I. What Is Halogenide?

Magnesium oxide board is an upgraded product which replaces t raditional wooden board and gypsum board. It is Eco-friendly, well fire-resistant and low-cost. However, it also has weakness, which is often overlooked by users, namely halogenide. When it occurs, you can see water droplets lying on the surface of the board. It looks like the board is “sweating”. The “sweats” will corrupt board, which may crack and even fall apart over time.

How to Keep MgO Board from Sweating?

“Sweating” MgO board

II. Ways to Prevent Halogenide

The main reason causing halogenide is excess free available chlorine in the board. Factories and research institutes have made a lot of efforts to ensure the removal of excess free available chlorine. Currently there are two methods:

One method is to add the so-called halogenide-reducing agent. Many factories in China do not have enough space for board drying. In order to save costs and speed up the drying, they use this agent to wrap the free available chlorine, making it temporarily separated from outside. However, free available chlorine is always there in the boards. Once a special condition is encountered or the agent loses its sealing properties over time, the free available chlorine will escape and cause halogenide.

Another method is soaking, which is an outstanding feature of our boards. Soaking is the only way that has been proven safe and halogenide resistant for many years. We are the first company to introduce MgO boards to Europe. Since 2004 we have been exporting a large number of MgO boards to European countries. We have never received complaints about the quality or “sweating” issues from customers.

III. How Does the Soaking Work?

After the secondary curing is completed, the board is immersed in the pool and soaked for 12 hours (adjust soaking times and duration according to the thickness) before drying. It is called the displacement method, that is, displace the excess free available chlorine with clean water.

Mgo board soaking process


In order to show the effect of this method, we made the below test. From left to right, the three cups shown in the picture are filled with bittern solution, water left after soaking and clean water. It can be seen from the color that there is a significant difference. The test result shows that the baume degree of the three cups of solution is 23, 2, 0.

How to Keep MgO Board from Sweating?

IV. Two Methods to Test If the Board Is Halogenide Resistant

There are two ways to test if the board is halogenide resistant.

1. Observation Method. Click here to see details.

2. Water Soluble Chloride Test. Click here to see details.