Sandpaper Grit - When to Use
Sandpaper is an essential part of DIY, however, sometimes it is hard to understand when to use what grit. I hope I can clarify this and help you guys out.
What does the grit number even mean on sandpaper?
Grit is the little bumps on the sandpaper. The number is the amount of grit in a square inch on the sandpaper. So the lower the number the rougher the sandpaper, the higher the number the finer the sandpaper.
When do you use what grit?
Sometimes it is hard to know when to use what grit on what. What I have learned is the rougher the wood or surface you want to make smooth the lower grit you use first. You then work up from there. The lower the grit will get the rough surface smooth but leave scratches from the sandpaper. You will then work up from there and use a higher grit to get the lower grit scratches off.
If you need to, you can use multiple sandpaper to get your surface smooth. By the time you get to the higher grit sandpapers it should be smooth.
If you got a piece of wood to finish I would start off with 100 – 150 grit. The lower number of grit might leave scratch marks you can’t get out, I have done that a many of times. If you do need to go to a lower number of grit you can always go there, but you can’t go back.
The higher grit (300-400) is used for in between coats of paint or finish to make sure your surface is smooth for the next coat.