirely) and are getting air between the cured item and the mold. Occasionally it helps to bang the mold on a hard surface to break the seal (just like you do with a jar lid). Once the seal is broken, just slide or pop the cured piece out.

demold

If you’re popping a small item out of a mold, careful you don’t invert the depression and ruin the mold for future use.

If you have an extremely flexible silicone mold, you can sometimes peel the mold off the cured item.

TIP: If you have a mold with multiple pieces, you should remove them all at the same time. If some require a second pour, don’t remove the ones which don’t . If the seal is broken when you go to put in a second layer, the resin will seep around the sides to the front. Unless that’s the look you want, keep the seal until all resin is cured in the mold.

Finishing

When you take resin items out of the molds, they are rarely every exactly perfect and in need of no additional work. If you don’t fill the mold depression to the top, the item will often have a concave back with sharpish edges. If you poured resin into a shallow mold, it may have gone over the edges.

  • cuttingCutting

If the resin is soft cured or has thin edges, you can often use a sharp pair of scissors or a sharp craft knife to carefully cut them away. Wear protective covering for your eyes while cutting the resin especially if it’s in small snips, like the picture, between molded elements of the piece.

  • Sanding

When sanding a resin piece ALWAYS wear eye protection and a particle mask. You do not want any of the grit in your eyes and you definitely do not want to breath in any of the resin particles. You can find cheap plastic protective glasses and paper particle masks at any hardware store.

My favourite sanders for small resin pieces are nail shapers from the Loonie store, but sand paper in various fine grits works well, too.20150113_222007

  • When you’re sanding with a ‘stick’, sand in a single direction preferably from the front of the piece to the back. This will direct the removed bits to the back of the piece and avoid a ragged edge. Mold edges also come off easier this way (middle picture).
  • When you’re sanding on a flat surface, move the piece in figure eights or circles.

sand

TIP: If you have a large area or large pieces to sand, it’s best to use wet dry sand paper and do the sanding underwater to help reduce the particles from getting airborne and keep the resin from heating up from the friction and melting the particles into the piece.

  • 20140318_230214Additional Resin

After a piece is out of the mold, you can add additional resin to the back of your molded resin piece or the front of your molded clay piece in the same way you would pour resin in a bezel. The example shows added resin to an epoxy clay molded item.

  • Additional Colourant

Paint, patina, Gilder’s paste, etc. can all be added after you’ve removed the item from the mold. If you add colourant, you may want to seal the piece as well to make sure that colourant stays where you want it always.

A future post will cover a wider range of finishing techniques.

 

Using Molds with Epoxy Clay

  1. Measure out two pea shapes of the epoxy clay, one of each part. Since epoxy clay, like epoxy resin, has a limited pot time (a little longer than resin’s) it’s best to work in small batches.
  2. Flatten the two peas and squish them together. Wearing gloves while mixing the epoxy clay, especially one which is pre-coloured, is highly recommended. Gloves will protect your hands from the pigment as well as the chemicals.
  3. Knead the clay until all the marbling is gone. At this point the clay is ready to used.
  4. At this point, too, for the pre-coloured epoxy clay, the pigment is incorporated and less likely to come off on your hands. If you need to have more tactile control than the gloves allow, this is a good time to take them off. If you have a wet wipe handy, you can use one to wash the clay remnants and colourant off the gloves before you take them off, to make them re-usable.

eclay

There are two main ways you can use epoxy clay with a mold: molding it alone or putting it into a bezel and then molding it in the bezel. The first method would work with other types of clay as well.

No Bezel:

  1. eclay_mold1Roll the desired clay into a small ball or a small disk.
  2. Squish the clay into the mold.
  3. Carefully unmold or allow the item to cure in the mold before unmolding (using a releasing agent is recommended for curing in the mold).
  4. Just as with resin, once the clay item is cured, you can use sand paper on the edges or back (use a particle filter mask and protective eye wear).

Bezel:

  1. Squish the clay into a bezel.
  2. Sandwich the clay between the mold and the bezel.
  3. Squish the bezel into the mold.
  4. Carefully unmold.
  5. Clean up the edges of the bezel. You can use your fingers or a stir stick and then a wet wipe to remove residue from the edge.
  6. Carefully add other embellishments or colourant. You should leave the patterned area alone as much as possible.

eclay_mold2

Additional techniques with epoxy clay will be covered in a future post.

The same mold used for both epoxy resin and epoxy clay. I bought this mold on Esty from moldsrus: Celtic Design Mold Flexible Silicone.

resin_clay_mold

Clean up for Molds

20150113_224944Aside from any clean up you may need to do for your resin or clay, you will also want to clean up your molds, especially if you’ve been using powdered pigment, mica, or glitter directly on the molds.

  1. Peal away and remove any cured resin or clay.
  2. You can use an old toothbrush and a bit of soap and water to scrub your molds, especially those with patterns and small crevices. I like using brush cleanser but hand soap works fine, too.
  3. Leave the molds to dry completely before you use them again.

TIP: Don’t wait to clean your molds. Clean them shortly after you’ve removed the resin or clay. They’ll be easier to clean and will last longer.

Leave a Reply

Your email address will not be published. Required fields are marked *

Handmade Jewellery by Kate Ledum