What Grit Sandpaper for Wood Before Painting?

December 19, 2022

Sanding wood surface before painting.

Now, let me teach you how to make a basic wood ready for painting. To remove the outer layer of paint on the wood, try using the coarse 80-grit sandpaper. Follow it through with 100, 120, 150, and finer 180- grit paper, respectively. Finishing it up with 220-grit sandpaper is incredible. As you notice, a sandpaper’s grit number determines the coarseness of its grit. For most brands of sandpaper, a smaller grit number means the coarser it is. This is one of the reasons why many people do not consistently follow the aforementioned grit order. No one can blame them for getting impatient. However, such pique can give them a much exasperating result in the future. As a result of impatience in sanding, you’ll see that every little scratch and imperfection on the wood’s surface can pop out as soon as the last coating and finishing are done. 

In every woodwork or project, sanding is indispensable. It is a process of making the material’s surface ready for finishing or painting. To achieve the smoothness you look forward to getting, it is imperative to sand the wood canvass with progressively finer sandpaper grits. Too bristly sandpaper can make the wood surface uneven for finishing and painting. The wrong choice of sandpaper for wood can sand away the minuscule details of the furniture pieces you have at hand. 

Surface Preparation Before Sanding the Painted Wood

There are a few steps in painting preparation. Don’t feel impatient if you find yourself doing all the sanding along the way. The “when” and “how” of sanding largely depends on the kind of wood project that you are currently working on. For example: If you plan to have your home interior painted, you need to sand down the drywall. Also, you might want to remove the dried joint compound and other imperfections you can see on the surfaces before painting. 

Step 1: Identify Types of Paint on Wood

You have to know and identify what types of paint material are used on the wood that you are going to sand. If it is oil-based paint, then you will need to scrap and remove the layer of paint on the wood using a scrapper before sanding. If it is water-based paint, you can wash and remove the outer layer of paint using steel wool and a power washer.

Step 2: Surface Cleaning

The first thing first is surface cleaning. Once the surface is cleaned up, get ready to perform the initial sanding. A coarser sandpaper is perfect for the job. It helps you sand out the debris and deep-seated dirt on the material’s surface. Heat and friction, when both applied to the material, can smoothen the surface immediately. On the other hand, use detergent and water. They can do the job better (in most cases). 

Again, if you are thinking of home painting, make sure to have your home exterior or surfaces power-washed. This must come first on the list. Once the surface has dried up, proceed with the tedious yet highly vital process of sanding. Sand out areas or surfaces that need it the most. This cleaning-and-sanding combo is serious in ensuring the strongest adhesion of paint on the surfaces.

Common Sandpaper Grit Sizes

Sandpapers have varied grit sizes and material components. Grit sizes range from 40 to 400. Sandpaper grit sizes depend on the coarseness of the sandpaper. Furthermore, the sizes are based on the size of the particles that comprise the sandpaper. Sandpapers with a higher grit have smaller or finer particles. On the contrary, sandpapers with a lower grit size are coarser because of the larger particles that make up the material. 

Choosing the sandpaper grit size must be based on the level of surface smoothness that you want to achieve. The such choice must be patterned from what point of the sanding process you are in. Let’s say for example. A coarser sandpaper that has a smaller grit number is highly recommended for initial sandpapering purposes. This enables you to sand off more surface imperfections in a short amount of time. Finer sandpaper, on the other hand, is stereotypically used when you are almost done with the sanding process. Such sandpaper grit size can help you achieve a flawless and smooth finish. 

40 to 80 Grit Sandpapers:

This grit sandpaper size is coarse enough to eliminate stock fast. It can help you perform rough sanding with less struggle. If you plan to sand a swollen edge of the door, this is the best thing to grab on. 

100 to 150 Grit Sandpapers:

Sandpapers that have a grit size like this help you start common woodworks or projects that you can think of with less tedium. It does a splendid job when we speak of getting off old paints and varnish. It can help you complete the most common sanding ongoing projects. 

180 to 220 Grit Sandpapers:

This grit size for sandpaper is finer as compared to the rest of the sandpaper grits I mentioned above. Be amazed by how it removes the scratches and flaws caused by coarser sandpapering on your unfinished woodwork project. You can have it for sanding between two paint coats. 

320 to 400 Grit Sandpapers:

Sandpapers like this have the finest grits or particles. It is designed for sanding metal and light sandpapering in-between coats of paint. 

Things You Should Know About Sandpaper Grit

A lot of people assume that a sandpaper’s grit number determines the grit particles that can be found in every square inch of sandpaper. If you are one of the many who thought so, you’ve got something important to learn. The grit number refers to the “number of holes” that the sandpaper sieving material contains as calculated per square inch. Furthermore, these holes are used when sifting the coarse grains during the manufacturing process. Let’s take 60-grit sandpaper as an example. During manufacturing, the coarse particles of this sandpaper grit were filtered using a 60-hole per square-inch screen. 

What are the Challenges of Sanding?

When it comes to sanding, the most important thing to do is to take away all the noticeable surface imperfections or flaws. This includes all those tiny scrapes and cuts that resulted from preceding sandpapering. See to it that the surface is seamless from all the flaws before advancing to the next level of sanding. In the first place, this is the main purpose of sanding. There should be no trace of irregularity on the surface to see incredible painting results. Others believe that experience can teach us how to sand. Yes, there is truth in it. However, you must know the different methods that can you achieve great results. The first method involves the elimination of the dust on the wood material using looking at its surface through a reflected light at a low angle. You can take advantage of a fixed object on a stand or a window. On the other hand, you can use the second method. Simply drizzle the wood and inspect its surface through reflected light. Try to inspect the sanding results from various angles. 

Sandpapering is a tedious job. For some, it is endless. But less attention spent on sanding can accentuate the imperfections of the material once the final finish or color has been applied unto its poorly-sanded surface. 

A sanding job, to be considered an excellent one, must be flawlessly gleaming like that of the oak floors. Its smoothness must be extraordinary as well. Imagine a seamless painted ceiling or wall. A very shiny varnished tabletop is another display of an outstanding sandpapering job. With a high level of patience and consistency, you can make awesome woodwork or project too. 

How Sanding Helps The Painting Project?

If you want to see a seamlessly smooth and polished finish for your painting project, sanding is a must. I keep on repeating this idea in the earlier part of this post. Now, let me say it again. Sanding prepares the material for painting. Through this process, imperfections on the surface are eliminated. Sanding creates rough small ridges on the material, adding to the paint’s grip. 

It is also essential to choose the right sandpaper grip to utilize. I tell you, doing so creates a big difference to your project (in general). Unfortunately, selecting sandpaper for a sanding job is not a joke. To win over this challenge, get help from these suggestions and bonus tips below.

Recognize sandpapers’ numerical rating based on the size of the grit particles. Sandpapers with a much lower grit size number are those that are coarser. On the contrary, higher grit-numbered sandpapers are the finer ones. 

Bear this tip in mind. The fact that coarse sandpaper can leave bigger and deeper sandpapering traces and scratches on the surface, start your project with such kind and finish it with high-numbered sandpaper grits. Persistently sand off those imperfections and work your way up and around those finer grits. Finer sandpapers can help you complete your woodwork projects with ease and perfection. 

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