What is the Difference between Hydrocal and Ultracal?


Is there a difference between hydrocal and ultracal? Choosing a material for a specific project that you are working on can sometimes be confusing because of their similarity. Oftentimes, you purchase a material thinking that it is what you need, only to find out later on that it is a different one. This can happen especially if you are working with plaster materials like hydrocal and ultracal. To help you get started, we will discuss the differences between both materials below.

What is the difference between Hydrocal and Ultracal? The difference between hydrocal and ultracal is that ultracal is harder and denser. On the other hand, hydrocal is a casting plaster that does an excellent job when it comes to holding detail. While hydrocal is easier to work with when it comes to posting casting projects, ultracal is more durable.

Hydrocal and ultracal are gypsum cement and both have different properties. Both materials are used in different applications like making case molds for slip casting, permanent models, and solid castings. Check out the rest of the article below to learn more about the materials.

Hydrocal Vs Ultracal

Hydrocal is made for making solid and hollow castings. This material is suitable for many color pigments. Make sure that you read and follow the handling and directions on how to use hydrocal according to what is written in the package. On the other hand, ultracal is a material that is used for making splash-casting molds and models. It is water-soluble so it is easier to clean. Moreover, ultracal is noncombustible.

Is Hydrocal Stronger than Ultracal?

Ultracal is stringer and harder as compared to hydrocal. They have the lowest setting expansion as compared to any gypsum cement. Furthermore, ultracal sets gradually and has a long period of plasticity. Ultracal is best used for splash-casting molds.

What is Hydrocal?

Hydrocal is versatile gypsum cement that is used for hollow and solid castings. This material is specifically designed for thin sections. Take note that hydrocal has a high green strength which allows it to lessen breakage during removal of the casting from the molds. Hydrocal has a very white color. For a more in-depth discussion about this topic, you can check out this article that we have shared titled, what is hydrocal? We have shared helpful tips and ideas that you can refer to.

Why is Hydrocal Made of?

Hydrocal is mainly composed of plaster of Paris with a small amount of Portland cement. Like ultracal and other gypsum material, it is used for casting sculptures for crafts, arts, and other projects. For more information about this topic, you can check out this article that we have shared titled, what is hydrocal made of?

What are the Uses of Hydrocal?

The main use of hydrocal is casting sculptures and making molds for arts and crafts. They are a popular choice because they are easy to use and are also flexible. As compared to ultracal, hydrocal is softer so you can be able to work on it longer. On the other hand, it is not as durable as compared to ultracal.

What is Ultracal?

Ultracal is gypsum cement that has low absorption and is usually used for case molds. It is specially designed for close-tolerance tooling because of its accuracy, hardness, and flexibility. Ultracal is a good choice if your work needs accuracy and a good amount of surface hardness.

✅ Video – What is Ultracal? | Guide for Beginners

CustomTerrain shared the video below on YouTube. It discusses what ultracal is. In the video, how to mix and use ultracal is discussed. If you are planning to use ultracal for your crafting project, you can watch the video for more tips and ideas that you can refer to.

How to Mix Ultracal?

Ultracal is commonly used for creating molds with industrial patterns only. Mixing ultracal with water produces a chemical reaction. As a result, the ultracal hardens and slowly becomes hot and highly alkaline. Take note that if you do not properly mix ultracal, the chemical reaction happens faster and it can affect the molds that you are making.

Do not use ultracal when making molds that enclose any part of the body. Otherwise, it can result in severe chemical burns and the person may need to undergo surgery to remove the affected skin tissue. Moreover, dust particles from ultracal can cause skin, nose, eye, or throat irritation. Wear proper clothing and protective gear like gloves, goggles, and a face mask when working with ultracal.

How Long Does Ultracal Take to Set?

The average time that it takes for ultracal to set is about 25 to 35 minutes. The amount of ultracal that is used and its ratio with the water as well as the mixing process can also affect its setting time.

Mixing Plaster and Water

When it comes to mixing plaster and water, there are a few steps that should be done. The best plaster mix is the one wherein the plaster particles completely dissolve in the water. This creates uniform slurry. Moreover, when making plaster casting, make sure that you use pure water. Avoid using water that is treated. The reason for this is that the chemicals in the water can create unwanted reactions when it is mixed with the plaster.

Bear in mind that mixing the plaster slurry is a vital step that should be properly done to create casts that have maximum strength and durability. Moreover, how long you mix the slurry will affect the setting time. For instance, shorter mixing times will allow the plaster to set slowly.

Why Use Utracal or Hydrocal?

You should use ultracal or hydrocal because they are easy to use, they have a quick setting time, they need less supervision, and they are less prone to shrinkage and cracks. Let us learn more about this below.

Easy to Use

Hydrocal and ultracal are easy to use. All that you need to do is to follow the instructions written on the package on how to properly mix and handle both materials. They are flexible and can be used for various arts and craft projects. Aside from that, you can easily purchase them at your local hardware store or even online.

Does Not Crack

Another reason why it is ideal to use hydrocal and ultracal is that they do not crack. They produce less heat as compared to other products. Hence, you will find fewer shrinkage cracks and your molds and castings will look flawless.

Sets Quickly

Hydrocal and ultracal sets quickly. Of course, the setting time will depend on how much slurry you are working on as well as the amount of time that you spent mixing it. They can be set at about 25 to 35 minutes.

No Need to Supervise

If you are working with other types of plaster, they need to be supervised to achieve the best results. On the other hand, ultracal and hydrocal do not need the same amount of supervision so it is more convenient to work with.

High Performance

Hydrocal and ultracal have high performance. Once they have set and are fully fried, they have the best strength. Aside from that, they are also durable and lightweight.

What are the Uses of Ultracal?

Ultracal can be used in a wide array of applications. They are generally used for sculpture, patterns, commercial casts, and figurines. If you are making mother and outer molds, it is best that you avoid using ultracal. Moreover, it is not recommended for outdoor use. Ultracal is specially designed for strength and casting detail. It is 30 to 50 percent harder as compared to other casting plaster.

Can You Heat Ultracal?

You can heat ultracal, but you need to follow heating instructions. Generally, the maximum temperature at Ultracal molds can be heated safely is 120 °Fahrenheit. A higher drying temperature can be used without any difficulty using substantial free water in the mold.

Is Hydrocal Stronger than Plaster?

Hydrocal is stronger as compared to plaster of Paris. Aside from that, it also takes a lot more detail. Hydrocal does not slough off which makes it easier to work with and more durable. Take note that plaster that does not slough off is vital when it comes to making long life scenery. Plaster that sloughs off can lead to dusting and chipping. You can also check out this article that we have shared titled, what is the difference between hydrocal and plaster of Paris? We have shared an in-depth discussion about the topic.

Conclusion

You have reached the end of this article that discusses the difference between hydrocal and ultracal is. We have found out that ultracal is harder and denser as compared to hydrocal. Both can be used in various art and craft projects. With the many plaster materials that are available on the market, it is vital that you know what you are working with. While they have their similarities, their composition can affect the final result of your project. We hope that you have learned more about ultracal and hydrocal after reading this article that we have shared. Thank you for reading!

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