Sandpaper – A Buying Guide
Sanding is an obligatory step in many wood and metal works.
The sanding process may even appear multiple times in a project: course graft when removing rust or old paint that to reveals the sins beneath to fine grades at the end of the project, giving the product a soft finish and revealing its true beauty.
To help minimize time and effort involved in manual sanding, palm sanders are a must have in every shop.
Although power comes from these machines, the sanding and, consequently, the results will be a true reflection of the quality sandpaper attached.
Selection is a crucial step. What seems like endless hours of work heavily relies on it.
Thus, in this buying guide we’ll outline the most important aspects to consider next time you need sandpaper.
I’ll begin by outlining the standards used both in the US and Europe.
In the US, CAMI – Coated Abrasive Manufactures Institute, use a scale-based system (low to high numbers) reflecting the coarseness of the sandpaper – low = very coarse (40-grit).
This number rises as the grit is smaller (less coarse)
In Europe the FEPA – Federation of European Producers of Abrasives, use a slightly different scale-based system though the principle is the same.
The letter ‘P’ precedes the grit number on the sandpaper
The list below outlines the corresponding grades between the two standards:
40-grit (CAMI) is approximately (FEPA) P-36 or P-40 – Coarse
80-grit (CAMI) is approximately (FEPA) P-80 or F-100 – Medium Coarse
100-grit (CAMI) is approximately (FEPA) P-100 or P-120 – Medium
120-grit (CAMI) is approximately (FEPA) P-120 or P-150 – Medium
220-grit (CAMI) is approximately (FEPA) P-180 or P-220 – Fine
400-grit (CAMI) is approximately (FEPA) P-600 or P-800 – Very Fine
The first factor we’ve to consider is the grit size, which refers to the amount of abrasive particles per square inch, and, in turn, depends on the size of the particles.
Smaller grit sizes correspond to bigger particles and thus a more coarse paper; conversely, the opposite occurs with higher grit sizes.
We can classify papers according to grit size ranges (or measures of coarseness):
- Coarse/Stripping Sandpaper (40 to 80 grit): These are great for removing paint, rust and stain out of the materials to work with. They also serve in leveling and shaping applications. We recommend you to incorporate them into your palm sander for better results.
- Medium/Prepping Sandpaper (100 to 150 grit): These are used to remove scratches and smooth the working pieces in order to prepare them for finishing. Since this stage of the sanding process is still tough, you can use your palm sander for it.
- Fine/Finishing Sandpaper (180 to 320 grit): These are the used for the last retouches given to the product. The fine sandpapers are used between coats of paint or varnish in order to obtain a smoother result. Since these papers are intended to give last retouches and it can be somehow a delicate process, we don’t encourage you to use your palm sander with these.
You can of course get very high grits of paper depending on the project. I’ve recently used
Type of Sanding Paper
The abrasive material of your paper will determine the type of material you can sand with it. Additionally, the type of sanding paper you choose might, or might not, be compatible with your power sander. Here we review the most common abrasive materials:
- Emery: It is commonly used to remove rust and to polish steel and other metals –it can be too much for wood. This can be used in palm sanders.
- Aluminum Oxide: This works great for most applications, including wood and metalworking. It can also be used for power sanding.
- Ceramic Alumina: This is an extremely hard and tough material which is ideal for power sanders. It can be a bit pricey, but it’s durable and can go along with wood and metals –both in removing undesired materials and reshaping wood.
- Garnet: Garnet sandpapers are excellent for finishing works. This material is not that abrasive and leaves smoother results. We don’t encourage you to use it for palm sanders.
- Zirconium Alumina: This material is suitable for wood, fiberglass, metals and even painted surfaces. Since it’s more durable than aluminum oxide, it’s used a lot in power sanding.
- Silicon Carbide: It is usually used for finishing metals or for “wet sanding”. It is not often used with power sanders.
Next time you are purchasing sandpaper for your palm sander, remember there are 2 important things to bear in mind:
- The grit size of the sandpaper determines the type of application it’s destined for. Coarse to medium sandpapers are ideal for palm sanders, while fine sandpapers are best for manual sanding.
- The abrasive material your sandpaper is made of determines its range of applications and the materials you can sand with it. Emery, Aluminum Oxide, Ceramic Alumina and Zirconium Alumina do better with palm sanders
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