Replacement of Fan Blade Coating (Local Repair of the Platform Wear-Strips with Polyurethane Paste) [CFML]

TASK 72-21-20-300-801-A
Replacement of Fan Blade Coating (Local Repair of the Platform Wear-Strips with Polyurethane Paste)

WARNING: REFER TO THE PRODUCT LABEL AND THE MANUFACTURER'S (MATERIAL) SAFETY DATA SHEET (SDS) FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND CORRECT USE OF CONSUMABLE PRODUCTS.

WARNING: WHEN YOU DO WORK WITH COMPOSITE MATERIALS, USE PERSONAL PROTECTION EQUIPMENT AND A LOCAL MECHANICAL EXHAUST VENTILATION OR AN APPROVED RESPIRATOR. YOU MUST NOT BREATHE THE PARTICLES FROM THE REPAIR OF COMPOSITE MATERIALS OR LET THE PARTICLES TOUCH YOU. THE PARTICLES CAN CAUSE INJURY OR IRRITATION TO YOU, AND DAMAGE TO EQUIPMENT.

ZONE: 400

1. Reason for the Job
This procedure gives instructions to repair the platform wear-strip area of the fan blade on the concave (pressure) side with polyurethane paste scotch-weld repair paste 2110 (Material No. CP2946) or to repair the polyurethane paste scotch-weld repair paste 2110 (Material No. CP2946) area on the concave (pressure) side.

NOTE: This repair is applicable on removed fan blade only.

NOTE: You can use equivalent alternatives for standard tools and equipment.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	SPATULA - NON METALLIC

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP1041)	isopropyl alcohol
(Material No.CP2279)	scotch brite type S CFS
(Material No.CP2348)	vac pack 3760 P1
(Material No.CP2929)	airtech flashbreaker
(Material No.CP2946)	scotch-weld repair paste 2110
(Material No.CP2967)	teflease MG2
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS

D. Referenced Information

REFERENCE	DESIGNATION
TASK 72-21-20-000-801-A	Removal of the Fan Blades
TASK 72-21-20-210-802-A	Visual Inspection of the Fan Blade
TASK 72-21-20-400-801-A	Installation of the Fan Blades
Fan Blade - Platform Wear-Strip Area on Concave Side
Fan Blade with all the Platform Wear-Strips on the Concave Side
Fan Blade with Polyurethane Paste and the Platform Wear-Strips on the Concave Side

3. Job Set-up
Subtask 72-21-20-941-061-A

A. Removal of the Fan Blade
(1) Remove the fan blade that must be repaired (Ref. AMM TASK 72-21-20-000-801).

4. Procedure
Subtask 72-21-20-220-052-A

A. Do a visual and dimensional inspection of the platform wear-strip on the concave side of the fan blade as follows:

Fan Blade - Platform Wear-Strip Area on Concave Side

(1) The wear strip worn dimension DIM. A is a minimum of 7 mm (0.276 in.) and a maximum of 8 mm (0.315 in.).
(2) Wear on the composite DIM. B is a maximum of 0.4 mm (0.016 in.).
(3) If your aircraft is in the configuration shown in

Fan Blade with all the Platform Wear-Strips on the Concave Side

apply the repair procedure from Para. 4.B to Para. 4.J.

NOTE: If the platform wear-strip is worn more than DIM. A, it is not possible to repair the fan blade with this procedure. Install the new fan blade (Ref. AMM TASK 72-21-20-400-801).

NOTE: If the erosion depth of the composite material is more than DIM. B, it is not possible to repair the fan blade with this procedure. Install the new fan blade (Ref. AMM TASK 72-21-20-400-801).

(4) If your aircraft is in the configuration shown in

Fan Blade with Polyurethane Paste and the Platform Wear-Strips on the Concave Side

apply the repair procedure from Para. 4.D to Para. 4.J.

NOTE: If the erosion depth of the composite material is more than DIM. B, it is not possible to repair the fan blade with this procedure.

Subtask 72-21-20-350-056-A

B. Remove the upper platform wear-strip of the fan blade as follows:

Fan Blade with all the Platform Wear-Strips on the Concave Side

WARNING: USE EYE PROTECTION WHEN YOU CUT MATERIAL OR PARTS. THE PARTICLES CAN CAUSE DAMAGE TO YOUR EYES.

WARNING: BE CAREFUL WHEN YOU USE SHARP OR POINTED TOOLS. THESE TOOLS CAN CAUSE AN INJURY TO YOU.

CAUTION: BE CAREFUL NOT TO CUT INTO THE LOWER PLATFORM WEAR-STRIP, THE PAINT AREA OF THE FAN BLADE OR THE METAL LEADING EDGE. IF YOU DO, DAMAGE TO THE FAN BLADE CAN OCCUR.

