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How to prevent mgo board corrode steel?

Views:1480     Author:Site Editor     Publish Time: 2016-06-28      Origin:Site

Magnesium oxide board is a fireproof wall panel,famous for top fireproof degree,high strength and economic price.

Mgo board became a new star,brings huge impact to traditional wall panel,such as fiber cement board,Gypsum board,OSB and MDF.It is manufactured in China,export and sell in different countries,which involved in many world class big project.In recently,we found a lots of negative information about mgo board on internet,many users are afriad and question about mgo board.

Rockmax has been researched and developed chloride free mgo board over 10 years.Here is some useful information for share.

What is mgo board?

Magnesium oxide board or "mgo board" in short,it is flat wall panel,thickness range from 4mm-30mm

It consist of 3 element,(magnesium oxide),(salt) and (water).

Most of mgo board come from China,Why?

Magnesium oxide is one of the best fireproof material in the world.

Most of magnesium oxide mine located in Changbai Mountain,north part of China.

Chinese has experience of using magnesium concrete over hundred years.

How many kinds of mgo board?

MgO boards predominately come in three different types: 

magnesium oxychloride hydrate

magnesium oxysulfate hydrate

magnesium oxyphosphate hydrate

They are fomulated with different kind of salt.

Most of mgo board export from China is magnesium oxychloride hydrate type,

it is old technical,which contains uncontrollable chloride.

Mgo board(magnesium oxychloride hydrate) corrode steel,Why?

Metallic corrosion is the process of either stealing or donating electrons, when the electrons are stolen or donated, the metal atoms will dissolve in the water. Salt water is a the main conductor, so the rate of corrosion increases dramatically. When mgo board in high humidty enviroment(80%),inside chloride iron will dissolve and move toward water,when it contact with metal,unavoidale corrosion will happen on its surface. 

How to provent magnesium chloride board corrode steel?

3 options

1-Use stainess screw and stainless frame or aluminmium frame. 

2-Replace steel frame by wood frame and stainless screw

3-Laminate a plastic film on reverse that next to the steel frame

4-Dismantle magnesium chlrodie board,use chloride free mgo board instead. 

What would be happen if you use magnesium chloride board with steel frame or galvanized frame?

4 disavantages

1-screws and frame affect by chloride ions and get rust when moisture is high

2-panel damp and cry in rainy days,wet and dray cause plaster crack

3-panel get powery on the surface after frequent wet and dry

4-panel has risk of cracking at the joint after few months

How to check your mgo board,contains chloride or not?

2 options

1-Pour a cup of purified water,immerse some fine screw and mgo board sample.Check corrosion after 7 days.

2-Contact local testing lab,such as SGS. chloride content inspection,cost $300-400. It takes 7 working days.

Bad cases about mgo board(magnesium oxychloride hydrate) corrode steel

Number 1

A piece of mgo board fasten on steel frame by normal screw.

indoor condition,after 6 months,all the screw get rust and plenty of powder came out on the surface.

Screw lose strength.

IMG_3957 IMG_3956

Number 2

Mgo is a good product for airduct,A1 fireproof and light weight.

Magnesium chloride board 15mm-18mm has been widely use for ventlating duct in China.

It corrode steel and damp badly,because basement is wet and magnesium chloride can absorb moisture from air.

Now Chinese air duct association revised regulation of mgo air duct,require chloride content have to less than 1%

ventlate duct made of mgo
screw piont

Number 3

Exterior sheathing case.corrode frame badly,frame system destroyed after 4 year.screw lose strengh.

magnesium oxide board corrode steel2.jpg

magnesium board corrode steel.jpg

Mgo board corrode steel1.jpg

Mgo board corrode steel.jpg

Chinese Magnesium oxide board industry association issued new regulation for export mgo board

on June 11th,2018

All the chloride mgo board have to indicate

"This product shall not be directly contacted with metal parts without rust treatment"

In product specification and other sales documents.


1,ROCKMAX is new generation chloride free mgo board, do not have corrosion problem.

2,ROCKMAX is approved panel,test in full

3,ROCKMAX's material safety meet European "REACH",exclude 191 kinds of harmful material may effect health.

4,ROCKMAX provide guarrantee for steel frame system safty,compensate 200% on CNF price ,when chloride>0.5%

To choose a better mgo board,more green and safe,please kindly contact our sales team.

Finally we appeal all the mgo board distributors and end user stop using magnesium chloride board in steel frame system. 

Not Safe!

                                                                                              ROCKMAX TECHNICAL TEAM


About  RockMax™

Kunshan Boda Building Material Co., a new company established in 2010, which is professional producer of magnesium cement boards, our...
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