Crane Composites CLEANROOM WALL SYSTEM - Manual (Page 10)

Seams Around Doors and window Frames and Other Special Application Areas
1. Repeat process listed in Vertical Flat Panel Seams.
2. Material should be dispensed into each seam at a rate such that the seam is completely
fi lled with sealant but completed within the necessary open time for the sealant. As these
seams typically have a larger gap, they may not be able to be fi lled by the
sealant in one pass. In that situation, an initial “fi ller bead” can be applied and then
a secondary bead can be applied over the top of the initial bead after initial bead
has reached full cure.
A. A
mechanical fi ller, such as weather-strip putty, may also be used to fi ll large gaps
prior to the application of the Urethane Sealant.
B. IMPORTANT NOTE: A larger mass of sealant, which is likely present in these
types of seams, will lower the available open time during which the material can be
successfully smoothed.
3. Smoothing the Sealant
A. After the sealant has been dispensed, smooth the sealant beads fl ush with the panel surface.Since these joints are larger
and often have an irregular shape, it is at the discretion of the installer to determine the best method for smoothing the joint. A
combination of common smoothing tools may be required. (Inline seam fi nisher should be used for small in-line panel seams
or larger radial seam fi nisher used for corners.)
B. Smoothing of the sealant must occur within the open time of the sealant.
C. As soon as the smoothing of the sealant is complete, remove the painters tape. Any excess sealant on panels can be cleaned
using a solvent dampened rag.
Seam Sealant Cleaning
Clean equipment and tools prior to the sealant cure with organic solvents such as isopropyl alcohol.
Figure 24: Typical Window Seam Application
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