The abrasives market is a complex one, especially considering the vast range of cutting and grinding discs available for specific applications. At the same time, this complex mix of products can be easily navigated if asking the right questions.

What makes a cutting disc suitable for a specific application? When do we use what product for a specific material type?  How do I know this product is safe? And what happens if I use these products for anything other than its intended purpose and how much of a difference does this make? 

When it comes to working with hand tools for abrasive discs, powered or manual, safety protocols should be the starting point. Before using any abrasive disc, the label should be read, and a visual inspection of the abrasive should be done to establish if it is suitable for use.  

Understanding Safety Certifications on Abrasive Product Labels 

Certified abrasive products carry the international OSA mark (Organisation for Safety of Abrasives) on their label, having fulfilled very strict measures, ensuring operator safety and traceability back to the manufacturer of the product, providing peace of mind. If the label also displays the EN and ISO marks, it further indicates that the product is manufactured according to local and or international standards.  

Guidelines for Safe and Effective Use of Abrasive Discs 

Finding a suitable abrasive product is quite easy as both material application and application type like angle grinding or free hand cutting, is indicated on the disc label. It is important to use abrasive discs only for their intended purpose. Cutting discs for instance, are designed to be used perpendicular to the surface and are not intended for grinding. Deviation from the correct usage may result in product failure and may cause harm to the operator or others. High quality, premium abrasives manufactured to the above standards are engineered to ensure safety, however incorrect usage of the product can still cause failure of the product and or harm to the operator.   

Although material application is usually clearly marked, it is important to note when a disc label is marked for “Steel” or “Metal” that it is suitable for “ferrous metals” and not ideal for “non-ferrous metals”.  Aluminium, being a non-ferrous metal, has very different characteristics to mild or normal carbon steels. Using a steel cutting disc on Aluminium will result in the edge of the disc becoming clogged and heating up, causing stress and possible disc failure and breakage. Another important factor to consider is material contamination, especially when working with Stainless Steel and Aluminium. The label should identify a product as being suitable for this material but should also indicate that it is contaminant free.   

Abrasive cutting discs are manufactured using Aluminium Oxide, Silicon Carbide, Zirconium or Ceramic grains where each grain type suites a specific material application and if used incorrectly, may be completely ineffective or dangerous. 

Key Considerations for Selecting and Using Abrasive Discs Safely 

The standard range of products may contain normal manufacturing additives like Iron, Sulphur, and Chlorine, which can cause unwanted oxidation and “rusting” in both Stainless Steel and Aluminium. If working with multiple materials, great care should be taken to not use the same disc on all materials – either use one disc per material or move from Stainless Steel to mild steel to avoid cross contamination. 

 Another important factor on abrasive disc labels to consider though often overlooked, are the safety pictograms displaying the required PPE (Personal Protective Equipment) like safety goggles, ear and eye protection as well as gloves to be worn when using these products. 

In any application, when in doubt, we recommend you contact the manufacturer for guidance on making the correct choice when it comes to abrasives. 

Courtesy of Grinding Techniques | +27 11 271 6400 | [email protected] | www.grindtech.com  

The cost of docking a vessel or ship for repairs is extremely expensive. Not only are the docking (layup) fees to be considered, but the cost of qualified repair staff along with the various other consumable costs, and the potential loss of income is something to be noted, therefore a multitude of criteria must be considered before deciding to dock a vessel for repairs. 

There are however several reasons why a ship would be docked for building maintenance, a specific reason is that ships have anti fouling paint to reduce the number of algae and barnacles that attach themselves to the vessel. Over time the anti-fouling efficacy is reduced, and it must be removed and repainted. 

Local Manufacturer: Grinding Techniques Pride

Being a proud local manufacturer and supplier of specialised abrasive products, we can offer a wide range of cutting and grinding tools for almost every kind of application – actively, objectively, and reliably. When choosing abrasives for a vessel at hand requiring maintenance, it is important to obtain the best value for money and minimise the amount of time spent on each operation to return the vessel back to service in the shortest time possible. 

Learn more: Grinding Techniques Cutting Products 

Maintenance starts with cleaning  

The Superflex 115×22.23mm rough cleaning disc will quickly and efficiently remove algae and barnacles from the hull with little to no stock removal from the original base material. 

Once this operation is complete, our range of Velcro discs – available in various grits will remove and sand down any remaining anti fouling paint left on the surface of the hull, ensuring the surface is prepared and ready for a fresh coat of anti-fouling paint to be sprayed on in no time. 

Steel hulls can and will inevitably become damaged and will rust during its operational life. For severe rust, our range of Superflex flap discs can remove the rust quickly and efficiently. This will ensure that the surface is correctly prepared for further operations.  

Where there has been severe damage to the steel hull and a portion of the metal must be removed to weld new metal replacement plates in, our full range of Superflex 115mm to 230mm steel cutting discs (dependent on the thickness of the material) may be utilised to efficiently cut away the damaged portion.  

Once the damaged section has been cut out, our Superflex range of steel grinding discs will quickly and efficiently remove any burrs and prepare the hull for the new plate to be welded into place. Our grinding discs or flap disc range are ready to clean up the weld and blend it into the rest of the material. 

Building Maintenance Procedure 

For damaged aluminium hulls, the same procedure of preparation on steel hulls will be followed except the abrasives used would be our Superflex Non-Ferrous range specifically designed for use on aluminium.   

To cut out the damaged aluminium portion, our range of Superflex aluminium 115mm to 230mm cutting discs will be used. These discs are specifically designed to cut aluminium without contaminating the metal. Our Superflex line of Premium Non-Ferrous flap discs is used to effectively integrate the weld once the plate has been welded into position. Once more, velcro discs can be used to even out the surface before painting.  

Final Thoughts on Sea Vessels Maintenance 

It is always important to ensure your required abrasives are task specific to fully take benefit of the product optimisation to obtain value for money. Contact us for the latest innovation in specialised abrasives. Training and technical assistance is available from our product specialists who are ready to provide solutions to all your questions and processing issues. 

Tel: +27 11 271 6400 | [email protected] | www.grindtech.com