From Prep to Finish: A Guide To Welding Abrasive Techniques

Any professional welder knows that abrasives play a critical role in welding and fabrication. Abrasive tools and techniques are employed in almost every stage to enhance the process from preparation to finishing.
But what exactly do these techniques involve? And how does the selection of abrasive tools impact the quality of the final product? Read our guide on welding abrasive techniques to find out.

Preparation: Cutting, Beveling, and Cleaning

Cutting

Before the first weld joint is created, the workpieces must be cut into exact shapes and sizes to reduce the risk of defects later on in the welding process. Several abrasive techniques are employed to contour and shape these stock materials.
A cutoff wheel, such as the PFERD 4-1/2″ x 3/32″ Cut-Off Wheel, for example, is used to enhance the speed and efficiency of the cutting process, especially when working with very hard and thick metal pieces.

Beveling

Each metal piece must also be beveled. Beveling involves cutting an angled slope on a piece’s edge to improve the surface area of a weld site and create stronger welds. Abrasive tools that can be used to prepare and create bevels include cutoff discs, abrasive belts, or depressed center grinding wheels such as the Flexovit Type 27.

Cleaning

Once the material is cut and beveled, it must be cleaned. The surface may contain several substances—from oil and paint to rust and mill scale. If left unattended, these substances can contaminate a weld.
Abrasive cleaning techniques are recommended for cleaning as they are capable of getting rid of almost all contaminants and reduce the costs of having to carry out multiple cleaning processes.
Some contaminants, such as paint, oil, or rust, can be removed with the help of a wire wheel or mounted brush such as the Anchor Knot Wire Cup Brush. Mill scale, on the other hand, may require more aggression from a flap disc or a grinding wheel.
When using a coarse abrasive for faster cleaning results, however, it’s crucial to avoid gouging the surface or removing too much material.

Finishing: Weld Cleaning, Deburring, and Polishing

Weld Cleaning

Abrasive techniques are also employed to do away with post-weld defects and get rid of surface contamination. This includes dealing with weld splatter, slag, excess weld material, and surface oxidation, among others.
An abrasive brush can get rid of most of these contaminants, including spatter and slag. For heavy spatter and slag, use a flap wheel with medium to fine grit. The PFERD Polifan Flap Disc is an excellent choice.

Deburring

Deburring is the process of removing a build-up of burrs and other imperfections from a finished surface. It can reduce waste, improve the quality of a weld, increase the lifespan of a part, and add to its aesthetic appeal.
Abrasive techniques can remove such defects. Flap discs, grinding wheels, and abrasive belts are the most common deburring tools. During this process, it’s crucial to use a finer grit to avoid damaging the part.

Polishing

The final stage of the welding process involves giving the part a smooth finish. If necessary, abrasives may be used to grind down the weld bead to make the joint invisible or prepare the piece for painting.

Grinding wheels are not generally recommended for the polishing phase as they are typically too coarse for fine finishing. Instead, it’s recommended to use a very fine flap disc such as the Maxidisc BriteMax™ Non-Woven. Alternatively, the Bear-Tex Vortex sanding and polishing disc can be effective in preparing a piece for painting.

Join the Grind With nexAir

The role of abrasive techniques in the welding process cannot be understated. No one understands this better than nexAir. For over 80 years, we have helped our customers across the Southeast Forge Forward with the best quality welding supplies and the highest levels of KnowHow. Check out our wide range of abrasive tools to make sure that your next welding project is a success.