TASK 70-33-59-300-503 The Procedure To Remove Flame Spray Coatings

DMC:V2500-00-70-33-59-00A-653A-D|Issue No:002.00|Issue Date:2021-05-01

Export Control

EAR Export Classification: Not subject to the EAR per 15 C.F.R. Chapter 1, Part 734.3(b)(3), except for the following Service Bulletins which are currently published as EAR Export Classification 9E991: SBE70-0992, SBE72-0483, SBE72-0580, SBE72-0588, SBE72-0640, SBE73-0209, SBE80-0024 and SBE80-0025.

Copyright

© IAE International Aero Engines AG (2001, 2014 - 2021) The information contained in this document is the property of © IAE International Aero Engines AG and may not be copied or used for any purpose other than that for which it is supplied without the express written authority of © IAE International Aero Engines AG. (This does not preclude use by engine and aircraft operators for normal instructional, maintenance or overhaul purposes.).

Applicability

All

Common Information

TASK 70-33-59-300-503 The Procedure To Remove Flame Spray Coatings

Table of Contents

Introduction

Equipment and Materials

Safety Precautions

Subtask 70–33–59–500–001

Permitted Methods to Remove the Coatings

Prepare the Parts

The Procedure to Remove the Coating with:

Nitric Acid Solution

Alkali Paint Removal and Derusting Solutions

Cyanide Solution

10 Percent Sulfuric Acid Solution

Electrolytic Rochelle Carbonate and Sodium Carbonate Solutions

Alkaline Permanganate Solution

Dry Non-Metallic Abrasive Blasting

Nitric Acid/Hydrogen Peroxide Solution

SUBTASK 70-33-59-100-009

Electrolytic 10 Percent Sulfuric Acid Solution

Enthone GT 376 Solution

Inhibited Hydrochloric Acid Solution

SUBTASK 70-00-59-300-012

Aqua Regia

Hydrochloric Acid and Wetting Agent

Enstrip GT 317

Introduction

This TASK gives the procedures for removal of different flame spray coatings. The procedures must only be used on the base materials specified.

To identify the consumable materials, refer to the Consumable Materials Index.

Preliminary Requirements

Pre-Conditions

NONE

Support Equipment

NONE

Consumables, Materials and Expendables

NameManufacturerPart Number / IdentificationQuantityRemark
CoMat 05-001 ABRASIVE MEDIUM, ALUMINIUM OXIDE, 20/30 GRADELOCALCoMat 05-001

Spares

NONE

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURER'S SAFETY DATA SHEETS FOR CONSUMABLE MATERIAL SAFETY INFORMATION (SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE HAZARD DATA, EXPLOSION HAZARD DATA, REACTIVITY HAZARD DATA, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE, AND CONTROL MEASURES) AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

Procedure

    1. SUBTASK 70-33-59-500-001 Safety Precautions

      1. Precautions that apply to all chemicals are:

      1. WARNING

        IT IS VERY IMPORTANT TO TAKE EVERY POSSIBLE PRECAUTION TO PREVENT CHEMICAL (SOLID OR SOLUTION) CONTACT WITH THE EYES OR BARE SKIN. WEAR APPROPRIATE PROTECTIVE CLOTHING, WHICH INCLUDES GOGGLES AND RUBBER GLOVES, WHEN YOU MAKE UP AND USE THE SOLUTIONS IN THIS PROCEDURE. EXAMINE RUBBER GLOVES REGULARLY FOR PIN HOLES AND REPLACED AND DISCARD THEM AS NECESSARY. KEEP EYE-WASH BOTTLES AND OTHER APPLICABLE FIRST AID EQUIPMENT AS CLOSE AS POSSIBLE TO THE WORK AREA.
        IF CONTAMINATION OF THE EYES OCCURS, FLUSH THE EYES IMMEDIATELY WITH WATER, SUFFICIENT TO REMOVE THE CONTAMINATION. GO FOR MEDICAL TREATMENT IMMEDIATELY.
        IF CONTAMINATION OF THE SKIN OCCURS, CLEAN YOUR SKIN WITH A LARGE QUANTITY OF CLEAN WATER THAT FLOWS. ALL BURNS, LARGE OR SMALL, MUST BE EXAMINED AT THE NEAREST FIRST AID POST.

        WARNING

        THE FIRST AID POST MUST BE TOLD WHICH SOLUTION (FOR EXAMPLE, THE ACIDS INVOLVED) CAUSED THE BURN.

