Soluble salts are a leading cause of corrosion and premature coating failure on metallic surfaces. Here we provide a brief overview as to what soluble salts are, and a cost-effective solution for removal.
What Are Soluble Salts?
Soluble salt is an umbrella term for a range of minerals found naturally in the world around us. They include chlorides, sulphates, potassium, sodium, magnesium and nitrates, alongside other non-metallic compounds. It is widely documented and acknowledged that soluble salts, particularly chlorides and sulphates, initiate and accelerate corrosion of steel and become deeply embedded within iron corrosion products. They are also capable of causing breakdown of a coating by the mechanism of osmotic blistering – a phenomenon in which two substances attempt to reach equilibrium through a semi-permeable membrane such as a coating. A large number of studies have been undertaken of how these substances are deposited on the steel, how they catalyse and effect the corrosion process and their interaction with coatings. What is not disputed is the detrimental effect these have on coating performance.
Soluble Salt Removal
There are a several ways to remove soluble salts and the industry has seen an increase in ‘wonder’ products in the last decade that claim to remove or eradicate soluble salts completely. However, here at KUE Group we have utilised our proven ‘System 918 Variable Low-Pressure Wet Abrasive Blasting’ technique successfully for over 40 years.
KUE Group ‘System 918’
‘System 918 Variable Low-Pressure Wet Abrasive Blasting Technique’ has the unique ability to be infinitely varied by controlling not only the air pressure but also water and abrasive volumes. With this fine control it is possible to achieve optimum results in such diverse fields as the selective removal of individual coats of paint or coating, or the blasting back to a true BS EN ISO 8501-1:2007 Sa3 (blast cleaning to visually clean steel – also known as white metal), free of soluble salts. With comparatively high production rates prior to coating ‘System 918’ has been proven to be an effective method of removing soluble corrosion salts from steel substrates, thus ensuring that the threat of substrate corrosion beneath an ostensibly sound coating film does not occur. These factors, combined with the system’s intrinsic safety, allow for its use in flammable areas such as gas plants and refineries. This, together with low site down factor, makes ‘System 918’ ideal for surface preparation.
Find Out More
For a longer and more cost-effective life for your coatings, consider a surface treatment that actively removes soluble salts. To find out more about our solutions or discuss your options, please call 01274 721188, or email sales@kuegroup.com.
