Just about every DIY or craft project requires some kind of sandpaper. But what is sandpaper and how do you know what kind to use for what application? Our friends at Jack’s Paint & Hardware explain.
Not all sandpaper is created equal
Although the most familiar types of sandpaper are probably the individual sheets of paper with which DIY handymen prepare surfaces for painting and crafts such as decoupage, the term “coated abrasives” actually includes a wider selection of products for both commercial and industrial use. Sandpaper is essentially a single layer of rough grit attached to a flexible base material. It can easily be cut down to the size that a project requires. In addition to their commonly found form, sandpapers are also available on belts, rolls, and disks specifically designed to fit orbital sanders, electric handheld vibrating sanders and small handheld belt sanders. The two different grades of sandpaper most commonly found are commercial and industrial.
Commercial-grade sandpaper is the most well-known and is readily found at hardware and craft stores. It generally has a less resilient paper backing than industrial sandpaper. The glue used in commercial sandpapers is also not strong enough to cope with excessive heat or moisture, but readily copes with the demands expected of it.
Industrial-grade sandpaper is usually only obtainable through industrial supply stores. It is designed specifically for the needs of production line work and has a far stronger grit on a more resilient backing material and is bonded with exceptionally strong glue.
Different uses for sandpaper
Sandpaper is widely used in woodworking projects as well as in auto body work and metal finishing. Sandpaper is vital to prepare these surfaces for final finishing. A woodworker uses progressively finer pieces of sandpaper to get a smooth finish on the project he is working on. By systematically going through the “grits” each progressive piece of sandpaper removes the scratches left by the previous piece. Being impatient and skipping grits in order to complete the job in a quicker time is not necessarily a time saving move. More often than not you will simply end up sanding for a longer period just to remove the scratches left by the previous grit.
What do the different colours mean?
Sandpaper comes in a variety of different colours, such as orange, black, grey or green. Some manufacturers use different colours to differentiate between different grit sizes. Since colour variations are not standardised between manufacturers the colours are usually meaningless.
Grit is the term for the abrasive surface on the sandpaper. The sizes of abrasive grains range from fine particles that look like icing sugar to larger particles that look like brown sugar. Finer grains are used for surface finishing, while larger grains are used to shape and remove excess material.
* Remember: the smaller the number on the sandpaper, the larger the grit. Below is a guide of what grit sandpaper is commonly used for what application.
Use for DIY projects that require heavy-duty sanding work.
Use for DIY projects that require you to smooth surfaces and to remove small flaws and imperfections.
Use for DIY projects that require final sanding before finishing.
This grading system can be further broken down into even finer grades of grit if very finely detailed or professional work is being done.
Use for DIY projects where you have to sand between coats of stain or sealer.
Use for DIY projects where you have to remove fine imperfections and surface flaws between finishing coats.
This is the finest grade of paper and should be used in DIY projects where you are required to do a final sanding to remove the smallest of surface imperfections such as fine grains of dust and tiny hairs.
DIY professionals use specialty sandpapers with water to polish metal and sometimes table tops and guitar bodies when heavy coats of acrylic lacquer are built up and a glassy, polished look is required. Wet sandpaper ranges up from 220 to 600 grit. Wet sandpaper is often black in colour and almost smooth because the grit is so small.