        WARNING

        FINGER NAILS MUST BE KEPT SHORT AND MUST ALWAYS BE FULLY CLEANED BEFORE YOU EAT, DRINK OR SMOKE. YOU MUST NOT EAT, DRINK OR SMOKE, AT PLACES WHERE CHEMICALS ARE KEPT OR USED. ITEMS THAT ARE USED TO EAT OR DRINK WITH MUST NOT BE KEPT AT LOCATIONS WHERE CHEMICALS ARE KEPT OR USED.

        WARNING

        SAFETY NOTICES MUST ALWAYS BE PUT IN LOCATIONS WHERE THEY CAN BE EASILY SEEN.

        Chemical precautions.

      2. Cyanide specific precautions and warning signs are as follows:

        1. WARNING

          CYANIDE SALTS AND/OR SOLUTIONS ARE EXTREMELY RAPID POISONS AND RELEASE DEADLY HYDRO-CYANIC GAS IN CONTACT WITH ACIDS.

          WARNING

          CYANIDE SALTS AND SOLUTIONS MUST BE KEPT APART FROM ACIDS.

          WARNING

          CYANIDE MUST ALWAYS BE KEPT AT A SAFE LOCATION, WHERE ACCESS IS ONLY AVAILABLE TO APPROVED PERSONS.

          WARNING

          A SUPPLY OF CYANIDE ANTIDOTE MUST ALWAYS BE EASILY AVAILABLE.

          WARNING

          FUME EXTRACTION IS ESSENTIAL.

          Poisoning will occur:

        1. If you swallow cyanide

        2. If you breathe hydro-cyanic gas

        3. Cyanide or hydro-cyanic gas absorbs through your skin.

        2. Warning indications of poisoning:

        1. Dizziness, nausea, general weakness, and headache

        2. Palpitations

        3. Feeling of suffocation and tightness in the throat

        4. Pallor, deep breathing, and unconsciousness.

      3. Chromic acid solution specific precautions are:

      1. WARNING

        CHROMIC ACID SPRAY IS DANGEROUS IF INHALED, BECAUSE IT CAUSES ULCERS IN THE NOSE AND, IN SOME CASES, PERFORATION OF THE NASAL SEPTUM. CHROMIC ACID SALTS AND SOLUTIONS IN CONTACT WITH THE SKIN CAN CAUSE CHROME SORES. ULCERS CAN FORM IF CHROMIC ACID GETS IN TO CUTS AND ABRASIONS. CUTS AND ABRASIONS, WHICH DO NOT HEAL, MUST BE REPORTED, IMMEDIATELY, TO THE MEDICAL DEPARTMENT.

        WARNING

        CHROMIC ACID MUST NOT BE USED UNLESS THE FUME EXTRACTION PLANT IS IN OPERATION AND IS FULLY SERVICEABLE.

        WARNING

        PROTECTIVE CLOTHING MUST BE WORN, THAT IS, PROTECTIVE GLOVES, OVERALLS, GOGGLES OR FACE VISOR AND SAFETY SHOES OR BOOTS. BARRIER CREAM MUST BE APPLIED TO THE HANDS AND FOREARMS BEFORE YOU START WORK.

        WARNING

        SMOKING AND THE CONSUMPTION OF FOOD NEAR THE CHROMIC ACID BATH ARE PROHIBITED.

        WARNING

        CHROMIC ACID IS STRONGLY OXIDIZING AND HAS SOME FIRE RISK (THAT IS, POSSIBLE SPONTANEOUS COMBUSTION OF ORGANIC MATERIALS). COMBUSTIBLE MATERIALS INCLUDE RAGS AND SAWDUST, WHICH HAVE ABSORBED CHROMIC ACID SOLUTION. SUCH CONTAMINATED MATERIALS MUST BE PUT FULLY IN A SOLUTION OF SODIUM BISULFITE TO MAKE NEUTRAL THE CHROMIC ACID; THEN DISCARD THE SOLUTION AS SPECIAL WASTE. THE SOLID MATERIAL MUST THEN BE FLUSHED WITH WATER BEFORE DISPOSAL.

        In the United Kingdom, this process is controlled by the Health and Safety at Work Act, which specifies the responsibilities of all the people that work with chromium solutions. In addition to which there is a requirement that every person employed must be examined by the Appointed Factory Doctor every 14 days. Over and above the latter, it is the duty of the Occupier of the work place to arrange for a responsible person to examine the hands and forearms of all persons employed, two times each week.