(1) Apply the mask on the lower platform wear-strip, painted area and the metal leading edge with teflease MG2 (Material No.CP2967) and apply the mask on the first layer of masking with airtech flashbreaker (Material No.CP2929) .
(2) Use a sharp tool to cut the platform wear-strip along LINE A. Do not cut into the composite material.
(a) Make sure that you do not cut the lower platform wear-strip.
(3) Remove the platform wear-strip with a sharp or pointed tool.

NOTE: You can use a metal shim to help the removal of the upper platform wear-strip.

Subtask 72-21-20-220-053-A

C. Prepare the area to repair for visual inspection as follows:

NOTE: This step can be done after the sanding (Para. 4.D).

(1) Remove the teflease MG2 (Material No.CP2967) or airtech flashbreaker (Material No.CP2929) .
(2) Clean the area to repair with a Textile-Lint free Cotton - (Material No.14SBA1) moist with isopropyl alcohol (Material No.CP1041) .
(3) Do a visual inspection of the area to repair. Make sure that:

Fan Blade with all the Platform Wear-Strips on the Concave Side

(a) The lower platform wear-strip is correct (Ref. AMM TASK 72-21-20-210-802).
(b) Wear on composite DIM. B is a maximum of 0.4 mm (0.016 in.).
(c) The worn platform wear-strip in the upper area is fully removed.
(d) There is no remaining wear-strip fiber in the upper area.

Subtask 72-21-20-120-050-A

D. Prepare the area to repair for hand-sanding as follows:

WARNING: DO NOT BREATHE THE PARTICLES WHEN YOU DO THE SANDING. USE PERSONAL PROTECTION EQUIPMENT. USE LOCAL MECHANICAL EXHAUST VENTILATION OR AN APPROVED RESPIRATOR. THE PARTICLES CAN CAUSE INJURY OR IRRITATION TO YOU.

(1) If not already applied, apply mask on the adjacent areas with teflease MG2 (Material No.CP2967) (painted area, metal leading edge area, lower platform wear-strip, metal leading edge adhesive) and apply mask on the first layer of the masking with airtech flashbreaker (Material No.CP2929) .

Fan Blade with all the Platform Wear-Strips on the Concave Side

Fan Blade with Polyurethane Paste and the Platform Wear-Strips on the Concave Side

(a) You cannot apply the mask if you did not do the procedure in Para.4.C.
(2) Do a light hand-sanding with scotch brite type S CFS (Material No.CP2279) (minimum grade P240) to remove all the remaining layers of wear-strip adhesive for the configuration shown in

Fan Blade with all the Platform Wear-Strips on the Concave Side

and to make the surface rough for the configuration shown in

Fan Blade with Polyurethane Paste and the Platform Wear-Strips on the Concave Side

(3) Remove the teflease MG2 (Material No.CP2967) or airtech flashbreaker (Material No.CP2929) .

Subtask 72-21-20-110-055-A

E. Clean the area to repair with a Textile-Lint free Cotton - (Material No.14SBA1) made moist with isopropyl alcohol (Material No.CP1041) .

Subtask 72-21-20-220-054-A

F. Do a visual inspection of the area to repair.
(1) Make sure that the surface roughness is homogeneous.

Subtask 72-21-20-110-056-A

G. Apply mask on the adjacent areas with teflease MG2 (Material No.CP2967) (painted area, metal leading edge area, lower platform wear-strip, metal leading edge adhesive).

Fan Blade with all the Platform Wear-Strips on the Concave Side

Fan Blade with Polyurethane Paste and the Platform Wear-Strips on the Concave Side

CAUTION: DO NOT TOUCH THE CLEANED FAN BLADE SURFACES WITH YOUR BARE HANDS. FINGER OILS CAN CAUSE INCORRECT BONDING.

(1) Clean the area to repair with a Textile-Lint free Cotton - (Material No.14SBA1) made moist with isopropyl alcohol (Material No.CP1041) . Do not touch the cleaned surfaces with your bare hands, if you do, do this step again.

Subtask 72-21-20-380-050-A

H. Application of the scotch-weld repair paste 2110
(1) Prepare the scotch-weld repair paste 2110 (Material No.CP2946) .

CAUTION: DO NOT PUT PU PASTE ON THE METAL LEADING EDGE. THIS CAN CAUSE DAMAGE TO THE METAL LEADING EDGE.

