Tuesday, August 3, 2010

Plastic Moulding

What is plastic moulding for resin?

Resin plastic moulding is the reusable plastic moulds used to create resin items such as resin jewelry, plaques, souvenirs and sun catchers, drawer handles, and custom tiles. Moulds used for food items MUST be clearly labeled as “food-safe” plastic moulds. It is incredibly easy to make unique resin jewelry and crafts from a variety of resins, transparent and opaque dyes, and artifacts like small charms or flowers to embed are endless.

What kinds of resin plastic moulding are available?

Plastic moulding is durable reusable moulds; they are available in self-releasing polypropylene and polyethylene plastic molding, used especially with clear polyester resin and casting epoxy.

TIP: Though effectively self-releasing, it is good standard practice to thoroughly condition and clean your molds with a mould release/conditioner before and after each use. Castin’Craft Mould Release/Conditioner is most often the release/conditioner of choice by knowledgeable resin aficionados.

How do I make a resin casting with plastic moulding?

Making your own resin jewelry or project is easy with a plastic mould and some resin, especially with one of our Beginner Resin Kits.

1: Protect your work area with freezer or waxed paper.

2: Spray the clean mould with mould release/conditioner.

3: Place the mould on a level surface, and fill the mould cavities to just below the top with resin.

4: Once cured, simply flip the plastic moulding tray over, and press the center of each piece to release it, flexing the mould if necessary.

There are a wide variety of ready-made plastic moulds available for you to use. ResinObsession, an online store started by Cindy, the enormously gifted ResinLady, stocks a large inventory of many different types of plastic moulding in a wide variety of subjects and shapes. She’ll also be happy to create a custom mould for you. Should you have any problems or questions concerning your resin project, don’t hesitate to contact Cindy—she loves to help and problem-solve with other resin crafters, whether you are a total beginner or someone who has been resin crafting for years.

RTV Silicone

rtv silicone

Though first developed in the late 1930’s Room Temperature Vulcanizing or RTV silicone was created to be an insulating material that could withstand the heat produced by smaller engines. Still used in the electronic industry for potting and encapsulation, it is now primarily used to make durable, flexible, and easy to use molds suitable for a wide range of casting materials.

The entertainment industry was transformed by the scenes and characters that now come to life on thanks to the development of RTV soft “skin” silicone rubbers. Platinum cure silicone is also used in the medical field for prosthetics and other specialized uses.

In addition to making strong, flexible custom resin molds that perfectly replicate the original artifact down to the most intricate details, the molds cast with it have good elongation and tear strength and excellent directional stability. RTV silicone is available in both condensation (tin catalyzed) and addition cure (platinum catalyzed) formulations, both of which are comprised of two-components which must be mixed for activation.

The two components of RTV silicone are usually referred to as Part A (silicone component), and Part B, (catalyst component). Both liquid, Part B, the catalyst, is usually of a different color— when the color is consistent and has no more streaks in it, it is fully mixed.

It is always a good idea to fully read the manufacturer’s instructions and complete as much of the mold-making construction and process as possible before mixing the two components since the open time is fairly short, anywhere from 30 minutes to 2 hours.

ResinObsession carries a full line of easy to use RTV silicone rubbers which do not require vacuum degassing with varying open and demolding times to suit the time requirements you may have in your custom mold-making projects, and Cindy, the ResinLady, to answer your questions.

Sea Glass Tutorial

How to make imitation sea glass with ResinObsession Super Clear Resin


• ResinObsession Super Clear Resin

• 738 Cabochon Mold

• Castin’ Craft Mold Release Spray

• Reusable measuring cup or a Plastic cup

• Stir Stix

• Disposable Spoon (optional)

• White glitter

• Castin’ Craft transparent green dye

• Rolling pin

• Non-stick mat (like one used for cooking)

1) Spray the mold with conditioner and leave to dry.

2) Measure your resin into a disposable cup according to the directions. I like to measure mine in level teaspoons, but you can use the provided measuring cups. Mix well and leave to stand for a couple of minutes.

3) Add a small amount of dye to the mix until it is the color you want. Add just a pinch of white glitter and mix well - this is the secret to the realism!

4) Pour the mixture into the mold until half-full and leave to partially set. I left mine inside of a hot box or under a light bulb to speed up the process, but you can let it set in a normal environment. This mold is best because it gives nice sized pieces to work with - when half-full it give a realistic sized pendant.

5) The resin is ready to be manipulated when the surface is no longer wet, but the mixture is still very soft when pushing on the underside of the mold. Keep an eye on the curing as different room temperatures and situations change the speed that it takes to get to this stage. Pull the resin out of the mold with a blunt object (you can use the StirStix so not to damage your mould), any extra bits left inside can be picked off once fully cured.


6) Tear the resin into pieces if you want smaller pieces, or for a decent sized pendant leave the blob whole. Shape roughly with your hands and put on a non-stick mat. Don’t worry about fingerprints, this will slightly frost the surface which is a good thing, and most will be lost once fully cured as it does smooth out a bit more after this stage.

7) Use a rolling pin to lightly squish the piece on the drying mat into a flatter shape so to mimic the thickness of old glass.

8) Leave to set in a cool environment for at least 4-5 hours. Then you are free to drill and do as you wish with your faux sea glass!