Hydrocal is a strong and durable material that is easy to work with, but how long does it take to cure? Making sure that the hydrocal casting is dry before demolding is important to make sure that you will not damage the casts. Aside from that molds that are made from hydrocal should be kept dry especially when it is used regularly to avoid cracks and damages. Let us learn more about the topic below.
How long does it take for Hydrocal to cure? When manually mixed, the average setting time for hydrocal is between 25 to 35 minutes. You need to make sure that the hydrocal is completely cured before you remove it from the mold. This usually takes up to 24 hours depending on how thick the cast is.
Drying is an important step in making casts and other objects from hydrocal. The drying process is simple just as long as the proper conditions are maintained. The thickness of the hydrocal cast and the temperature of the room where it is kept are some of the factors that affect the setting time.
How do you know if the Hydrocal Mold is Dry?
One of the things that you need to watch out for to find out if the hydrocal mold is dry is the color. A dry hydrocal mold has a bone white color. If it has slightly darker or cream-colored, it is still wet. Another way to find out is by touching the mold. If it is slightly cold when you touch it, it is still wet. For a hydrocal plaster to be thoroughly dry, all the water that you use during the mixing process should evaporate.
How Long Should Hydrocal Mold Dry before Flipping Over?
Let the hydrocal mold rest for about 24 hours before you flip it over to another side. You need to wait about 72 hours if you want it to be completely cured. De-molding the hydrocal before it dries can damage its surface and also cause breakage. Take note that the longer hydrocal can cure, the harder it will be. Hydrocal sets quickly. If you are planning to paint the hydrocal, it first needs to cure for a few days. Why hydrocal sets quickly, curing can take some time. You can also check out this article that discusses what hydrocal is made of. We have shared useful information about the composition of hydrocal.
How Long Does Casting Plaster Take to Dry?
Casting plaster can take a few minutes or a few hours to dry depending on some factors. For instance, the size of the cast can affect how long it will dry. Smaller casts take a few minutes to dry a few hours to cure. On the other hand, a large cast could take a few hours to dry and a few days to cure.
How to Dry Hydrocal Mold
There are different factors that affect how hydrocal molds dry. Aside from the size of the mold, the room temperature also determines how long it will dry. Hydrocal mold will dry through exposure to air at room temperature. On the other hand, they can also be dried in a warm oven. Be careful when using the oven to dry hydrocal molds because high temperatures can cause them to crack.
Number of Molds
When it comes to drying hydrocal molds, it has the same methods as drying clayware. On the other hand, drying hydrocal should be urgent especially if you will use the mold many times. If you are using room temperature for drying, you need to have many molds in stock if you are doing multiple casts of the same mold.
Using the Dryer
If you are using a dryer to dry hydrocal molds, see to it that the temperature inside the dryer does not exceed 50 degrees centigrade. You can use an ordinary thermometer inside the dryer to check the temperature. Take note that wet molds do not become hot even if they are exposed to air that is above 50 degrees centigrade. On the other hand, dry molds can get damaged when exposed to temperatures above 50 degrees centigrade which can lead to cracks. Hence, it is recommended that you remove the molds from the dryer while they are still damp.
Recalcination of Molds
It is vital that hydrocal should not be overheated. Otherwise, it will begin to recalcine. Bear in mind that gypsum will begin to calcine when exposed to a temperature of about 100 degrees centigrade. When exposed to temperatures above 50 degrees centigrade, the hydrocal molds will soften and can have chalky edges. As a result, it will weaken the molds and lessen their durability.
Deflocculants
If you are using hydrocal molds for slip casting, they should be dried only from the outer surface. Meaning, they should be assembled so that only a little water will evaporate from the surface of the inner mold. Bear in mind that the casting slip, as well as the water in the casting molds, have deflocculants. These deflocculants can remain on the surface of the mold even if the water evaporates. Moreover, deflocculants attack plaster. Because of this, it is ideal that they are concentrated on the outside of the mold to avoid damages.
Tips in Drying Hydrocal Mold
When drying hydrocal mold, choosing a warm, draft-free, and dry location is very important. Make sure that the rack where you place the mold has plenty of room for air to flow around. Prevent the mold from becoming powdery by keeping it from temperatures of 120 degrees Fahrenheit or above. To help the mold dry faster, you can place an electric fan near it. However, make sure that you flip the mold every few hours so that all sides will be dried. It is recommended that the mold should be left to dry for about 24 hours or more. How long the mold takes to dry will have to depend on how thick it is. Thicker and heavier molds take longer to dry as compared to the lighter ones.
✅ Video – Molding a Mask in Hydrocal
StiltbeastStudios shared the video below on YouTube. It shows how to mold a mask in hydrocal. In the video, the methods, tips, and techniques in casting hydrocal is discussed. You can watch the visual demonstration below for more tips and ideas.
Why Hydrocal Takes so Long to Dry?
Different factors affect how long hydrocal takes to dry. Dampness and high levels of moisture in the air can cause hydrocal to dry longer. Moreover, hydrocal can take a few days or weeks to cure when exposed under extreme conditions of high humidity. Moreover, another factor that affects how long hydrocal dries is its thickness. Thick and heavy hydrocal molds and casts hold more water which makes them longer to dry out. Aside from that, cooler temperatures can slow down the curing process.
Is Hydrocal Stronger than Plaster of Paris?
Hydrocal is much stronger and more durable as compared to plaster of Paris. Another advantage of hydrocal is that it can be able to take a lot of detail. Moreover, hydrocal does not slough off which makes them an ideal choice for making a long-life scenery base. Plaster of Paris sloughs off which results in dust and chips on the plaster. For more information about this topic, you can check out this article titled, is hydrocal stronger than plaster of Paris? We have shared an in-depth discussion about the topic.
How Long Does it Take for Plaster to Set Up or Harden?
Usually, plaster can set and harden in about 30 to 45 minutes. However, different factors will affect the setting time. Thicker and heavier plaster casts or molds take longer to dry as compared to the thinner and lightweight ones. You can tell if the plaster has set if it feels cool when you touch it. Take note that the setting time is not the same as the curing time. For the plaster to cure, it can take about 48 to 72 hours or more.
How Can I Speed Up Plaster Drying?
You can speed up the drying of plaster by enhancing and increasing ventilation in the room. You can open the windows to let air inside. You can also use a fan or a dehumidifier to remove moisture in the atmosphere. If you want a faster drying time, you can place the plaster inside the oven. On the other hand, you need to be very careful when using the oven because exposure to high temperatures can cause the plaster to crack. You can also check out this article that discusses if hydrocal expands. We have shared tips and ideas that you can refer to.
Conclusion
You have reached the end of this article that discusses how long it takes for hydrocal to cure. We have found out that different factor like the thickness of the plaster as well as environment temperature affects how long it takes for the hydrocal to dry. Moreover, we have shared tips and ideas on how to dry hydrocal that you can refer to. Thank you for reading!