Tips For Working With Latex Rubber

Liquid latex rubber is a simple and easy to use compound. The properties are varied – ranging from economical to tough and durable. However, proper usage is essential to make the most of the rubber.

Latex rubber is a natural rubber with a base of water and ammonia. It is an inexpensive material that is available in a ready-to-use form - no measuring or mixing is required at all. What’s more, the same latex comes in two types – mold making rubber and casting rubber.

The latex rubber is easy to use and works to be the most economical of all mold making and casting materials. However, there are certain precautions that the artist should keep in mind to be able to use the rubber compound well. Such as –
•    Latex comes in a liquid form. The rubber can last for years as long as it is kept in an air-tight container and away from direct sunlight. Exposure to air or light will cause the latex to turn pink. Yet, this does not affect its workability.

•    In case the latex gets thick, it can be thinned easily by adding a bit of water or household ammonia itself.

•    Do not allow the rubber to freeze as this will render it unusable.

•    Making a latex mold takes time and patience. Do not pour the liquid latex over the model and expect it to set solid. The latex should be applied one coat at a time, with each coat being allowed to air dry properly before applying the next one. Else, the outer layers will set before the inner layers, causing pooling, soft spots or even rendering the mold unusable. 7 to 10 coats are usually required to build up the thickness of the mold.

•    A latex cast can be made only in a plaster mold. The process is simple – just pour the liquid latex into the mold, swirl it well and leave it for some time before pouring out the latex once again. A thin skin will be left behind in the mold that cures quickly. This procedure is commonly used to make a latex mask.

•    A latex mold or cast cannot be colored in the usual manner using regular paints and dyes as they will tend to crack. Special latex pigments in different shades are available in art stores. The required color can be added to the liquid latex or even painted on a cured latex surface. For the latter, the pigment should be diluted with liquid latex rubber itself. Some artists even mix clothing dyes in the liquid latex.

•    A cured latex mold or cast will last long – for 20 years or even more. Cured latex can be vulcanized or dipped in boiling water to prolong its life.

•    Latex rubber is easy to clean as well. Just allow the spilled rubber to set and it can be peeled off easily. Tools and brushes can be cleaned with warm water itself.

How to Craft Life Out of Molds?

The crafting industry has always focused on casting and mold making. Although their uses and applications are varied and longstanding, they play a pivotal role in today's artistic production as well as industrial manufacture. From leagues of centuries ago, sculptors and other artists have used plethora of techniques to make life-like casts. Today of course, the methodology has gone through a sea-change but the basics remained the same.

So before we get into the process of how to make molds, let’s understand what exactly this thing is. Mold is a distinctive block with a hollow cavity made out from a desired model (object). A mold is used to create the cast by pouring liquid wax (or other preferred molten material) into the hollow cavity. To remove the cast from the mold, a releasing agent is used which is nothing but a specific chemical that stops the both from sticking to each other.

Ceramics and glass items for tableware perhaps have been the oldest uses of molding and casting. Whether you want to make one or a hundred replicas of the original, you can do it with a mold.

The steps are generally pretty easy to follow even for the first time mold maker. Get the mix ratio correct (follow the instruction on the kit) although no weighing is necessary as such. Next, pour the material over the desired object and set it aside. If the model is some part of your body like the hand, keep it still. The set time is different for different materials. For instance, alginate sets faster in warn water than when mixed in cold water. After it is set completely, it is advices to reinforce the alginate with a plaster jacket of bandage. Once it’s cured, the entire thing is removed as one. This takes a bit of caution as alginate is very fragile. It can then be colored if required.

EnvironMolds is one of the reputable names in the casting and molding industry. You can order the kits for mold online from their website They also have the guided video instruction to follow in case you want to learn it on your own!

Painting on Casts Made Possible

Mold making and casting are advanced arts that involve the use of specialized materials like resins, latex rubber and silicone rubber. These materials are easy to use and produce excellent molds and casts.

However, painting them is another story altogether. Most artists are confounded when their painted casts start chipping or cracking very soon.

The fault lies not in the material or the technique, but in the paints themselves. Regular paints just do not work well will rubber or resin materials. And this is exactly why EnvironMolds has devoted a complete section to specialized paints and dyes like silicone paint, latex paint and resin paint.

On the website, you can easily locate this segment under the Art Supplies tab. It throws up various options of specially created painting and pigmenting systems for latex, silicone and polyurethane applications.

There are a range of pigments that should be mixed with the corresponding paint medium before painting on a cured surface. Or you can also mix the pigment directly in the casting material itself before adding the catalyst to get a uniform intrinsic color on the entire cast.

