Crane Composites CLEANROOM WALL SYSTEM - Manual (Page 7)

Panel and Seam Sealant Sequence
All panels are installed prior to the seam treatment. Before caulk and sealant can be applied,
installed panels need to be adhered for at least 6 hours.
Panel Installation Finish
• Use a laminate roller to ensure all air pockets are removed between the panel and the
wall and to ensure a good bond between the panel and the wall. Start in the top corner of
the panel away from the leading edge. Begin rolling down and out towards the panel edge
without a molding.
(Figure 5)
• Adhesive residue may make panels appear stained and will collect dirt. Remove any
adhesive residue upon completion of the job. To remove latex-based adhesive, clean
with a non-abrasive cotton cloth and warm water. If necessary, use a mild, non-abrasive
detergent. For best results, change water and cleaning rags frequently. For
clean-up with solvent based adhesives, use mineral spirits or acetone to remove residue.
Seam Sealant Application
Wall Preparation
1. Surfaces should be free of grease, dirt, and other contaminants. Clean seams as necessary with
a dry, lint free rag or a rag dampened with solvent if necessary.
2. Installed panels need to be adhered to the wall for at least 6 hours before beginning seams.
3. Remove any adhesive between the panels with a sharp edged screwdriver or small fl at blade
(Figure 12) .
4. Prior to dispensing urethane sealant, each seam will need to receive painter’s tape on each side
of the seam. Tape needs to be applied as close to the panel edge a possible with out going over
into the seam. If panel has a pre-applied tack fi lm, that can be left in place
(Figure 16) .
Preparation of a New Cartridge
1. Loading the cartridge into the dispensing gun
A. Remove the plastic nut from the outlet end of the sealant cartridge.
B. Remove the metal retaining clip and the plastic plug in the outlet ports of the cartridge
and discard (re-insertion of the plugs into the wrong side can cause sealant to cure and
block the ports).
C. Load cartridge into dispensing gun ensuring that the plungers are lined up properly.
2. Leveling the plungers (Figure 13)
A. To ensure that the sealant is mixed and dispensed at the proper ratio, the plungers need
to be level at the start of each new cartridge prior to use.
B. Prior to installing the mixing tip, slowly advance the plungers until a small amount of
material is equally dispensed from each port. Once this occurs, the plungers are level.
C. Hand mix the dispensed material and discard.
3. Attach Mixing Tip and Purge (Figure 14)
A. After leveling the plungers, fi t the plastic mixing tip onto the outlet end of the cartridge and
secure with the plastic nut that was removed previously.
B. After mixing tip has been secured, dispense a small bead of material (approximately one
tip length) to ensure that a proper mix ratio is being achieved.
C. Material is now ready for use.
4. Open Time
A. Open time is the amount of time from when the sealant begins to travel down the mixing
tip until dispensed product needs to be completely worked/processed in the seam.
B. It is important to note that open time begins at initial mix, not at time of dispense onto the
surface of the application.
C. For urethane sealant, the approximate open time is 3-5 minutes at 75°F (24°C). This
means that at an ambient temperature of 75°F (24°C), the material applied to the seams
of the wall panel must be worked/processed within 3 minutes of the initial purge through
the mixing tip.
D. Open time will fl uctuate as temperature increases or decreases. It can be estimated that
for every 18°F (10°C) increase in temperature, the open time will be cut in half.
E. Operators will also need to be aware of the timing in regards to the material remaining in the mixing tip after each application.
Material will either need to be purged (approximately every 2-3 minutes at 75°F) between uses or a new mixing tip applied at
the re-start of a partial cartridge. Temperature fl uctuations described above have same effect on purge time.
Figure 5
Figure 13: Leveling the Plungers
Figure 14: Attach Static Mixing Tip
Figure 16: Applying the painter tape
Figure 12: Remove excess adhesive
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