USG IMPERIAL Finish Plasters - Manual (Page 2)

Tools Joint Preparation – Joint Tape
– Spring Driven Hand Stapler, 3/8
Љ Staples (if tape is not self-adhesive)
– Steel Finishing Knife
– Trowel
Mixing – Heavy Duty Drill with no-load rating of 900 to 1,000 rpm. Drills with sufficient power include Black & Decker
Model #1322; and Milwaukee Models #1250-1, #1630-1, #1670-1 and #1675-1.
– Cage-Type Mixing Paddle
– Metal Mixing Barrel (16-gal., 1-bag size; 30 gal., 3-bag size; 15-gal. smooth-sided, 1-bag size)
– Buckets/Containers for Water
Plastering – Trowels, Rods, Darbys
– Drop Cloths
– Ladders/Scaffolding
– Trowels
Joint To ensure a smooth, seamless surface, the joints between wall panels must be properly treated to conceal and
Treatment reinforce them before plaster is applied.
For Normal Align I MPERIAL ® Brand Type P (pressure sensitive) Tape over the joint and press it into place over the entire length
Drying Conditions of the joint. Eliminate wrinkles and assure maximum adhesive bond by pressing the entire length of tape with a
steel finishing knife or trowel. Press the tape into corners with a corner tool. Do not overlap.
Alternatively, you can attach I MPERIAL ® Brand Type S Tape with spring-driven hand stapler using 3/8 Љ staples. Use
two staples at each end of the tape; staple the remainder at staggered 24 Љ intervals.At wall-ceiling angles, staple
every 18 Љ to 24Љ along the ceiling edge only. For wall-to-wall interior angles, staple every 18Љ to 24Љ on one edge
only, working from top to bottom. Position the tape to bridge the joint at all interior corners without overlapping. For
fire-rated assemblies, staple either Type P or Type S Tape 8
Љ o.c.
Embed the tape and fill beads with a coat of D IAMOND or I MPERIAL Brand Interior Finish Plaster and allow to set—but
not dry—prior to finish application. Slightly underfill in the bead by screeding along the bead with edge of trowel
after setting the bead. (Best results are obtained by planning the job to permit continuous application of plaster
from angle to angle.)
For Rapid When building temperature-humidity conditions fall in the “rapid drying” area of the graph, or I MPERIAL Brand
Drying Conditions Gypsum Base is being applied over steel studs, or in certain applications to framing spaced 24
Љ o.c., use
S HEETROCK ® Brand Joint Tape embedded with S HEETROCK ® Brand D URABOND ™ Setting-Type Joint Compound or
S HEETROCK ® Brand E ASY S AND ™ Lightweight Setting-Type Joint Compound.
Butter the joints with compound using a trowel or steel finishing knife to force compound into the joints. Center
S
HEETROCK Brand Joint Tape and press it into the fresh compound with a trowel held at a 45° angle. Draw the
trowel along the joint with sufficient pressure to remove excess compound, ensuring the tape is wetted and
covered with a thin skim coat of the excess compound to edge wrinkling or curling. Wipe clean. Allow the joint
treatment to set; then apply a separate coat of joint compound to completely cover the tape, using a 10
Љ or 12Љ
knife or trowel, feathering it 2 Љ to 3Љ beyond the edges of the tape.Allow it to set and dry before plastering.
Joint areas prepared in this manner should be surface dampened with a light application of water by brush, felt
or sprayer just prior to the plaster application to ensure proper absorption. Failure to do this can cause excessive
initial absorption, while completely wet joints will not allow required absorption.
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