Use and Care Guide

20
Conditions
SHRINKAGE PROBLEMS
Shrinkage
Delayed Shrinkage
Misinterpreted
Shrinkage
MISCELLANEOUS PROBLEMS
Pock Marking
Probable Cause
Compound used too thin or
watery. Applied too soon after
mixing. Improper drying between
coats. Painting before joints are
thoroughly dry. Too deep fills in
one coat. Slow drying.
Improper drying conditions.
Painting before compound and
wallboard are thoroughly dry.
Under high humidity, slow drying
conditions, joints and wallboard
may hold moisture for weeks.
Improper wallboard application
including: nails dimpled too deep,
fractured core of wallboard,
fractured face paper, corner bead
applied improperly, tape photo-
graphing.
Entrapment of air in the mixed
compound and in application.
Over-mixing of compound.
Compound mixed too thin. Heavy
fills. Improper application technique.
Compound applied too loosely.
Preventive Action
Use compound at heaviest
workable consistency. Allow to
stand before using. Allow thorough
drying of compound between
coats and prior to painting. Apply
additional coats on deep fills.
Provide proper drying.
Provide proper drying conditions.
Allow complete drying before each
coat of joint treatment and before
repainting.
Less dimple of nails. Press wallboard
snug to nailing member before
dimpling nail. Use Gold Bond
Gypsum Wallboard. Re-nail where
necessary. Use Quick Set com-
pound for at least the first coat on
nails and corner bead. (See tape
photographing.)
Mix compound as quickly as possible
and let stand until binder is in solu-
tion before remixing. Mechanical
mixers should have 500 RPM
maximum. Use heavier mix. Make
additional passes over joints and
bead with hand or mechanical
tools. File trowel edges square
regularly to avoid entrapment in
application. Apply compound
thinly and use more pressure on
finish coat.
Corrective Action
Allow to thoroughly dry and re-coat.
Provide proper drying.
Allow to thoroughly dry and re-coat
affected joints.
Nails: re-nail where necessary. Cut
out any loose areas and fill with
two or more coats of Quick Set or
regular joint compound. Re-coat
corner bead. (See tape photo-
graphing.)
Remove sanding dust that may
collect in “pocks” prior to painting
and refloat joint as necessary. When
condition exists after painting, float
with compound and repaint.