There is also an exceptional offering called I-Glo photo-luminescent pigments. This comes in a crystal form and can be mixed into a clear casting resin or sprinkled over a finished surface before sealing it. It will create a glowing effect in the dark by absorbing light during the day. The pigments are invisible during the day, thus creating two distinct looks for the artwork.

All the above pigments are so formulated that they bond with the rubber or resin material. As they become a part of the cast itself, they will not chip, crack or rub off at all.

So, remember to use the right resin, latex or silicone paint for finishing your cast!

Why You Need A Secondary Mold?

A mold that accurately reproduces the shape and details of a model can be used for rubber or resin casting, as needed. In fact, depending on the type of mold and the casting process used, a mold can be used over and over to make multiple casts of the same object.

casting resin types

However, every mold comes with a finite use life. It may end up deformed, tarnished or even cracked and broken after repetitive use. Would you then go back to making a mold of the object all over again? In case of a life cast, does it make sense to go to the trouble of making a body mold again and again? 

Anticipating such scenarios, experienced mold makers prefer to make a secondary mold before starting the casting itself. This copy can be used to continue with the casting even when the original one is spoiled or damaged. Moreover, it is possible to vary the material for making the secondary mold – like choosing polyurethanes or rubbers - thus extending the life of temporary alginate molds and the like.

Secondary molds bring another benefit into play. If the original mold has minor faults like bubbles, wrinkles or spots, the secondary mold opens up the possibility of correcting the flaws by improvising on the original piece. In fact, a mold maker can make one secondary mold after another till all the defects are corrected and the mold becomes perfect in every sense.

Therefore, mold makers are always advised to make a secondary mold just to be on the safe side at least.

You can source all your mold making and casting requirements easily online from

Vacuum Chamber: A Must For Deairing

I use a variety of resins for my casting works. Most of my resins have a propensity to trap air and I regularly place the mold with the resin in a pressure pot. This removes all the air from the material and makes it disappear. As I let the cast cure in the pot itself, I get a perfectly bubble-free casting.

However, when I moved to making rubber casts, the bubbles seemed to return once I removed the rubber from the pressure pot. After several failed attempts, I gave up and bought a vacuum pump with vacuum chamber from

Actually I had called up my regular supplier at EnvironMolds, LLC to discuss the issue first. He told me that a pressure pot does not work as effectively for soft casting materials like rubbers, especially silicones.

The suggested vacuum pump with vacuum chamber was reasonably priced and very easy to operate too. All I had to do was mix the rubber and pour it into a large container. The container should be big enough to accommodate four times the amount of rubber I wish to vacuum, as the rubber expands under a vacuum.

Simply switching on the machine initiates the vacuum process that removes all the air from the rubber. All it takes is a few minutes and the air is eliminated, never to return. I leave the container in the chamber for some time and later open the plate slowly to allow a gradual introduction of air.

As an added precaution, I place the mold box with the casting rubber in the vacuum chamber once again. The vacuum pump works its magic and the material easily flows into the tiniest grooves and undercuts of the mold. My casting turns out flawlessly without any sign of the slightest of bubble.

I seriously recommend that every mold maker or casting artist should own a vacuum chamber irrespective of whether they work with rubbers or not!

How To Use Silicone Rubber

Silicone rubber is a material of choice for making molds of figurines, giftware and robotic figures to even prototype tooling, prosthetic pieces and special effects. A wide variety of silicone rubbers are available in the market ranging from the regular silicone formulations to skin safe, food safe and skin-like translucent options.

Not only does silicone perfectly capture the surface details of a model, but the rubber is very simple to use too. Following is a look at what goes into making a simple silicone mold:

•    Silicone rubber is a two-component material with the base and catalyst usually mixed in the ratio of 10:1 by weight. You need to stir and shake them properly before weighing the appropriate amounts in separate containers. Place the base material in the mixing container and roll it around to coat the sides as well.

silicone RTV rubbers

•    Pour the catalyst into the container and mix them thoroughly making sure that any material is not left unblended on the sides or bottom. You should not use a mixer machine or even mix too vigorously as this will introduce air bubbles into the silicone rubber.

•    Despite the most careful mixing, some air is bound to get entrapped in the mix and will form unsightly bubbles on the mold. Degassing in a vacuum chamber will release the air and make the rubber bubble-free.

•    Once vacuumed, slowly pour the mixture in a thin stream from a corner of the mold box till a thick and even layer forms all over the model.

