Smooth drywall finishing – USG Manufactured Housing Handbook User Manual

Page 17

were not a problem. However, do
not leave any during the applica-
tion of this final coat or they will
mar the finished surface.

26 Third Coat, Outside Corners

and Metal Trim
Allow second coat to dry as com-
pletely as possible. Sand lightly if
necessary.Apply third coat of
S

HEETROCK

MH Brand Lightweight

Setting-Type Joint Compound (T

Lite) with 10

Љ knife,feathering

slightly beyond second coat.

27 Sanding

Allow third coat to dry. Lightly
sand imperfections in finished
joints, corners and over fastener
heads. Carefully remove sanding
dust with damp sponge.

Tip
Use a fine-grit sandpaper in a
tool designed for drywall sanding
so you don’t dig into the joint
compound. For best results, use
#120-grade or finer sandpaper

(#200 grade or finer mesh cloth)
when sanding conventional-
weight all-purpose joint com-
pounds. For topping and light-
weight joint compounds, use
#150-grade or finer sandpaper
(#220-grade or finer mesh cloth).
Avoid roughening the surface
paper when sanding. If you do
roughen it by accident, repair the
damage by applying a little joint
compound with a 6

Љ knife.

Wet Sanding
When only minimal sanding is
needed, try wet sanding with a
sponge. It eliminates dust and
does not scuff the surface paper.
Use a small-celled polyurethane
sponge similar in appearance to
carpet padding. Saturate sponge
and wring to prevent dripping. Rub
joints to remove high spots, using
as few strokes as possible. Clean
the sponge frequently during use.

28 Storage and Cleanup

Before storing unused drying-
type joint compound, clean sides
and lid of container so no dried
compound falls into the mixture.
Level drying-type joint compound
surface with knife and cover con-
tainer tightly. If storing for a long
time, cover surface of joint com-
pound with approximately 1/2

Љ of

clean water and cover container.
Do not store in direct sunlight or
where freezing conditions may
occur. Pour off water before
using stored joint compound.
Clean tools with warm, soapy
water.

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Glitter Effects
Sparkle, particularly under artificial
light, can be added to ceilings for
unusual and interesting effects
with the use of glitter. Glitter comes
in 1/32 to 1/16 in. cuts in silver,
gold, blue, red, fuschia, or green,
and is applied with hand-cranked
or air-powered guns. Application
usually consists of embedding glit-
ter in the freshly applied ceiling
texture while surface is still wet.
Depending on effect desired, fig-
ure 1 lb. of glitter per 500 sq. ft. of
ceiling.
If you have applied texture to your
panels, skip the following instruc-
tions for completing a smooth fin-
ish. Go to step 28 for storage and
cleanup information.

Smooth Drywall Finishing
If you have skipped the Texturing
section because you wish to create a
smooth drywall finish, the steps that
follow will guide you through the
completion of the smooth-finishing
process.

25 Third Coat, Flat Joints and

Fasteners
Allow second coat to dry as com-
pletely as possible. If necessary,
remove imperfections with knife
or sandpaper. Apply a thin finish-
ing coat of S

HEETROCK

MH Brand

Lightweight Setting-Type Joint
Compound (T

-S

Lite) or

HEETROCK

Brand Lightweight

Setting-Type Joint Compound
(E

ASY

AND

) with a 12

Љ knife to the

flat joints and a 6

Љ knife to the

fastener heads. Press knife firmly
so joint compound fills depres-
sions but does not significantly
add to thickness. Feather edges
at least 2

Љ beyond second coat.

Tips
Do not sand unless it is necessary.
If you do sand, use fine-grit sand-
paper on fully dry compound, and
be careful not to scuff the gypsum
panel paper to minimize surface
touch-up requirements.

Before applying the final coat,
check to see if tapered joints are
level with surface. Hold the 10

blade across the joint, straight out
from the wall. If the blade can be
rocked across the joint, the joint is
crowned. It must be hidden by
feathering the final coat out as far
as possible.

Use the “splitting” technique
(described in the section on sec-
ond coats) to make the slope of
the compound from the crown to
the surface of the board as grad-
ual as possible.

When applying earlier coats,
minor depressions and grooves

Smooth Drywall
Finishing

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