Abrasive and sandpaper buying guide

What are the different types and grains of abrasives?

Abrasives such as sandpaper all fight the same fight, they are most commonly found in sheets or rolls and are used to scour a work surface. The specific use helps to determines the grain size (number of grains) you will need, coarse, medium, and fine grit sandpaper is widely available but it also possible to find extra-coarse or micro-grit sandpaper in very fine, extra-fine, super fine and even ultra-fine.
The number designations used with sandpaper correspond inversely with the coarseness of the grit, the larger the number finer the grain. For shaping or removing material, we opt for 80 or below. Beyond 400, you can easily smooth and polish even the most delicate materials and finishes.

Type of abrasive

There are 3 main types of abrasive and we present them to you.

Corundum paper

Crystallized alumina oxide is used to sand hardwoods and remove old paint. It should have no trouble removing paints, varnishes, and other finishes.
There is also synthetic corundum which are more resistant and designed for the hard-working sanding.

Emery cloth

Mixtures of minerals fixed on canvas for the sanding and polishing of metals. Emery cloth is good against rust in particular. Suitable for intensive use.

Flint

Flint and other materials such as crushed glass are difficult to find and have been largely replaced by other materials. If you happen to come across it, it will still be called "sandpaper" and is ideal for sanding varnishes, softwoods, or plaster.

Mounting Type

The abrasive grains are bonded to different substrates. We’ll explain.

Nylon fiber

It can be found on the self-gripping sheets for sanding blocks .

Canvas

The abrasive cloth is ideal for corners and reliefs because it is more resistant to bending and shaping.

Paper

The firmer the paper is the faster the sanding will go. However, paper that is too thick or rigid can crack while paper that is too thin tears and is less effective. It is used dry on new wood for easy sanding or to remove the paint from the holds of boats or wet to roughen the paint on the cars.

Work by hand or with a sanding block?

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Sanding by hand requires patience and good technique, it can be practiced on flat or irregular surfaces
The sheet of abrasive paper is not always easy to keep in hand. Think of folding it in thirds or quarters to give you something to hold on to and simply switch to a new section as each begins to wear.
For better precision and long-term use, purchase a sanding block. These are blocks of wood, cork, foam, rubber, or synthetic material to which you can secure the sandpaper. They offer an easier grip and better leverage but should only be used on flat surfaces as irregular surfaces will begin to wear the surface of the block. If this happens, a good old sheet of abrasive paper will save you.
Depending on how often and how much you will be sanding, you should consider wearing  protective eyewear or masks.

How to properly use abrasive or sandpaper

1. Use gloves to protect your hands.
2. Sand the wood in the direction of the grain to avoid unsightly scratches.
3. Start with the lowest grit and progress through your various grits until you finish with a finest grit.
4. Remove the dust with a vacuum cleaner for dry sanding with a sponge for sanding with water .

Today, auto-body sandpaper can also be used in dry sanding.