      4. Sodium hydroxide specific precautions:

      1. WARNING

        CARE MUST BE TAKEN WHEN YOU ADD COMPOUNDS WHICH CONTAIN SOLID SODIUM HYDROXIDE TO WATER, BECAUSE HEAT IS GIVEN OFF WHEN THE COMPOUND DISSOLVES. MAKE MUCH MOVEMENT OF THE SOLUTION, WITH AIR OR MECHANICAL METHODS, AS YOU ADD THE COMPOUND TO THE SURFACE OF THE SOLUTION. DO NOT ADD LARGE QUANTITIES OF THE COMPOUND, TO ONE SMALL AREA OF THE TANK, BECAUSE THE SOLUTION WILL BOIL.

        Sodium hydroxide precautions.

      5. Nitric and sulfuric acid specific precautions are:

      1. CAUTION

        SOME PROCEDURES IN THIS TASK RELEASE HYDROGEN DURING COATING REMOVAL. THIS CAN CAUSE HYDROGEN EMBRITTLEMENT CRACKING. THUS STEEL PARTS WITH A TENSILE STRENGTH OF MORE THAN 100 MPA OR A HARDNESS OF 302 HB OR 310 HV MUST BE STRESS-RELIEVED AND DE-EMBRITTLEMENT HEAT TREATED AT 374 TO 410 DEG F (190 TO 210 DEG C) FOR ONE HOUR AT TEMPERATURE. THIS MUST BE DONE BEFORE AND AFTER THE PARTS ARE PUT IN THE STRIPPING SOLUTION.

        CAUTION

        THE HEAT TREATMENTS ARE ALSO NECESSARY ON STEELS WHERE THE HARDNESS RANGE INCLUDES 1000 MPA OR 302 HB (FOR EXAMPLE, 930 TO 1080 MPA OR 283 TO 321 HB).

        Nitric and sulfuric acid precautions.

    2. SUBTASK 70-33-59-300-001-001 Permitted Methods to Remove the Coatings

    1. NOTE

      *a Heat treatment will be necessary after the alkali derusting treatment, for some high strength, or hardness martensitic steels.

      NOTE

      *b Step (alkali derusting) with the solution made-up to SUBTASK 70-33-59-100-002-001 (sodium hydroxide) only and not any alternative.

      NOTE

      *c Ultra high pressure water cannot be used to remove D-Gun applied coatings because the structure of the coating is not suitable.

      NOTE

      *d Ultra high pressure water does not always remove chromium carbide/nichrome coatings satisfactorily.
      Table 2. Cross Reference Table: CoMat Number to Coating Type

      CoMat Number

      Coating Type

      Coating Group

      CoMat 03-036

      CoMat 03-037

      CoMat 03-038

      CoMat 03-248

      CoMat 03-408

      CoMat 03-434

      CoMat 03-435

      CoMat 03-448

      Nickel, Nickel Aluminide Coatings

      1 (NiAl)

      CoMat 03-319

      CoMat 03-427

      CoMat 03-428

      CoMat 03-430

      CoMat 03-443

      CoMat 03-453

      Ceramic, Cermet, Alumina, Zirconia, and Magnesium Oxide Coatings

      2 (Ceramics)

      CoMat 03-304

      CoMat 03-097

      Nickel Graphite Coatings (75:25)

      3 (Ni Graphite)

      CoMat 03-057

      CoMat 03-058

      CoMat 03-086

      CoMat 03-236

      CoMat 03-263

      CoMat 03-273

      Aluminum and Aluminum Alloys, Aluminum Graphite, Aluminum Polyester, and Silicon Aluminum Coatings

      4 (Al base)

      CoMat 03-302

      CoMat 03-320

      CoMat 03-321

      CoMat 03-277

      CoMat 03-321

      Tungsten Carbide/Cobalt Coatings

      5 (WC/Co)

      CoMat 03-314

      Chromium Carbide and Nichrome Coatings

      6 (CrC/NiCr)

      CoMat 03-277

      CoMat 03-278

      CoMat 03-309

      CoMat 03-313

      CoMat 03-318

      Cobalt Based Alloy Coatings

      7 (Co base)

      CoMat 03-265

      NiCrAl Coatings

      8 (NiCrAl)

      CoMat 03-262

      CoNiCrAlY Coatings

      9 (CoNiCrAlY)

      CoMat 03-422

      12 Percent Chromium Steel Coatings

      10 (12 Percent Cr Fe)

      CoMat 03-077

      CoMat 03-302

      CoMat 03-320

      CoMat 03-321

      CoMat 03-403

      CoMat 03-437

      CoMat 03-438

      CoMat 03-440

      80/20 Nickel Chromium Coatings

      11 (80/20 NiCr)

