Sanding drywall isn’t exactly fun.
But if you do it right, you’ll be rewarded
with a great-looking paint job that will make
all the effort worthwhile. These tips will
help you avoid common drywall sanding
mistakes so you can get the best
results possible from all your hard work.
Use a hand sander ($6), a package of 150-grit drywall
sanding paper that’s precut to fit your sander, and a
sanding sponge for corners and detail sanding. You’ll also
need a double-strap dust mask rated for nuisance dust
and goggles to keep the dust out of your eyes. A hat or
scarf to keep the dust out of your hair is a good idea too.
Sand with light pressure along the edge of seams and
around screws to avoid “fuzzing” the drywall paper.
Sand the center of seams just enough to remove ridges
It’s tempting to buy 80-grit paper to speed up the sanding
job. But because modern lightweight joint compound is
so soft, you don’t need heavy-grit paper to sand it.
Coarse-grit paper or sanding screens will leave undesirable
sanding marks. We recommend precut sheets of 120-grit or
150-grit paper for the best results. Make sure the
paper is taut by first anchoring one end under
the clamp. Then push the other
end under the other clamp with
one hand while you tighten the
clamp screw with the other.
Don’t try to sand out gouges and big ridges. It’s much
easier just to trowel on another coat of joint compound.
This is especially important at the edge of joints,
where too much sanding will damage the paper face
on the drywall. It’s quick and easy to trowel a thin coat
over the edge of the seam to fill a depression.
Touch up grooves and large ridges with another coat of joint
compound rather than trying to sand them out. It may take a few
coats to fill deep grooves.
Do a once-over with your hand sander, making sure
to hit every surface with joint compound on it. Keep a
pencil handy to mark problem areas that need filling or
detail sanding. Then get a handheld lamp and go back
over the job while shining the light parallel to the wall
surface. Use your hand sander and sponge sander to
touch up trouble spots. Mark depressions and other spots
that need filling. Finish the job by filling the marked areas
with joint compound and finally sanding these spots
when they dry.
Sanding after priming is a critical step that most beginners
skip. But sanding at this stage removes paper fuzz
and lumps that will show through your paint job. This is
also the time to take care of other imperfections by filling
them with joint compound. Don’t forget to sand and
reprime these touched-up areas or they’ll also show
up when you paint the walls. Prime the walls and sand them
lightly after the primer dries to remove paper fuzz and lumps.
Sanding inside corners with a hand sander is asking for
trouble. In the first place, it’s difficult to get a crisp corner.
But even more troublesome is the tendency to scuff or
gouge the opposite side of the corner with the edge of the
sander. It’s OK to sand within a few inches of the corner
with your hand sander. Then go back and touch up with a
sanding sponge or folded piece of drywall sanding paper.
With a hand sander, it’s easy to get too close
and gouge the corner. If that happens, touch it up and try again, with a sponge this time.
Even though using a hand sander is straightforward, the drywall
pro we talked to offered these helpful tips. Use moderate
to light pressure and avoid sanding over the same spot in a
straight line. This can leave a groove or depression that will
show up when you paint. Instead, move the sander around
on the joint as you sand. If you do sand too much in one
spot, touch it up with joint compound
and resand when it dries.
Keep the sander angled slightly.
Press lightly and avoid scrubbing
back and forth in one spot.
Don’t sand over electrical
boxes or other openings.
The edges of the box can
rip your sandpaper, or a
piece of the paper facing
on the drywall can roll up
under the sander and tear
off. Keep a few inches
away from electrical box
openings and touch up
around them later with a sanding sponge.
To limit the dust, consider wet-sanding the joints.
Tape with care so you don’t have to do much sanding.
Then buy a big flat drywall sponge ($2 at home centers),
wet and wring it out, and simply wipe smooth any minor flaws.
You probably won’t have to use the coarse side of the sponge
unless you have unusually rough areas.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.
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