Choose the right tools for your application will help you spend less time on repairs and cleaning. Know the difference between a wire brush, grinding wheel and flap disc!
Following the best practice will extend product life, ensure safety and increase productivity and efficiency!
As outlined in the header, the three common tools categories of tools for surface preparation and cleaning in welding applications are:
- Bonded Abrasives/Grinding Wheels
- Coated Abrasives/Flap Discs/Fibre Disc
- Wire Brushes
Abrasive products and wire brushes differ in their performance and purpose. Abrasive products are designed to remove base material, whereas wire brushes are not. When surface preparation or weld cleaning requires that you remove slag or mill scale, a wire brush is generally recommended. Note, heavy mill scale sometimes can be too much for even the most aggressive wire brush. In these instances, choose an abrasive product. Abrasive products are specifically designed for applications such as stock removal, edge beveling, chamfering, and weld grinding and blending. Conversely, if an application requires that you preserve the base material during surface preparation and weld cleaning, a wire brush is still your best choice. Here’s how these products work.
Bonded Abrasives/Grinding Wheels. A combination of the grain type, grain size, and bonding agents (resins and additive fillers) determines the performance of each. Bonded abrasives are generally more aggressive and remove material faster, requiring a skilled operator who knows how to prevent damage, gouging, and undercutting. Wheels are constructed of abrasive grains, including aluminum oxide, silicon carbide, zirconia alumina, ceramic alumina, and combinations of these grains. A resinoid (organic) bonding agent is mixed with the abrasive grains. Finally, this mix is molded and combined with fiberglass reinforcement layers for durability and strength.
Aluminum oxide (AO) wheels are the most popular and are good for many general-purpose applications. Products made with a combination of ceramic and zirconia alumina cost more, but typically provide a better overall life and material removal. They are a good choice for materials such as armored steel, structural steel, cast iron, and INCONEL® alloys.
Coated Abrasives/Flap Discs. These items are constructed using the same grain types as those found in bonded abrasives. Coated abrasives bond the abrasive grains to a backing cloth, which is most commonly a cotton, polyester, or blended backing rather than the hard grinding wheel found on bonded abrasives. This abrasive cloth can be cut into smaller flaps and layered radially to form a flap disc. It is this layered construction that gives flap discs a much softer, more forgiving feel.
The flaps are designed and positioned to wear away as the grains deplete, exposing new, fresh, and sharp grain underneath. Flap discs are often more comfortable to use and offer the aggressive cutting and grinding action of a grinding wheel; however, they also allow for blending and finishing work, which is important when the material needs to be painted, primed, or powder-coated.
Wire Brushes and Wheels. These are the primary choice for weld cleaning, when it is necessary to remove spatter and other contaminants prior to finish or the next weld pass. Remember, the tips of wire brushes do the work, functioning like tiny hammers hitting and preparing the work surface. Applying the appropriate pressure is critical to power brush performance, as excessive pressure flexes and bends the wires, preventing the tips from working. This can lead to premature wire breakage and dramatically reduce brush life.
Power brushes provide the speed and efficiency necessary to complete cleaning and surface preparation applications quickly and efficiently. When you are removing coating from a surface, such as epoxy, paint, or rubber, coated abrasives have a tendency to load—in other words, the material being removed packs between the grains and builds up—stopping their ability to perform. A power brush’s ability to “self-clean” makes it the best choice for these cleaning applications.
When choosing a power brush, you have several knot styles, wire gauges, and trim length options. By changing one or more of these characteristics, you can fine-tune brush performance for a specific application. For example, stringer bead brushes have narrower knots twisted from base to tip, making them better suited to penetrate tighter spaces like corners, fillets, and root pass welds. Cable-twist brushes are also twisted to the tips but have a wider profile that can quickly cover more surface area for fill passes. Standard twist brushes flare at the end, providing an even wider footprint as well as additional conformability.
Crimped-wire brushes provide less aggression and more conformability, making them a great choice for paint and rust removal and deburring. Crimped-wire brushes also leave a consistent “orange peel” finish, so they are a good choice for surface preparation and paint adhesion.
Wheel brushes are designed to work perpendicular to the work surface and are best-suited to smaller, tighter surface areas. Cup brushes are perfect for covering larger, wider surface areas because of their ability to clean a larger area in a single pass.
Making the Right Choice for Your Application
It is important to consider the base material. Generally speaking, it is important not to cross contaminate the accessories. A carbon steel brush being used to clean carbon steel and mild steel should not be used for stainless steel applications.
Secondly, consider the application finish requirements. Is there a need to remove the base material, or is the material being prepped and cleaned for finish or coating. If heavy removal is required, opt for Coated Abrasives, such as our CECROPS or VEROX Flap Disc, or VSM Fibre Disc. Otherwise, wire brush is perfect for cleaning up rust and paint and not harming the base material.
In terms of material, for Coated Abrasives, the most cost-effective is Aluminium Oxide for general-purpose grinding. We also recommend using Zirconium or Ceramic as it maintains its sharpness, resist heat and self sharpen for more aggressive grinding applications.
Lastly, size does matter! Choosing the right size to meet the sweet spot of material removal rate for your application!
All in all, choosing the right abrasives is of huge important to your application which can result in you saving huge amount of money.
(Courtesy of Rick Hopkins, Weiler Corp, www.thefabricator.com)
Do feel free to consult your Abrasive Specialist to get the right products for your application!
Victory Hardware (S)
681 Race Course Road, #01-291, Singapore 210681
tel: +65 62947588
fax: +65 62970893