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Are you doing some renovation, replacing old drywall and repainting, and you’re wondering what grit of sandpaper should be used for drywall? Wonder no more, for we’ve researched this question, and we have the answer for you right here.
A 120- to 150-grit sandpaper is best used for drywall. Do not use anything below 100-grit because it is too coarse and can potentially damage the drywall.
We have a detailed section below about how to properly sand your drywall and prepare it for painting. It is important to sand your drywall properly because imperfect sanding will show in the final paint. Read on!
How to sand drywall?
This section assumes that you’ve completed taping and mudding your drywall. It is also important that you wait for the joint compound to dry before moving to the step of sanding the drywall.
Tools and Materials Needed
The items that you will need to prepare before you start to sand are listed below. We included tools that you can use to patch the tape of the drywall, in case you need to.
There will be moments when you find imperfections on the drywall that cannot be fixed by sanding. That is what taping and mudding tools are for.
- 150-grit sandpaper
- Drywall hand sander
- Mud pan
- 12” wide taping blade
- Dust mask
- Goggles or glasses
- Step ladder
- Shop vacuum
- Sanding pole
- Plastic sheets
- Painter’s tape
- Sanding sponges
- Window box fan
- Floor lamp
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The initial preparation focuses on isolating the room where you will work to keep the dust from sanding from getting to the rest of the house. It will also make the work area safer for you while sanding.
Dust from sanding is a fine powder similar to flour, and it is a health hazard. It is very light, and it can easily ride the air current in your house to get to other parts of your house that you wouldn’t expect they’d reach.
Here are the steps to help minimize the amount of sanding dust that will spread throughout the house.
- Seal ducts, vents, doorways, and windows with plastic sheets. Fasten the plastic sheets with painter’s tape. This will help you isolate the room that you will be working on.
- Remove items in the room that you do not need for sanding.
- Remove window screens and mount the window box fan on the window. This will help suck the sanding dust and blow it outside the house.
- Wear proper safety equipment. Keep in mind that you need to replace your dust mask every half hour if you’re working in an under-ventilated area.
- Prepare your favorite music. Music makes any work enjoyable.
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Mapping the Walls and Ceilings
In this section, we will prepare the surface to be sanded by identifying imperfections on the surfaces and marking them.
- Light the floor lamp and point it on the drywall.
- Take your wide taping blade and rest the edge of the taping blade against the wall with the light from the floor lamp on one side. The light from the lamp will show you uneven surfaces under the edge of the taping blade.
- Mark the imperfections on the surface using a pencil. Using a pencil is the best way to mark your drywall. Other writing tools like a felt tip pen can bleed through the paint.
- Mark high areas as “high.”
- Mark low areas with “fill.”
- Fill the low areas with mud and let it dry before sanding. Check the area once more with the lamp and taping blade after drying.
Sanding the drywall
Make sure that you have enough sandpaper before starting to sand the drywall.
The sandpaper will get clogged by the sanding dust as you work on the drywall. Replace the sandpaper regularly so that you will achieve an even finish.
- Sand the lower part of the drywall with a hand sander that is loaded with 150-grit drywall sandpaper. Apply an even push-pull sanding pressure when you are sanding.
- Use the floor lamp to directly light the area that you will be sanding. The light from the floor lamp will highlight the imperfections that you need to sand out.
- Sand the areas that you marked as “high” areas so that they will become level with the surrounding surface.
- Use the sanding pole to reach the upper part of the wall and the ceiling.
- Keep in mind not to sand the inner corners of the walls and ceiling. Using the hand sander and the sanding pole on these areas can cause these tools to slam on the opposite drywall and damage the finish.
- Look for ridges made by dried mud and build-up of mud near the transition edges between the drywalls. These areas should be sanded lightly until they are level with the rest of the surrounding surface.
What to do with protruding screws?
Drive the screw a little deeper into the drywall and then cover the area with mud. Leave it to dry before sanding that area.
How to sand around electrical outlets?
It is best to use handheld sandpaper around these areas. Handheld sandpaper gives you more control of the sandpaper, and this will allow you to be more precise in applying pressure and the direction of your sanding.
Use light and even sanding motion around electrical outlets. Keep an eye out for tape that will get exposed during sanding. Apply additional mud on exposed tape and leave them to dry before sanding once more.
How to sand at the edge of walls and ceilings?
Use a sanding sponge with an angled edge to sand the edges of walls and ceilings. An edged sanding sponge will allow you to sand the inside corners of the drywall without damaging the opposite drywall.
Additionally, a sanding sponge will help prevent your hand sander from cutting into the opposite drywall. In case this happens, you will need to apply mud on the scratches and leave it to dry before you can continue sanding the area once more.
Firmly grip one side of the sanding sponge and apply even pressure as you move it up and down the inner edge. Use a circular motion to smoothen the transition edge of the corner seams.
What is the difference between wet sanding and dry sanding?
Wet sanding requires the addition of water to serve as a lubricant that will reduce the overall friction generated by sanding. This creates a smoother finish.
Dry sanding, on the other hand, is better used for removing more material to level an uneven surface.
What are the advantages and disadvantages of wet sanding?
Its biggest advantage of wet sanding is that it can produce a really smooth finish compared to dry sanding. However, wet sanding is a slow process because it removes less material per stroke compared to dry sanding. On the plus side, it reduces the mess made by the sanding process because of water.
You will need to use a sanding sponge dipped into a pail of water for wet sanding. A sanding sponge has two surfaces—a fine grit side and a medium grit side.
A sanding sponge cannot be attached to any sanding tool like a hand sander or a sanding pole. Thus, wet sanding is done completely by hand.
What are the advantages and disadvantages of dry sanding?
Dry sanding removes more material per stroke, making sanding projects faster to finish. Additionally, you do not need to use a lubricant for dry sanding.
Unfortunately, dry sanding makes a lot of sanding dust that can fly to different areas of the house. Dry sanding is done with sandpaper. Sandpaper can be used with a hand sander or sanding poles.
Can I sand drywall with an electric sander?
An electric orbital sander can smooth out your drywall faster.
Most professionals use an orbital sander to complete most of the heavy sanding, and then they move to hand sanding as a finishing to the sanding project.
Keep in mind that using an orbital sander on your drywall can easily damage the surface instead of helping you complete the work faster. Use an orbital sander with caution and use a finer grit. This will reduce the amount of material that it can remove and will help give you more control over the rate of removal that it will do on your drywall.
A 120- to 150-grit sandpaper is ideal to use on your drywall. If you plan to do some wet sanding, use a sanding sponge on your drywall.
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