      CoMat 03-402

      CoMat 03-436

      Nickel, Nickel Aluminum Coatings

      12 (Ni, NiAl)

      CoMat 03-261

      CoMat 03-408

      CoMat 03-448

      Copper/Nickel/Indium Coatings

      13 (Cu base)

      Table 3. Methods for Low Alloy Steel and Martensitic Heat and Corrosion Resistant Steel Substrates

      Low Alloy Steel

      Martensitic Heat and Corrosion Resistant Steel

      1 (NiAl)

      followed by

      followed by

      2 (Ceramics)

      3(Ni Graphite)

      followed by

      Step to remove the bond coat

      followed by

      4 (Al base)

      followed by

      and

      to remove the bond coat

      See note *a

      followed by

      and

      to remove the bond coat

      See note *a

      5 (WC/Co)

      SUBTASK 70-33-59-300-009

      6 (CrC/NiCr)

      followed by

      followed by

      See note *d

      See note *d

      7 (Co base)

      8 (NiCrAl)

      NA

      followed by

      9 (CoNiCrAlY)

      NA

      10 (12 percent Cr Fe)

      NA

      followed by

      or Step to remove the bond coat

      11 (80/20 NiCr)

      12 (Ni, NiAl)

      followed by

      followed by

      Table 4. Nickel and Cobalt Heat Resisting Alloys, Austenitic Corrosion and Heat Resistant Steel Substrates

      Nickel and Cobalt Heat Resisting Alloys,

      Austenitic Corrosion and Heat Resistant Steel Substrates

      1 (NiAl)

      followed by

      followed by

      followed by

      followed by

      2 (Ceramics)

      followed by

      3 (Ni Graphite)

      followed by

      followed by

      4 (Al base)

      followed by

      and

      to remove the bond coat

      followed by

      and

      to remove the bond coat

      See note *a

      5 (WC/Co)

      SUBTASK 70-33-59-300-009

      SUBTASK 70-33-59-300-009

      See note *c

      6 (CrC/NiCr)

      followed by

      followed by

      See note *d

      See note *d

      7 (Co base)

      8 (NiCrAl)

      followed by

      NA

      followed by

      9 (CoNiCrAlY)

      followed by

      10 (12 percent Cr Fe)

      followed by

      or Step to remove the bond coat

      followed by

      or Step to remove the bond coat

      11 (80/20 Ni/Cr)

      SUBTASK 70-33-59-300-012

      12 (Ni, NiAl)

      followed by

      followed by

      followed by

      followed by

      Table 5. Aluminium and Titanium Subtrates

      Aluminium Subtrates

      Titanium Subtrates

      1 (NiAl)

      followed by

      followed by

      followed by

      2 (Ceramics)

      3 (Ni Graphite)

      followed by

      followed by

      4 (Al base)

      (see note *b)

      followed by

      and

      to remove the bond coat

      5 (WC/Co)

      See note *c

      SUBTASK 70-33-59-300-009

      See note *c

      6 (CrC/NiCr)

      7 (Co base)

      8 (NiCrAl)

      NA

      10 (12 percent Cr Fe)

      followed by

      Step to remove the bond coat

      Removes top coat and bondcoat

      11 (80/20 NiCr)

      12 (Ni, NiAl)

      followed by

      followed by

      followed by

      followed by

      13 (Cu base)

    3. SUBTASK 70-33-59-300-001 Prepare the Parts

      1. CAUTION

        TITANIUM ALLOYS MUST ONLY BE VAPOR DEGREASED WHEN SPECIFIED IN THE ENGINE MANUAL.

        NOTE

        Some stripping procedures can cause damage to paint; therefore, it can be necessary to paint the parts after the removal of the metal spray coating.

        Clean the part by one of these methods:

      1. TASK 70-11-03-300-503, SUBTASK 70-11-03-300-001-001.

      2. TASK 70-11-03-300-503TASK 70-11-03-300-501, SUBTASK 70-11-03-300-001-002.

      3. Vapor degrease with SPM TASK 70-11-01-300-503.

    2. When specified in the Engine Manual, stress-relieve parts at 374 to 410 deg F (190 to 210 deg C) for one hour minimum.

    3. Mask the surfaces that do not need to be stripped as specified by the Engine Manual. Refer to SPM TASK 70-38-24-300-503 for details on masking methods.

    4. NOTE

      When an electrolytic procedure is used, the parts are made the anode; thus, good electrical contact is necessary.

      Put the parts on suitable fixtures for the process necessary, for example, wire, or hooks, or jigs, or put them in suitable wire baskets.

