DOC AIRBUS | AMM A320FSPOP 533 - Blending and Buffing of Steel, Nickel, Cobalt, Aluminum and Magnesium Alloy Components [PW11]
TASK 70-28-00-910-802-A
SPOP 533 - Blending and Buffing of Steel, Nickel, Cobalt, Aluminum and Magnesium Alloy Components
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Referenced Information
3. Job Set-up
Subtask 70-28-00-860-051-A ** ON A/C NOT FOR ALL
Subtask 70-28-00-910-051-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 13:02:18 UTC
SPOP 533 - Blending and Buffing of Steel, Nickel, Cobalt, Aluminum and Magnesium Alloy Components
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
WARNING:
MAGNESIUM DUST IS EXTREMELY FLAMMABLE. FOLLOW THE PRECAUTIONS VERY CAREFULLY TO PREVENT FIRE. BE SURE TO FREQUENTLY REMOVE BLEND DUST FROM THE PART, BLENDING AREA, AND GLOVES WORN DURING THE REPAIR.
CAUTION:
LIMITS SPECIFIED IN THIS SECTION ARE FOR GENERAL USE ONLY. LIMITS SPECIFIED IN THE PART-SPECIFIC MANUALS TAKE PRECEDENCE. POST-BLEND SURFACE TREATMENT REQUIREMENTS WILL BE DETAILED WITHIN THE SPECIFIC BLEND REPAIR.
CAUTION:
WHEN YOU DO THIS PROCEDURE, BE SURE TO USE GOOD SHOP PRACTICES AND COMMON SENSE. ABUSIVE BLENDING CAN CAUSE DAMAGE THAT IS HARMFUL TO THE LIFE AND FUNCTION OF THE REPAIRED PART.
CAUTION:
TO CONTROL DUST AND NOISE CAUSED BY BLENDING, AND TO REDUCE THE RISK OF FIRE HAZARD FROM BLENDING DUST OF CERTAIN MATERIALS, WHENEVER POSSIBLE, DO THE BLENDING OPERATION IN A VENTILATED BOOTH. CONTACT YOUR LOCAL ENVIRONMENTAL HEALTH AND SAFETY PERSONNEL FOR SPECIFIC REQUIREMENTS.
CAUTION:
USE ONLY MINIMUM PRESSURE WHEN YOU APPLY BLENDING TOOLS TO PARTS. EXCESSIVE PRESSURE AND SPEED WILL CAUSE SPARKS OR AN ORANGE PEEL EFFECT THAT CAN POSSIBLY BE HARMFUL TO THE PART. KEEP MATERIAL REMOVAL TO A MINIMUM. DO NOT EXCEED BLEND LIMITS.
CAUTION:
CHECK THE PART FREQUENTLY FOR HEAT BUILD-UP. IF THE HEAT BUILD-UP IS TOO HOT TO TOUCH WITH YOUR HAND, GET THE PART TO DECREASE IN TEMPERATURE BEFORE YOU CONTINUE WITH THE REPAIR. OVERHEATING OF PARTS DURING BLENDING CAN CAUSE EMBRITTLEMENT.
CAUTION:
DO NOT OVERHEAT THE PART BECAUSE DAMAGE CAN OCCUR.
CAUTION:
BE SURE TO DRESS THE ABRASIVE TOOL BEFORE BLENDING TO GET THE BEST TOOL PERFORMANCE AND TO PREVENT MATERIAL CROSS-CONTAMINATION.
CAUTION:
USE A SHIELD OR MASKING TO PROTECT OTHER SURFACES FROM DAMAGE BY ACCIDENTAL TOOL CONTACT DURING THE REPAIR.
NOTE: Always obey the specific procedures and limits in the maintenance manual maintenance task.
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | BORESCOPE - BLENDING |
| No specific | 1 | POWER TOOL |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.P05-058) | Brush |
| (Material No.P05-066) | Buffing Polishing Compound |
| (Material No.P05-353) | Cloth Wheel (Non-coated) |
| (Material No.P05-354) | Polishing Compound |
| (Material No.P05-384) | Silicon Carbide Deburring Compound |
| (Material No.P05-421) | Scrub Pad |
| (Material No.P05-422) | pad, scrub |
| (Material No.P05-426) | Polishing Compound |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 70-25-00-910-801-A | SPOP 70 - Fluorescent Penetrant Inspection (FPI) - Local Application |
| TASK 70-28-00-910-803-A | SPOP 42 - Chromate Conversion Coating of Aluminum |
Subtask 70-28-00-860-051-A ** ON A/C NOT FOR ALL
A. Not Applicable
4. ProcedureSubtask 70-28-00-910-051-A ** ON A/C NOT FOR ALL
A. Blending and Buffing of Steel, Nickel, Cobalt, Aluminum and Magnesium Alloy Components
(1) General
(a) Blending is an operation that is used to remove nicks, scratches, high metal and other surface irregularities by intentional removal of base metal. Manual or mechanical methods are used to make shallow and smooth surface depressions that reduce the stress concentration from the damaged area by the distribution of the stress concentration over larger, more tolerant areas.
