Choosing the Right Grits for Your Wood Floor Sanding Project
When you have a wood floor sanding project in line, one of the most important aspects is choosing the right grits in the right sequence to ensure a flawless surface once the project is finished. Despite the fact it is not rocket science, choosing the right grit sequence is not necessarily the easiest thing in the world and it is almost always strictly individually from floor to floor, depending on the current condition of the floor.
However, no matter the specifics of the floor, it is a rule of thumb that you always start with more abrasive grit and then continue with finer ones to the finest grit that finishes the floor to perfection. The first grit should always be the most abrasive one you would use throughout the project, because it is meant to take off the top layer of the floor, which is usually the most worn one and where the one with surface imperfections such as scratches, stains, etc. Next, you would like to smooth out the surface of the floor after the first and most abrasive grit with a finer grit.
The final and finest grit is meant to smooth out all the remaining marks from the previous rounds with the sanding machine and ensure the required finishing touches for a flawless and uniform surface of the floor. Choosing the right grit sequence is essential, otherwise, you won't be able to create the smooth and flawless surface you are going for and a smooth transition between the rounds with the different grits. Picking the right grit sequence will ensure a smooth transition between the grits and no marks left by the sanding machine, while you will be able to achieve an even and beautiful look of the floor's surface and even coverage with the finish.
Usually, you would like to use at least three different grits to achieve the best results, sometimes even more. Choosing the right grit sequence is affected by many factors, the most important of them being the wood species you are dealing with, the age of the wood, the type of the finish, if there is a layer of stain or wood floor paint previously applied, etc.
Different Abrasive Grits
Different brands are offering different sandpaper grits on the market. Choosing a brand is totally up to you. In general, all brands and manufacturers offer pretty much a similar range of sandpaper grits. The grits available on the market are:
12-16-20-24: very coarse
30-36-40: coarse
50-60: medium
80-100: fine
120-150: extra-fine
12 Grit
One of the most abrasive and coarsest grits available on the market. Although not commonly used for beginning the wood floor sanding process, if it comes to a hardwood floor with a heavy adhesive layer on top, for example, if the floor has been under a carpet, or a hardwood floor with several coats of paint or stain, it is recommended to use this grit to remove all the layer of products.
16 Grit
This is the right grit you would like to use when starting a sanding project of the floor with a shellac finish, a single layer of paint, or a floor made out of denser wood species, like maple for example. Starcke offers high-quality sandpaper with a 16 grit made from aluminium oxid - Starcke 10" Sanding Belts, 16G.
20 Grit
The 20 grit is perfect for in-depth removal of an old and worn finish with a lot of surface imperfections. You will be able to remove a lot of wood stock even when sanding denser wood species with this filter.
24 Grit
The 24 grit is suitable for when you work on floors with marks left by a sanding machine such as swirl marks or for when the finish is worn down to the wood's surface on some patches of the floor. The 24 grit is a pretty popular and standard one. It is usually used as a starting grit for floors that have not been sanded for a long time and for floors with a strong and heavy layer of finish. Check out Starcke's offer for a 24 grit sandpaper - Starcke 8" Sanding Belts 24G.
36 Grit
Choose this grit for when you are starting to sand newly installed and unfinished wood floors as this grit are the most suitable for making the floor's surface super smooth and even before you continue with the application of the finish. The aluminium oxide 36 grit by Starcke comes with great quality and it is the ideal solution for time-saving and smooth sanding of hardwood floors.
60 Grit
A standard grit you would like to use mid-sanding. It is not intended to be a grit you start the sanding project with. The 60 grit is usually used right after sanding with one of the previously listed coarser grits. It cannot remove much of the wood and imperfections on the surface, but it is usually preferred for removing swirl marks left by the sanding machine. Starcke does not offer only sandpaper grits suitable for belt sanders. As an example, this 60-grit sanding disc - Starcke 60G Sanding Discs, by the brand is suitable for attachment to other types of sanding equipment. The disc comes with an open coat of excellent surface quality which is heat resistant and impedes clogging.
80 Grit
One more grit that is intended for smoothing out marks left by the more heavy-duty and coarser abrasives you would use in the earlier stages of the sanding process. The 80 grit is usually the last and finest grit many wood floor sanding specialists would use before they continue refinishing the floor. In case the wood floor is a standard one and not in need of more in-depth and thorough sanding, the 80 grit is perfect for finishing up the project. Starcke offers 80 grit in the form of an aluminium oxide sanding belt.
100 Grit
The 100 grit is among the finest ones available and it is used for smoothing out the marks and swirls left by the previous rounds with the sanding machines and after the usage of coarser grits and abrasives. This is usually the finest grit you would use if you have decided to have the floor stained afterwards. Removing all marks left after sanding before continuing with sanding is very important, otherwise, the colour pigments of the stain will highlight these imperfections and enhance them, making them more visible. This is also a great fine grit to use for finishing up a maple, birch, or other denser wood species hardwood floor.