Sodium Silicate Deflocculates Clay Slips

Posted by EnvironMolds , Labels: , , , , Friday, April 17, 2020 5:05 PM

Slip casting is a common technique used for the mass production of complicated ceramic items. It is made by mixing dry clay with water along with an effective deflocculant like sodium silicate.

Pottery is the common method used to make pots, dishes and other items using clay or other ceramic materials. The potter fashions the piece on the wheel with his hands and it is then fired to give it a hard and durable form. However, there is another technique for making hollow ceramic and porcelain articles in complex shapes that cannot be fashioned on a potter’s wheel. This is known as slip casting of clay, usually along with sodium silicate.


Slip casting is a simple technique of pouring thinned clay into a mold. The mold is filled to the brim and the clay is allowed to settle inside. This allows the slip to build a thin layer inside the mold after which the excess material is drained out. The amount of time the clay slip stays inside the mold will dictate the thickness of the cast.

The clay is allowed to cure and demolded once it starts to separate from the sides of the mold. Usually, slip casting is done in plaster molds as the porous plaster will absorb the water from the slip and allow for quick casting.

When it comes to making the slip for casting, people usually assume that it is done by mixing clay with water. However, this requires a lot of water which in turn will take a long time to shrink and dry. Moreover, the clay may not disperse properly in the slip and will settle at the bottom of the mixture. This is why a deflocculant like water glass (chemical name – sodium silicate) is mixed with the clay before adding water. This will thin the clay or reduce its viscosity by dispersing its particles and thus require much less water. But it should be kept in mind that excess sodium silicate will have an opposite effect and will actually make the clay thicker or flocculate it!

Top quality liquid sodium silicate can be sourced from EnvironMolds at Artmolds.com.

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Getting to Know KastEZ Polyurethane Resin

Posted by EnvironMolds , Labels: , , , , , Sunday, March 29, 2020 9:25 PM

There are various kinds of resins and each type comes in different formulations. KastEZ is a popular polyurethane resin formula that is commonly preferred by artists for their casting works.

Resins come in different types – polyester, epoxy and polyurethanes are the commonly used ones for making castings.

Of these, polyester resin is considered the most easy to use and the price is also reasonable. It cures to a hard form too. However, it emits noxious fumes which are quite dangerous for the user. Epoxy resin is also considered easy to use and is advised for beginners, primarily because of the longer pot time. It is safe to use, but cures soft which can make it difficult to handle.

It goes without saying that polyurethane resin is the most popular resin, even despite the comparatively higher price.

What works for polyurethane resin is that it is versatile and boasts of excellent strength, durability, elasticity and resistance to oils and other chemicals. It captures details well and generally cures to a hard form. However, varying the formulation of the resin can yield varying properties from a soft pliable rubber to a very hard and rigid plastic. It comes in both opaque and water clear forms to suit different applications. The resin is commonly preferred for general mold making and casting. Some of the polyurethanes may require the use of a respirator due to a mildly noxious odor.

The EnvironMolds MoldQuik is an example of a pliable polyurethane whereas KastEZ Resin cures to form an opaque, hard plastic casting.
The latter is a two-part polyurethane casting resin used in 1 to 1 ratio by volume. It is available in 16 oz, 2 quarts and 2 gallons packaging. Initially, when both the catalyst and base are added together, the resin will look cloudy. It will begin to clear with the mixing. A thorough mixing while properly scraping the sides and bottom will cause the resin to become clear and this is when it is ready to use.

KastEZ resin is easy to use. Simply pour the resin into the mold and allow it to set. It cures at room temperature – within 10 minutes itself. A release agent is required, but demolding is a straightforward process as well.

The cast will be lightweight and will form a hard plastic with an ivory white color. Special resin dyes have to be used to impart a specific color to the resin. The colorant can be easily mixed into the resin to get the desired color. Proper mixing will give a uniform color while a few strokes will create a marbleized effect. The dye will not affect the pot life, demold time or even the inherent properties of the cured plastic in any manner.

This same resin can in fact be cast in both rigid and flexible molds. Some of the most common uses are figurines, displays, rapid prototypes, special effects and sculpture reproductions. In fact, KastEZ polyurethane resin is the right choice for almost any application.

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The Many Uses and Forms of Plaster

Posted by EnvironMolds , Labels: , , , , , Friday, March 13, 2020 2:14 AM

Plaster is a simple powder that can be made in various forms and used for different purposes. The usage varies from smoothening walls and ceilings to decorating them to make castings of art works.

