(d)
Keep the minimum cure time and temperature at 6 hours and 64°F.
(e)
To apply the cure pressure, do these steps:
1) Apply a smooth constant pressure to the rub strip every 15 minutes during the first 3 hours after your assemble the parts.
2) Keep a continuous bead of the adhesive at the bond line to get a satisfactory bond between the mating surfaces.
3) Apply more pressure to remove the air pockets in the bond line during the first 3 hours after the parts are assembled.
E. Procedure - Repair Bonded Phenolic Rub Pads (field repairs with a heat source available)
S 348-005-B00
(1)
Refer to the steps in the first procedure to apply the adhesive on the mating surface.
S 868-007-B00
(2)
Do these steps to apply a new pad:
(a)
Mix 22 |2 parts (by weight) of BMS 5-26, Pro Seal 890 B-2 with activator, to 100 parts (by weight) of the base component.
(b)
To install the new rub strip on the assembly, do these steps: 1) Make sure the mating surfaces are clean. 2) Put the rub strip against the assembly surface.
NOTE: Do not use a clamp on the rub strip.
____
3) If the clearance between the mating surfaces of the rub strip and the assembly is greater than 0.125 inch, do this step: a) Install a new rub strip with a clean roller to get a
smaller clearance. 4) Apply a thin constant finish of adhesive (approximately 50 grams for each square foot) to each mating surface.
(c)
Assemble the parts in less than 25 minutes after you mix the adhesive.
(d)
To cure the assembly, do these steps:
1) Use two heat lamps, 250 watts each, as a heat source. Put the lamps 9 inches apart and 6 inches from the rub strip. Make sure the heat lamps point down on the rub strip.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
51-51-00
ALL ú ú B01 Page 806 ú Jul 15/96
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 737-300/400/500MAINTENANCE MANUAL
2) Apply heat on the assembly at a temperature of 90 (|5)°F. Permit a minimum of 1-1/2 hours from the time you mix the adhesive to the time when you cure the adhesive.
3) Cure the assembly for 2 hours minimum at 85 to 120°F.
NOTE: Use a thermocouple to measure the temperature.
____
4) Let the assembly stay for 20 minutes (minimum) before you apply the cure pressure.
(e) To apply the cure pressure, do these steps: 1) Apply a smooth constant pressure to the rub strip every 15 minutes during the first 2 hours after you assemble the parts.
2) Keep a continuous bead of the adhesive at the bond line to get a satisfactory bond between the mating surfaces. 3) Apply more pressure to remove the air pockets in the bond line as the adhesive cures in the assembly.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
51-51-00
ALL ú ú B01 Page 807 ú Jul 15/96
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