(b) Before you start any blend repair, make sure that the part is crack-free (Ref. AMM TASK 70-25-00-910-801).
(c) Non-toleranced enclosed areas defined in blend repairs are to corners, points of tangency between surfaces or at points opposite one of these locations. Enclosed areas will assume a tolerance of plus 0.125 in. (3.175 mm) in all directions unless adjacent areas are specified as areas where blending is not permitted.
(d) It is better to blend sharp impact damage that is within acceptable limits than it is to accept that damage. The sharper the impact, the better it is to blend the damaged area.
(e) It is recommended that you make one single blend when the adjacent damage is so close together that the minimum length-to-depth blend ratio cannot be done independently.
(f) The depth of the blend must be as deep as necessary to remove the damage with the repair limits specified.
(g) The best blends are the ones that are smooth, continuous and round-bottomed that extend outboard from the damage area as much as necessary. Refer to the step that follows.
(h) For rotating parts, the length of the blend must be a minimum of 15 times the maximum depth of the blend in all directions. For non-rotating parts, the length of the blend must be a minimum of 10 times the maximum depth of the blend in all directions.
(i) For local damage in the form of raised material, manual blending (that is, blending by hand) is the preferred method. Refer to the manual blending steps.
(j) When blending on a cylindrical surface, blend in the circumferential direction.
(k) Blend engine radial members in a radial direction.
(l) For parts that are smaller than 1.75 in. (44.45 mm) in length, the manual blending procedure that follows is recommended.
(m) Manual blending (Blending by hand):
1 Manual blending is done with abrasive stones, abrasive paper, abrasive pads, files, emery cloth and/or crocus cloth.
(2) Visual inspection of the blends:
(a) The surface finish of the blended area must be as smooth as, or smoother, than the initial surface. You can compare the surface finish with the adjacent non-blended surface.
(b) All transitions from blended to non-blended areas must be smooth and continuous.
(c) If the blended area intersects adjacent radii, the initial radius contour must be restored.
(d) If the blended area intersects a corner, break the sharp edges 0.003 in. (0.08 mm) - 0.015 in. (0.38 mm).
(3) Buffing/polishing (Optional):
(a) Buffing is an optional operation that you can use to get the necessary surface finish while blending.
1 Buff reworked area(s) with a Brush (Material No.P05-058) , a POWER TOOL and Buffing Polishing Compound (Material No.P05-066) or Silicon Carbide Deburring Compound (Material No.P05-384) .
2 Use minimum pressure when you apply the buffing brush to the part to prevent heat build-up.
3 Buff engine radial members in a radial direction.
4 Buff cylindrical surfaces in a circumferential direction.
(b) Polishing is an operation that can be used to smooth minor scratches and burrs with fine abrasive paper, abrasive cloth, crocus cloth, emery cloth or Scrub Pad (Material No.P05-421) orP05-422 pad, scrub
(4) Local touch-up after blending:
(a) Aluminum Anodized Parts - To prevent corrosion damage on aluminum anodized parts after blending, do a local touch-up of the repair (Ref. AMM TASK 70-28-00-910-803).
(b) Blend to a sufficient depth to remove all the damage that you can see plus 0.002 in. (0.051 mm) - 0.003 in. (0.076 mm) of material within the repair limits specified.
(c) Blending must start with the coarser grades of resilient flexible abrasive-impregnated wheels, brushes or points for the initial removal of damage, but not coarser than is necessary to remove the damage.
(d) Finish blending the part with the finer grades of abrasive until the surface is as smooth as, or smoother than, the adjacent surfaces.
(e) Use grades of abrasives in the order that follows:
1 80 mesh silicon carbide or aluminum oxide grit
2 120 mesh silicon carbide or aluminum oxide grit
3 180 mesh silicon carbide or aluminum oxide grit
4 Optional: Use Polishing Compound (Material No.P05-354) or Polishing Compound (Material No.P05-426) withP05-353 Cloth Wheel (Non-coated)
(1) General
(a) Blending is an operation that is used to remove nicks, scratches, high metal and other surface irregularities by intentional removal of base metal. Manual or mechanical methods are used to make shallow and smooth surface depressions that reduce the stress concentration from the damaged area by the distribution of the stress concentration over larger, more tolerant areas.
(b) Before you start any blend repair, make sure that the part is crack-free (Ref. AMM TASK 70-25-00-910-801).
(c) Non-toleranced enclosed areas defined in blend repairs are to corners, points of tangency between surfaces or at points opposite one of these locations. Enclosed areas will assume a tolerance of plus 0.125 in. (3.175 mm) in all directions unless adjacent areas are specified as areas where blending is not permitted.
