When it comes to choosing the right type of sandpaper to use for your next project, your decision will largely depend on the quality of the finished product you want, while also considering the surface material you are working on. Aluminum Oxide and Silicon Carbide are two of the most widely used types of sandpaper in the woodworking and metalworking industries due to their versatility, affordability, and consistent performance.
Here are some tips to help you differentiate between the two materials, as well as how to seamlessly use aluminum oxide and silicon carbide in your next sanding project.
Aluminum Oxide Sandpaper
Whether you are sanding wood or metal, aluminum oxide is the most commonly used sandpaper in the industry because it can perfectly sand a wide range of materials, including bare wood, painted surfaces, and metals. In addition, aluminum oxide is extremely durable. An extremely long shelf life and lower cost give aluminum oxide a leg up over other forms of sandpaper, including silicon carbide.
When sanding harder metals, such as titanium or stainless steel, aluminum oxide will not last as long as ceramic or zirconium oxide. Both of these sanding materials offer better durability and cooler operating temperatures than aluminum oxide when applied to hard metal surfaces. However, ceramic and zirconium oxide are much more expensive than aluminum oxide, and aluminum oxide works well when sanding many other metals, which is why it tends to be a more popular choice for professionals across the industry.
The most common form of aluminum oxide is brown aluminum oxide. Other forms of aluminum oxide include pink and white aluminum oxide, which contrast sharply with brown aluminum oxide. Pink and white aluminum oxides break down faster than brown aluminum oxide, but pink and white produce a better finish, which means that pink and white aluminum oxides are more similar to silicon carbide than brown aluminum oxide. Brown aluminum oxide lasts longer because the particles break down and break down more slowly. This increases the lifespan, but you have to sacrifice some finish, which is acceptable in many cases.
Silicon Carbide Sandpaper
Silicon carbide has sharper and harder particles than aluminum oxide, but it is less durable because it is brittle and has a narrower shape, which wears out faster. Because the particles of silicon carbide are incredibly sharp, they can easily cut glass, plastics, and metals with light pressure. However, hardwoods and metals are more difficult to cut. Whether sanding wood or metal, silicon carbide and aluminum oxide can be used together effectively in the same sanding project, especially in woodworking applications.
The usual rule of thumb for sanding is to start with lower-numbered coarse grits and then move on to higher-numbered grits to add finer touches. For example, on a regular three- or four-head sander, you might start by using an 80-grit belt to cut and calibrate the item you are sanding, focusing on achieving the ideal thickness.
In the sanding process, you never skip more than one grit, so the next grit might be 120. Both the 80 and 120 grits might be aluminum oxide, but the final 180 grit should be silicon carbide, depending on whether your goal is to achieve the best finish and you are less concerned about the life of the belt. This strategy cleverly takes advantage of the durability of aluminum oxide while leveraging the sharpness of silicon carbide to achieve a superior finish. For finishing, nothing beats silicon carbide because it is so forgiving.