(2) Apply the scotch-weld repair paste 2110 (Material No.CP2946) to the fan blade area to repair as follows:
(a) Install the mixing nozzle on the paste cartridge.
(b) Apply a small quantity of the scotch-weld repair paste 2110 (Material No.CP2946) to the fan blade area to repair.
(c) Make the scotch-weld repair paste 2110 (Material No.CP2946) smooth to make it flush with the lower platform wear-strip and the painted airfoil fan blade as follows:
1 Use the SPATULA - NON METALLIC teflon to make the scotch-weld repair paste 2110 (Material No.CP2946) smooth.

NOTE: You can use equivalent alternatives for standard tools and the equipment.

2 Alternative procedure.
Apply a piece of release film vac pack 3760 P1 (Material No.CP2348) on the top of the scotch-weld repair paste 2110 (Material No.CP2946) . Use a roller on the release film vac pack 3760 P1 (Material No.CP2348) to make the scotch-weld repair paste 2110 (Material No.CP2946) smooth.
3 When the repair is completed, remove and discard the mixing nozzle and replace the cap on the cartrige to avoid the paste dry.
(d) Do not put scotch-weld repair paste 2110 (Material No.CP2946) on the metal leading edge.
(3) Cure the scotch-weld repair paste 2110 (Material No.CP2946) as follows:

WARNING: USE THERMAL GLOVES WHEN YOU MOVE OR TOUCH HOT OR COLD PARTS. HOT OR COLD PARTS CAN CAUSE INJURY.

CAUTION: USE A HEATING DEVICE IF THE RELATIVE HUMIDITY IS MORE THAN 40 PERCENT. A RELATIVE HUMIDITY MORE THAN 40 PERCENT CAN PREVENT FULL CURING OF THE PU PASTE.

CAUTION: IF THE FAN BLADE IS NOT CURED IN A LOW MOISTURE ENVIRONMENT (RELATIVE HUMIDITY LESS THAN 40 PERCENT), APPLY THE RELEASE FILM. THIS IS TO GET A SATISFACTORY CURE.

(a) Alternative procedures available.
Before you cure the scotch-weld repair paste 2110 (Material No.CP2946) at room temperature between 64 deg.F (18 deg.C) and 84 deg.F (29 deg.C) for 24 hours, apply a piece of release film vac pack 3760 P1 (Material No.CP2348) on the top of the scotch-weld repair paste 2110 (Material No.CP2946) and attach the film with tape.
1 Alternative procedure.
Cure the scotch-weld repair paste 2110 (Material No.CP2946) at a temperature range of 131 deg.F (55 deg.C) to 171 deg.F (77 deg.C) for 120 to 150 minutes.
2 Alternative procedure.
Cure the scotch-weld repair paste 2110 (Material No.CP2946) at a temperature range of 171 deg.F (77 deg.C) to 190 deg.F (88 deg.C) for 60 to 90 minutes.
(4) If a release film was applied, remove it and remove the teflease MG2 (Material No.CP2967) or airtech flashbreaker (Material No.CP2929) from the fan blade.
(5) Remove the unwanted scotch-weld repair paste 2110 (Material No.CP2946) .

Subtask 72-21-20-220-055-A

I. Inspection
(1) Do a visual inspection of the repaired area:
(a) Make sure that there is scotch-weld repair paste 2110 (Material No.CP2946) on all the repaired area. If there is no scotch-weld repair paste 2110 (Material No.CP2946) on all the repaired area, do the repair again on the missing scotch-weld repair paste 2110 (Material No.CP2946) area(s).
(b) Make sure that the scotch-weld repair paste 2110 (Material No.CP2946) is flush with the lower platform wear-strip and the painted airfoil fan blade.
(c) Make sure that there are no blisters.
(d) Make sure that there is no contamination of more than 0.10 mm (0.0039 in.) in depth.
(e) scotch-weld repair paste 2110 (Material No.CP2946) on the metal leading edge adhesive is permitted.
(2) Do an inspection of the scotch-weld repair paste 2110 (Material No.CP2946) to make sure that it is cured as follows:
(a) Do an inspection of surface shape memory as follows:
1 Apply force with SPATULA - NON METALLIC teflon to the cured surface to cause a movement.

NOTE: You can use equivalent alternatives for standard tools and the equipment.

2 Remove the SPATULA - NON METALLIC teflon.
3 Make sure that the surface of the scotch-weld repair paste 2110 (Material No.CP2946) keeps the initial shape.
(b) Make sure that the cured surface is dry and not wet.
(c) If the scotch-weld repair paste 2110 (Material No.CP2946) is not cured, remove the non-cured scotch-weld repair paste 2110 (Material No.CP2946) from the repaired area and do the repair again.

5. Close-up
Subtask 72-21-20-942-056-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the repaired fan blade (Ref. AMM TASK 72-21-20-400-801).

[Rev.10 from 2021] 2026.04.01 02:51:44 UTC