Once your joint compound is fully dry, it’s time to sand.
Use sandpaper that is 80 or 100 grit to smooth out any roughness. Alternatively, you can use a medium grit sanding sponge or a 100 grit sanding screen. When sanding, use even strokes and avoid pressing too hard. If you’re using sandpaper, use a drywall sander for support.
As you sand, move from coarse grit sandpaper to a finer grit. While you may start by smoothing out rough drywall mud with 80-120 grit sandpaper, you’ll need to move to 150 grit and then use a finer 220 grit sandpaper for a smooth finish.
Here’s what else you should know.
What is the Best Sandpaper for Drywall?
If your drywall mud is very rough and has a lot of ridges, you need to start with coarse-grit sandpaper to even it out. This will be 80 – 120 grit, depending on how rough the joint compound is. (The rougher the mud job, the lower the grit you need to go.)
After smoothing everything out, finish the drywall by going over it with 150 grit sandpaper to blend the joints and then 220 grit sandpaper to create a smooth surface.
Why You Need the Correct Grit Sandpaper
When finishing drywall joints, using the correct grit sandpaper or sanding block is very important. This is because your initial coats of drywall mud will probably be rough and full of ridges. Using coarse sandpaper helps knock down the ridges and evens everything out.
Drywall mud needs to be completely dry before you sand it. This generally takes about 24 hours. If you try wet sanding the drywall mud before it’s fully dry, it will damage or come off the wall, and you’ll need to reapply it.
Drywall Sanding Tips
Sanding drywall isn’t hard, but there are some steps you can take to ensure a professional-looking finish.
Start with coarse paper and work your way up to finer sandpaper. In the beginning, the coarse sandpaper will help even out your drywall mud. But you can’t stop there. You need to use finer grit sandpaper to finish the drywall and create a smooth surface.
Use a sanding screen if your paper keeps getting clogged with dust. Sanding screens are a great alternative to regular sandpaper. They work the same only they allow sanding dust to pass through and therefore don’t get clogged.
Don’t over-sand the drywall. The point of sanding is to create a seamless finish. If you over-sand, the joint compound will crack, or the edges of the drywall will show through.
Use light, even strokes. If you press too hard or go over the same spot too many times, you’ll create a groove that will be noticeable even after painting your wall.
Use a pole sander for ceilings and hard-to-reach areas. If you’re drywalling the ceiling, your best bet is to use a pole sander. Pole sanders allow you to quickly (and comfortably) reach high places. This is not to be confused for an orbital sander.
Be careful with a hand sander. If you’re using a hand sander on your drywall, don’t press too hard and keep your strokes even. It’s very easy to over-sand and create divots with a hand sander.
If this is your first time sanding drywall, don’t rush it. After the joint compound has completely dried, knock down rough edges with coarse sandpaper. Then blend the drywall mud into the wall and create a seamless finish with fine-grit sandpaper.