Types of Sand Used in Casting

Are you engaged in the sand casting business? Or, Do you want to have detailed knowledge about the different types of sand used in casting? And today, here comes a piece of good news. This guide will be the best source of information for your reference.

Firstly, let us have a relatively rough understanding of the sand casting. The sand casting process can nearly manufacture any parts or components that come in any shape. These finished products can be designed into very large sizes or into the form with internal passage channels. The term sand casting ( aka sand molded casting ) is a process of metal molded casting. Such a process is featured by the sand as the stuffing material.

Originated from more than 6,000 years ago, this technology has witnessed many progress and changes. Despite many changes, its basic principles remain unchanged. What has changed or evolved is the type of sand used in sand casting. Read on to learn more information about the three different types of sand used in casting.

Green Sand Casting

The term green sand exclusively describes the shallow marine sediment sand containing the greenish particles in a rounded shape. In the casting field, the green sand ( also known as the clay ) refers to a molding comprised of wet sand.

The green sand to form a molding usually consists of the following mixture: Sand: 75-85%; Bentonite Clay: 5-11%; Water: 2-4%; Other materials: 3-5%.
When catching the sight of the green sand, you may be seized by its unique green color. Such a phenomenon attributes to the different content of mineral glauconite. Featured the porous properties, the green sand proves to be useful in the absorption of water and some minerals. In the practical application, this feature will be conducive to boost the efficiency and convenience of irrigation and nutrients delivery.

Advantages of Green Sand in Casting

  • The green sand can be said the least costly material to mold.
  • Minimizing the heat tearing threat than other materials to mold.
  • As no experiencing baking, the green sand is less likely to deform in the course of making a mold.

Disadvantages of Green Sand in Casting

  • The surface of the product making from green sand is usually not smooth and in other words, rough and crude.
  • The surface gloss of products of green sand will suffer damage as its weight increases.
  • Being soft, it may lead to more casting defects, i.e. sand leftovers, sand holes.

Sodium Silicate Casting or Water Glass Casting

Sodium silicate mostly consists of the metasilicate. It is also known as water glass or liquid glass. It has a wide of applications, such as fire protection, textile, lumber handling, silica gel production. The water glass itself contains the iron impurities. Therefore, the products making from it are often tinted with green or blue.

In the casting process, if there is a need to make a cavity or a solid core, you need to first let the CO2 pass through the sodium silicate. And then, the sodium silicate will experience the dehydration, turning into a solid stuff. One important thing that should pay great attention to is that the sodium silicate should be mixed with other materials in the casting process. The purpose of this doing is to make the decomposition faster so as to take out the core with ease. If the proportion of the mixture is not reasonable, the core will get stuck in the casting, resulting in the failure of casting.

Advantages of Sodium Silicate in Casting

  • The sodium silicate or water glass is colorless, odorless, and non-poisonous.
  • It will not give off irritating or harmful gases in the casting process.
  • The sodium silicate produces no black and acid pollution.

Disadvantages of Sodium Slicate in Casting

  • The sodium silicate is not easy to collapse or take apart.
  • It has difficulty to reclaim the used sodium silicate. Plus, if not correctly handled, the water glass will cause pollution to our environment.

Resin Sand Casting

Resin sand refers to a mixture of quartz sand and resin. After mixing with other materials and burning, the resin sand will get extremely tough and solid. Therefore, we call the products making from the resin sand the hard mold, and the iron casting making from resin sand the resin sand casting.

After the process of mixing and heating, resin sand will turn into a solid mold that has a smooth surface. The solid feature indicates that there are fewer defects in the casting. However, everything has two sides. The cons of resin sand is a higher investment and slower production. Speaking in detail, it takes much more time to create a mold with the resin sand. Because you must fully mix each of sand mold ad then burn them, producing a perfect mold. Moreover, although the resin is a repeatedly consumed stuff, it is still necessary to replenish it constantly. This directly proves the fact that the resin sand is high cost.

Advantages of Resin Sand

  • The resin sand features a good fluidity and easy compaction property. The above feature opens the opportunity to adjust the ejection time.
  • After hardening, the resin sand boasts a high degree of strength. Such pro ensures that the resin sand is uneasy to be deformed in the following process.

Disadvantage of Resin Sand

  • The resin sand gives off an irritating odor in the process of molding and casting.
  • In comparison with the green sand, the resin sand is much more costly.


Now, I guess that you have had a rough understanding of the types of sand used in the casting process. No matter what kind of your company’s requirements, the expert team of Dawang casting could produce any metal parts or components. Plus, our technician can abet you to select the most suitable plan.

If you want to learn more, don’t hesitate to contact us or just leave a comment below. You’ll be accessible to have a thorough knowledge of casting. And they may be conducive to your specific needs.