Plaster is a commonly used material that enjoys varied uses. The most common usage is in construction to give a smooth surface to coarse walls and ceilings. There are various kinds of plaster – like cement, lime and gypsum or even clay. Plaster is basically a dry powder with one of the above materials being used as a binder. It is mixed with water to form a workable paste. It slowly solidifies on exposure to air to form a hard and stiff covering on the external or internal walls.
Apart from this, plaster is also used to make false ceilings and in decorative architecture. Complex shapes and carvings can be created on walls and ceilings using plaster of Paris. This is basically gypsum deposits mined in Paris, and hence the name.

Plaster enjoys great patronage in the art world too. It can be used to replicate art works and make casts using quality products like CastRite Art Casting Stone. Art plaster is a special type of plaster – regular plaster cannot be used for casting as it does not hold details well and will also tend to become chalky and flaky over time. Moreover, it is hydroscopic in nature and will turn into an irreversible solid form on the slightest exposure to moisture.

Casting calls for a hard casting plaster that can capture the fine details from the mold and set fairly quickly. Yet, it will allow carving and tooling as needed. What’s more, this type of plaster can also be used to make molds.

Plaster can be cast into various mold materials like clay, alginate, rubber, cement, wood, etc. However, care should be taken as the chemical reaction of plaster with water tends to release heat. This is why plaster is not usually used directly on the skin. Plaster infused bandages are a good option for making basic body molds and shell molds.

CastRite Art Casting Stone can be easily sourced from the EnvironMolds website, Artmolds.com.

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Capturing Tiny Memories of a Baby with Life Casting

Posted by EnvironMolds , Labels: , , , , Tuesday, February 18, 2020 4:06 AM

A little one will not be so little for very long. The best way to capture the baby’s moments is to seal them in a life cast. Casts of a baby’s hands, feet or even the bottom will make for a lovely memory.

A child is a baby for hardly any time. The initial months and years may be frenzied, but very soon the time will seem to have flown away. Before the parents realize, the baby has grown into a toddler and will bloom into a young boy or girl. The parents find themselves longing to cling on to these precious moments even as they delight in watching their offspring grow into mature and independent adults.

Photographs and videos can never do justice when a parent wants to really ‘hold on to’ a quickly growing child. How about a life cast of the baby with a brass name plate instead?

Indeed, life casts of a newborn or infant’s hands and feet are very popular keepsakes among the new parents of today. Even the baby’s cute bottom can be captured in a naughty life cast. These make for a wonderful memory of the baby that will be cherished forever. The baby life casts can also be gifted to a grandparent or other close family member as an emotionally powerful keepsake of the little one.

Making the Baby Cast

Capturing a body mold of the baby is a simple and straightforward process. It works easily with newborns as they cannot move or fidget at all. The mold can be made while the baby is asleep itself.

Experienced life casting artists can work with infants and toddlers too. The body mold doesn’t take long to set and all it takes is holding the child in place for some time to keep him or her from squirming.

The parents need not worry about the material affecting the child’s soft and sensitive skin either. Alginate is a natural, organic material that is derived from seaweed and is totally safe for the skin. The artist will still do a patch test first to check for any reaction on the skin.

The alginate paste is first applied over the body part to be cast and then the mold is reinforced with plaster bandages. It sets fairly quickly and can be demolded easily. The artist will first apply petroleum jelly on the skin to ensure an easy removal.

Once the mold is cured, the life cast is usually made with plaster. It is even possible to make a fake metal or stone life cast using cold casting powders. The finished cast can be framed and finished with name plates engraved with the name of the baby, the date and so on.

In fact, it is even possible to go a step up with a parent and child casting. Hands intertwined or overlapping each other or joined together in prayer – there are numerous options and the only limit is your imagination!

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CastRite Art Casting Stone For Plaster Casts

Posted by EnvironMolds , Labels: , , , , , Tuesday, January 28, 2020 10:04 PM

A wide variety of plaster powders are available in the market – each with their own functions and properties. Choosing the right option for making a cast becomes difficult for novice artists.

The art world is choc-a-bloc with varied materials for making molds and casts. The choice ranges from simple clay, wax and plaster to more sophisticated options like resins, latex rubbers, silicone rubbers and more. Even when it comes to using plaster, mold makers and casting artists are often flummoxed whether they should use regular plaster of Paris or the more refined casting stone powders available in art stores.

Well, fact of the matter is that generic plaster tends to be chalky and fails to hold details well. Casts made from this powder will be prone to chipping and cracking too. On the other hand, casting stone powders are made with gypsum that is especially heat treated to make it suitable for fine art casting.




































CastRite Art Casting Stone is a top quality, high definition casting stone powder offered by EnvironMolds. It is a popular material of choice for making art castings of all types. It is easy to work with, gives a natural bright white finish, holds finishes well and is extremely durable.