Quality Silicone Mold Rubbers

•    Keep in mind that though the work life of silicone varies from one brand to another, it is usually under an hour. Even the pot life is limited to a couple of hours at best.

•    As silicone rubber does not stick to anything but itself, it will get demolded easily. Yet, some mold makers prefer to coat a thin layer of release agent to allow the mold to slide off without any effort. Sealing the model and mold box is essential as the rubber may get absorbed into them.

•    The rubber mold requires 16 to 24 hours to air cure. Demold only when the mold feels rigid and is no longer tacky. Allow it to remain at least another day before proceeding to casting. Full cure may take almost a week.

•    The cured silicone rubber mold is usually blue in color. It will reproduce the exact detail, have a smooth finish and is ready for casting. You can cast polyurethane resin, epoxy resin, polyester resin, polyurethane rubber and many other materials in the silicone mold simply by pouring the material into the mold. Demolding the cast is also easy as silicone rubber will not stick to anything.

mold making silicone rubber

In sum, silicone rubbers are a great option for making molds of various objects.

Get Going With Mold Making

Mold making is something that may sound bland and boring to a beginner. But once you get down to actually doing it, making a negative image of a model with your own hands can be incredibly exciting.

You can choose anything to begin with – be it a small figurine you especially like, a spare handle or even something ordinary lying around in the house. Indeed, it is possible to make a mold of just about anything that catches your fancy, your own body included!

If you are wondering about how to make a mold, there are varying techniques and you can use diverse products as well. In fact, a simple material like clay is the best mold making material for a novice. All you have to do is shape the malleable clay to form a covering over the model. Once it dries, remove it gently and you can see the silhouette of the model captured on the underside, complete with all the curves, folds, nooks and indentations.

Apart from this, wax, plaster bandages, alginate, moulage, polyurethane resin, latex rubber, silicone rubber and many other materials can be used to make a mold. You will need other products and accessories too - like sealer, release agent, vacuum chamber, mixer, brush, spatula, etc. – depending on your choice of technique and materials. All these can be easily sourced from EnvironMolds.

Again, a mold is not always ready in one go. At times, you may need to make two part molds or even multi-part molds for more complex shaped models.

All this may sound pretty complicated, but slowly you will find yourself able to make keys, spues and more very easily. And the satisfaction of using your mold to create a spitting replica in the form of a cast is simply incomparable!

EnvironMolds, LLC
18 Bank Street, Suite 1,
Summit, NJ 07901, USA
Call: (866) 278-6653
Fax: (908) 273-9256

Be Familiar With The Types Of Casting Resins

The desire of man to do something innovative as well as eye-catching is the main reason behind the invention. It is not the story of the era. From centuries ago, people have developed several things to make their life comfortable and the process is continuing still today.

Molding and casting are the processes with which one can let his or her imagination run free. Resin casting is one among them. It is a method of plastic casting where a mold is generally filled with synthetic resin that later hardens.

Casting resin falls into three classes epoxy, polyester and polyurethane. Polyester resin is used for its mechanical properties. It is a contact product that requires no pressure to cure as well as can be cured from a fluid or solid state. The two varieties of polyurethane resins are opaque and water clear resin. Epoxy resin is more expansive than other types. It might take several hours to several days to completely cure.

polyurethanes resin casting

Each of the products comes with several advantages. Based on your requirement, you need to decide which one will be the right choice for you. EnvironMolds, LLC is a reputable shop in the field of molding and casting materials. They provide high-quality products at reasonable prices. If you want to get any of their products or have any queries, then feel free to call them at 1-866-278-6653.

Complete Mold Making With The Right Material

Sodium silicate is a multipurpose compound that is formed by the reaction of sodium carbonate along with the silicon dioxide in the molten form. The solution is used as a sealer, an adhesive, binder or deflocculant in cement, ceramics, lumber, textile, as well as automobiles.

Mainly the product is used in the manufacturing industry. The casting process involves pouring the molten metals in the sand molds. It is made with fine-grained sand which has been sieved with a hundred grade mesh.

Also familiar as water glass, the product is used in sand mold casting. All that you need to do is to apply a thin layer of the product between the two materials or on the surface and let it dry. The liquid will react under acidic conditions as well as form a hard glassy gel after drying.  It is a low-cost adhesive and for this, it is preferred by the artists.

Are you thinking from where to buy the product? There are several shops that offer it. However, if you want to get it from a reputable one, then choose EnvironMolds, LLC. They offer high-quality, environmentally-friendly products and that too at reasonable prices. Would you like to get any of the products? Do you have any queries? Then feel free to call at (866) 278-6653.