53-21-00
 ALL  ú ú B02.1 Page 404 ú Jul 12/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 737-300/400/500MAINTENANCE MANUAL
 S 434-010-B00
 (8)  Install the BMS 5-95 or BMS 5-142 sealant (AMM 51-31-00/201).
 (a)  
Apply sealant in the gap between the floor panel and the crease beam in the area that follows (Ref DWG 65-46901): 1) 737-300 AIRPLANES;

 From station 344.00 to station 380.00.
 2) 737-400/-500 AIRPLANES;
 From station 344.00 to station 420.00.

 (b)  
Apply the sealant to the rest of the areas.

 (c)  
Install the water barrier if it is applicable
 (AMM 53-21-11/801).

 S 394-016-B00
 (9)  If you use Flexane 80, do the following steps.
 (a)  If you apply Flexane 80, put the nylon cord around the edges of the panel.
 S 394-017-B00
 (10) Apply the masking tape to the surface of the panel 0.50 inches away from each side of the joint.
 S 394-013-B00
 CAUTION: DO NOT CAUSE A BLOCKAGE WHEN YOU APPLY THE SEALANT NEAR OR
_______ AROUND THE FUSELAGE DRAIN HOLES, OR PATHS. THE FUNCTION OF THE DRAIN HOLES IS TO DRAIN CONDENSATION AND FLUIDS OVERBOARD. IF YOU CAUSE A BLOCKAGE, FLUIDS WILL COLLECT IN THE AIRPLANE. THE FLUIDS CAN CAUSE CORROSION TO THE STRUCTURE, OR A FIRE IF THE FLUIDS ARE FLAMMABLE.
 (11) Apply the Flexane 80 with a flow gun or spatula.
 (a)  
Make sure there are no air bubbles when you apply the sealant.

 (b)  
Use a spatula to make the seal smooth with the masking tape.

 (c)  
Remove the masking tape after the seal is smooth or let the masking tape stay during the curing time.

 S 394-019-B00
 (12) Make the edges of the seal smooth.
 (a)  
Remove all of the unwanted compound with a wooden or plastic tool.

 (b)  
Apply Flexane 80 to the countersunk part of the boltheads on the panel hole to the level with the surface of the panel.

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 53-21-00
 ALL  ú ú B01 Page 405 ú Mar 12/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
 PASSENGER CABIN FLOORS IN WET AREAS - APPROVED REPAIRS
______________________________________________________
 TASK 53-21-00-308-007-B00
 1.  Polyurethane Water Barrier__________________________
 A. General
 (1)  The floor panels in the passenger cabin and the control cabin are installed with an edge tape. The tape will not permit the liquids to go between the cabin and the lower compartments.
 B. Consumable Materials
 (1)  
G01289 Polyurethane Tape - PATCO 809U, 0.009 inch thick

 (2)  
G02304 Tape - Moisture Barrier BMS8-346

 (3)  
G02423 - Polyurethane Tape - 3M 8663DL, 0.018 inch thick, 36 inches wide

 (4)  
G02423 - Polyurethane Tape - 3M 8663DL, 0.018 inch thick, 4 inches wide

 C. References
 (1)  51-31-00, Seals and Sealing
 D. Access
 (1)  Location Zone
 100 Upper Half of Fuselage

 E. Procedure
 S 438-002-B00
 (1)  
If the tape shows deterioration or damage because of the floor panel removal, install new tape. Prior to applying the polyurethane tape, BNS5-142 sealant is applied between the floor panels in the wet areas (Ref 51-31-00/201 Seals and Sealing).

 S 438-004-B00

 (2)  
Install the moisture barrier in the wet areas of the floor structure as follows:

 NOTE: Some operators have reported moisture retention by rubatex
____ tape. Boeing recommends that operators remove rubatex tape if moisture is found. Installation of rubatex tape was intended to reduce passenger cabin noise levels. Appreciable increases in passenger cabin noise levels have not been reported by operators who have removed rubate tape. Use Skyflex tape in place of the rubatex tape.
 (a)  
Center pieces of four inch wide 0.009 inch thick PATCO 809U polyurethane tape or BMS8-346, centered over all floor panel joints in the wet areas.

 (b)  
Apply 36 inch wide 3M 0.018 inch thick 8663DL polyurethane tape over the entire wet area.