- Aluminium oxide is the most popular sandpaper for woodworking and it also works well on metal and cured finishes. This type of sandpaper is more commonly used due to it durability – you can use it a lot on hard surfaced materials.
- Garnet is another type of sandpaper and that is most commonly used on bare wood. Garnet does wear down more quickly however it is cheaper than other types of sandpaper.
- Silicon carbide is the sandpaper that is more commonly used for smoothing metals, plastics and joint compounds; this type of sandpaper is not ideal for wood projects however it is used to sand between coats of paint or finishes.
- Ceramic sandpaper is usually the sandpaper is extremely durable and one of the more harder sandpapers. It is generally used as belt or power sanders; however it can be used on wood as well.
Once you have chosen the sandpaper material you need to think about which grade you are going to use. Do you want your sandpaper coarse, medium or fine?
- Coarse-grade sandpaper has grit of 40 to 60 – this is used to scratch away larger imperfections
- Medium-grade has grit of 80 to 120
- Fine-grade has grit 150-180 – this is used in the last stages of detail
You then need to decide whether or not you want to choose closed-coated sandpaper or open-coated sandpaper. Closed-coated sandpaper is used on soft woods and open-coated sandpaper is more commonly used on metals and hardwoods.
The most effective way of getting a clean finish is to sand in only one direction, if you are sanding a piece of wood you should sand along the grain - never against it, otherwise you will end up getting scratches on your project which may be impossible to remove. You can also get a problem of unevenness which will be magnified by the fact that you haven’t sanded with the grain. It is useful to use a sanding block when working on flat pieces of wood so that you can get a better grip, therefore improving the outcome of your project.
If you are planning on putting a dark finish onto your final project it is important not to over-sand, especially if you are using an extra-fine sandpaper. This is because extra-fine paper can cause the wood’s pores to close therefore making it harder to stain.