(d) It is better to blend sharp impact damage that is within acceptable limits than it is to accept that damage. The sharper the impact, the better it is to blend the damaged area.
(e) It is recommended that you make one single blend when the adjacent damage is so close together that the minimum length-to-depth blend ratio cannot be done independently.
(f) The depth of the blend must be as deep as necessary to remove the damage with the repair limits specified.
(g) The best blends are the ones that are smooth, continuous and round-bottomed that extend outboard from the damage area as much as necessary. Refer to the step that follows.
(h) For rotating parts, the length of the blend must be a minimum of 15 times the maximum depth of the blend in all directions. For non-rotating parts, the length of the blend must be a minimum of 10 times the maximum depth of the blend in all directions.
(i) For local damage in the form of raised material, manual blending (that is, blending by hand) is the preferred method. Refer to the manual blending steps.
(j) When blending on a cylindrical surface, blend in the circumferential direction.
(k) Blend engine radial members in a radial direction.
(l) For parts that are smaller than 1.75 in. (44.45 mm) in length, the manual blending procedure that follows is recommended.
(m) Manual blending (Blending by hand):
1 Manual blending is done with abrasive stones, abrasive paper, abrasive pads, files, emery cloth and/or crocus cloth.
NOTE: Blending can be done with more than one grade of abrasive (coarse to fine, as necessary) to remove damage and get the specified surface finish. Be sure to start with the least aggressive abrasive needed to remove the damage.
(n) Mechanical blending (Power blending): CAUTION:
DO NOT OVERHEAT THE PART OR DAMAGE CAN OCCUR.
1 When blending, use a POWER TOOL (electric or air) with abrasive-impregnated wheels, stones and/or pads. NOTE: Blending can be done with more than one grade of abrasive (coarse to fine, as necessary) to remove damage and get the specified surface finish. Be sure to start with the least aggressive abrasive needed to remove the damage.
2 Use minimum pressure when you apply the BORESCOPE - BLENDING to the part to prevent heat build-up. Do not let abrasive wheels become loaded up with any particles remaining from blending. (2) Visual inspection of the blends:
(a) The surface finish of the blended area must be as smooth as, or smoother, than the initial surface. You can compare the surface finish with the adjacent non-blended surface.
(b) All transitions from blended to non-blended areas must be smooth and continuous.
(c) If the blended area intersects adjacent radii, the initial radius contour must be restored.
(d) If the blended area intersects a corner, break the sharp edges 0.003 in. (0.08 mm) - 0.015 in. (0.38 mm).
(3) Buffing/polishing (Optional):
(a) Buffing is an optional operation that you can use to get the necessary surface finish while blending.
1 Buff reworked area(s) with a Brush (Material No.P05-058) , a POWER TOOL and Buffing Polishing Compound (Material No.P05-066) or Silicon Carbide Deburring Compound (Material No.P05-384) .
2 Use minimum pressure when you apply the buffing brush to the part to prevent heat build-up.
3 Buff engine radial members in a radial direction.
4 Buff cylindrical surfaces in a circumferential direction.
(b) Polishing is an operation that can be used to smooth minor scratches and burrs with fine abrasive paper, abrasive cloth, crocus cloth, emery cloth or Scrub Pad (Material No.P05-421) or
(4) Local touch-up after blending:
(a) Aluminum Anodized Parts - To prevent corrosion damage on aluminum anodized parts after blending, do a local touch-up of the repair (Ref. AMM TASK 70-28-00-910-803).
CAUTION:
WHEN YOU BLEND ROTATING COMPONENTS, DO THE PROCEDURE IN THE ORDER GIVEN IN THE PROCEDURE TO PREVENT DAMAGE TO THE PART.
(5) Special instructions for the blending of rotating parts: NOTE: Be sure to follow all the requirements in the blending and buffing/polishing procedures above.
(a) In areas where shotpeening is necessary, on-wing blending is not permitted. Blend only as specified in the specific AMM maintenance task. (b) Blend to a sufficient depth to remove all the damage that you can see plus 0.002 in. (0.051 mm) - 0.003 in. (0.076 mm) of material within the repair limits specified.
(c) Blending must start with the coarser grades of resilient flexible abrasive-impregnated wheels, brushes or points for the initial removal of damage, but not coarser than is necessary to remove the damage.
(d) Finish blending the part with the finer grades of abrasive until the surface is as smooth as, or smoother than, the adjacent surfaces.
(e) Use grades of abrasives in the order that follows:
1 80 mesh silicon carbide or aluminum oxide grit
2 120 mesh silicon carbide or aluminum oxide grit
3 180 mesh silicon carbide or aluminum oxide grit
4 Optional: Use Polishing Compound (Material No.P05-354) or Polishing Compound (Material No.P05-426) with