(8)  
Between body stations 178 and 277, apply faying surface seal BMS 5-95 between floor webs, straps, and floor structure components. Do not apply seal on removable panels installed with nutplates.

(9)  
Replace damaged tapes

(10)
Treat holes in floor beams with brush alodine and primer (Ref. 51-21-41 CP).

(11)
Apply a layer of grease to the floor beam holes before you install the floor panel fasteners.

(12)
Coat floor panel fasteners with grease and secure panel by installing fasteners. Install and start all screws in panel before tightening.

(13)
Torque floor panel screws as follows:

(a)  
Panels using two-piece insert - 20 to 25 pound-inches.

NOTE:  Recheck torque prior to installing floor covering.

(b)  
Panels using one-piece insert - 30 to 35 pound-inches.

500 
Feb 01/95  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  53-21-0 Page 401 

NOTE:  Allow panel dishing at fastener of -0.005 to + 0.030 inch. No recheck of torque required.
(14) Install seals.
(a)  Do these steps to apply sealant to all edges in the wet areas, along the seat tracks, and between the panels: 1) Apply one layer of masking tape to the edge of the joints that are adjacent to
and along the full length of the seam that you will fill. 2) Refer to the instructions on the container to prepare the Flexane-80 sealant.
NOTE:  The pot life of the Flexane-80 sealant kit is approximately 15 minutes. You must apply the compound before the pot life ends.
3) Fill the lower half of the seam with the Flexane-80 sealant.
4) Fill the upper position of the seam with the Flexane-80 sealant.
5) Remove all unwanted sealant from the seam.
6) Let the sealant dry. Make sure the sealant is smooth and constant. The

recommended dry times are as follows:
Temperature (°F)  Time Range (Hours) 
80° or over 70° - 80°60° - 70° 4 to 6  6 to 8  8 to 10 
7) 8)  Remove the masking tape after the sealant has dried. Replace all the equipment that was removed to get access to the panel. 

500 
53-21-0 Page 402  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  May 01/03 

PASSENGER CABIN FLOORS - APPROVED REPAIRS
1.  Repair Floor Panel Tapes
A.  Equipment and Materials
(1)  
Tape - BMS 8-283A Type 1 (Ref 20-30-51)

(2)  
Tape Mystic #7300 (Ref 20-30-51)

B.  Floor panels in the passenger cabin (and the control cabin) are installed with a peripheral tape to provide a liquid barrier between the cabin and the lower compartments.
C.  If inspection of tape shows deterioration or damage due to floor panel removal, install new tape per Chapter 51, Seals and Sealing.
D.  Replace damaged tapes
500 
Jun 20/84  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  53-21-0 Page 801 

WATER BARRIER - APPROVED REPAIRS
1. General
A.  The water barrier consists of mylar sheets (transparent), vinyl sheets (nontransparent) or 18 inch wide strips of vinyl tape bonded to floor panels. This section describes how to cut the water barrier in order to remove a floor panel and how to repair the water barrier after the floor panel is installed.
B.  Self-adhesive vinyl tape (Ref 20-30-51) applied at right angles to the seat tracks with a 1-inch overlap is the preferred replacement of the water barrier.
C.  Cutting the water barrier is accomplished by locating the edges of the floor panel and cutting through the water barrier around the edges of the floor panel to allow removal of the floor panel. Floor panel fasteners covered by vinyl may be exposed by peeling back the vinyl. Floor panel fasteners covered by mylar may be exposed by cutting away circular patches for each fastener. Remove floor panels per Passenger Cabin Floor - Removal/Installation.
2.  Vinyl Water Barrier Approved Repairs (Tape)
A.  Equipment and Materials
(1)  
Tape - Permacel 306, 10 mil thick by 18 inches wide (Ref 20-30-51)

(2)  
Sealant - Dow Corning 30-079 (Ref 20-30-11)

B.  Repair Vinyl Water Barrier
(1)  
Apply tape at right angles to seat tracks with a one-inch overlap minimum.

(2)  
Edge - seal tape overlap with sealant.

NOTE:  Three-inch wide tape centered over edge of overlap may be used in lieu of edge-seal sealant.
3.  Vinyl Water Barrier Approved Repairs (Sheet)
A.  Equipment and Materials
(1)  
Solvents