The CastRite powder is a highly dense formula that is suitable for making casts from alginate, resin and silicone molds. It can be cast into plaster bandages as well. Apart from casts, it is also commonly used for making shell molds for latex slip castings and backup flexible molds. At times, fiberglass fiber is added to the mold powder for additional strength.

How to use?

Take 2 equal parts of CastRite Art Casting Stone powder and 1 part of water by volume. First pour the water into a mixing container and then add the casting stone powder very slowly. Mix with a stirring stick while scraping the sides and bottom of the container till the mixture becomes thick and creamy. The material is ready for pouring into the mold for making the cast. This formula inherently has minimum air bubbles; even these can be eliminated by rotating the mold slowly in all directions.

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Safety Precautions When Working With Resins

Posted by EnvironMolds , Labels: , , , , , Tuesday, January 14, 2020 4:00 AM

Resin is a commonly used material for making different types of casts. It is fun to work with especially when making artistic jewelry and other casts. However, some safety measures are needed.

Resin is a viscous material that slowly hardens and sets solid in the form of a plastic. It comes in various types – like epoxy, polyester and polyurethanes. Resin casting is very popular among professional artists and novices alike.

The uses are varied ranging from artistic jewelry and faux metal casts to small parts in manufacturing industries to 3D printing to even gluing things together.

While resin lends itself well to many a use, the artist has to handle the material carefully and keep the following precautions in mind:
  • Some resins are considered volatile chemicals and should not be allowed to come into contact with the bare skin. Even the catalyst can prove to be risky. Always wear protective gloves when working with resin. Use a plastic apron to avoid ruining the clothes with spilled resin.
  • It is better to wear safety goggles and use a respirator when working with large quantities of resin. This will help shield against the noxious fumes.
  • The work area should be properly ventilated with open windows and an exhaust fan.
  • It is better to spread some wax paper on the work surface before using resin. As resin will not stick to the wax paper, it will be easy to clean. The dried resin can be simply peeled off from some materials; else it can be cleaned with rubbing alcohol.
  • But never use the alcohol or other solvent in case the resin comes in contact with the skin. Try to wipe it off immediately with baby wipes. Sticky resin can be scrubbed off with soap or a pumice stone.
  • Maintaining the ideal environment is crucial when working with resin. 70°F is considered the standard temperature as the resin fails to cure properly if the studio is hotter or cooler. Therefore, an air conditioner or heater may be required.
  • The resin and hardener should be measured accurately using measuring cups. Do not go by ballpark approximations as it can again affect the curing of the resin.
  • The materials should be mixed carefully and thoroughly using stir stix for a couple of minutes to ensure a uniform mix. However, overmixing can also introduce air bubbles into the casting material.
  • Some air is bound to get trapped into the resin and will show up on the surface of the cast. This can be popped with a needle or heat gun. Casting in a pressure pot is ideal for eliminating the air bubbles.
  • The resin is likely to attract dust or animal hair while it cures and will end up ruining the resin casting. Keep the studio clean and cover the cast with a clear dome while it cures.
  • Above all, follow the manufacturer’s instructions and safety precautions to the T.

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Eliminating Air Bubbles in Molds and Casts

Posted by EnvironMolds , Labels: , , , , , Friday, December 27, 2019 3:40 AM

There are different mold making and casting equipment that can be used to make bubble-free molds and casts. The suitability of a given equipment depends on the nature of the material and other factors.

One of the most taxing things when making a mold or cast is dealing with the air bubbles. Some air is bound to get trapped into the material no matter how carefully the artist mixes and pours the material. Once set, this shows up as unsightly warts on the surface of the mold/cast and makes it mostly unusable.

Fortunately, there are various tricks and even mechanical equipment for eliminating these pesky air bubbles. While pouring the material in a thin and steady stream from a corner and pricking the bubbles with a pin can help to some extent, it is always better to use an apparatus like vibrating table, pressure pot or a vacuum pump with vacuum chamber.

This brings us to the question – which of these equipment is the most effective in getting rid of the trapped air in the mold making or casting materials?

Well, there is no single-point solution as such.

A vibrating table uses the simple technique of pulsating the material to shake out the bubbles. This will reduce the bubbles but cannot deair the material completely. Careful pouring will reduce the propensity of bubbles for sure.

On the other hand, a pressure pot is best suitable for materials that will cure to a rigid form. Like resins for example. It is better to avoid pressure casting soft rubbers as the air bubbles are bound to return once the mold or cast is exposed to normal air pressure. A rubber mold or cast is even likely to collapse in the areas where air remains trapped under the surface.

A vacuum chamber with pump is best suited for removing air from the rubber materials. Artists usually leave the rubber mold or cast to cure in the vacuum inside the chamber and the air will not return later!

All mold making and casting materials and equipment can be easily sourced from the EnvironMolds website, https://www.artmolds.com.

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