    5. NOTE

      If a chemical procedure is not available or too difficult to apply, remove the metal spray coating by machining.

      Strip the coating by the applicable method. Refer Step for the appropriate methods for the specific type of coating.

    4. SUBTASK 70-33-59-300-002 The Procedure to Remove the Coating with the Nitric Acid Solution

      CAUTION

      THIS PROCEDURE WILL STRIP OR CAUSE DANGEROUS DAMAGE TO NICKEL COATINGS ON PARTS. MASK COATINGS WHICH ARE NOT TO BE REMOVED. DO NOT USE THIS METHOD ON SILVER OR COPPER BRAZED PARTS.

    1. For instructions to make-up the solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-001. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-001.

    2. Prepare the part to Step.

    3. Put the coating to be removed into the solution. Stripping is complete when gassing stops.

    4. Wash the parts fully in clean cold water. If necessary, use a bristle brush to remove unwanted material. Alternatively, pressure wash the parts.

    5. Remove the wire, hooks, jigs, and other fixtures and wash the parts again in clean cold water.

    6. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean, dry air.

    7. Make sure all the coating has been removed fully. If coating remains, prepare the part again (refer to Step) and repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or by machining.

    8. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    9. When specified in the Engine Manual, de-embrittle heat treat the parts at 374 to 410 deg F (190 to 210 deg C) for one hour minimum. This must be done as soon as possible and not more than 16 hours after the removal procedure is completed.

    5. SUBTASK 70-33-59-300-003 The Procedure to Remove the Coating wiith the Alkali Paint Removal and Derusting Solutions

      WARNING

      ALKALI DERUSTERS CONTAIN SODIUM HYDROXIDE. REFER TO THE SODIUM HYDROXIDE SPECIFIC SAFETY PRECAUTIONS.

    1. For instructions to make-up the solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-002-001 and SUBTASK 70-33-59-100-002-002. For control of the solutions, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-002

    2. For titanium parts, use the solution in SUBTASK 70-33-59-100-002-001 only. Do not use the solutions to SUBTASK 70-33-59-100-002-002 on titanium parts.

    3. Prepare the part by Step.

    4. Put the coated area of the part into the solution for a maximum of five hours. Stripping is complete when no more gas is given off.

    5. Wash the parts fully in clean cold water or pressure wash the parts. If necessary, use a bristle brush to remove unwanted material.

    6. Remove the wire hooks, jigs, and other fixtures and wash the parts and fixtures fully in clean cold water.

    7. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    8. Make sure all the coating has been removed fully. If coating remains, prepare the part again (refer to Step) and repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or by machining.

    9. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    10. When specified in the Engine Manual, de-embrittle heat treat the parts at 374 to 410 deg F (190 to 210 deg C) for one hour minimum. This must be done as soon as possible after the removal procedure is completed.

    6. SUBTASK 70-33-59-300-004 The Procedure to Remove the Coating with the Cyanide Solution

      WARNING

      THIS SUBTASK USES A CYANIDE SOLUTION.

    1. For instructions to the make-up the solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-003. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-003.

    2. Prepare the part by Step.

    3. Put the coating to be removed into the cyanide solution.

      NOTE

      Some metal/plasma/detonation coatings can take 24 hours to strip and this can be related to coating thickness. High Velocity (D-gun, or HVOF) coatings will not be removed by this process.

    4. Examine the parts regularly while the parts are in the solution to monitor the removal of the coating. This is because there is no visible indication given by the solution that the stripping is complete.

    5. Wash the parts fully in clean cold water or pressure wash the parts. If necessary, use a bristle brush to remove unwanted material.

    6. Remove the wire hooks, jigs, and other fixtures and wash the parts and jigs fully.

    7. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean, dry air.

    8. Make sure all the coating has been removed fully. If coating remains, prepare the part again by the method in Step) and then repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or by machining.

    9. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    7. SUBTASK 70-33-59-300-005 The Procedure to Electrolytically Remove the Coating with the 10 Percent Sulfuric Acid Solution

    1. For instructions to make-up the 10 percent solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-004. For control of the 10 percent solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-004.

    2. Make sure the strength of the solution is as specified.

    3. Prepare the part by Step.

    4. Make the coating of the parts the anode.

    5. The stripping current is to be 0.6 A/sq inch (1000 A/sq m) at between 6 to 8 volts DC.

    6. Put the parts in the solution until stripping is complete. The stripping time is related to the type, thickness, and condition of the coating.

    7. Wash the parts fully in clean cold water or pressure wash the parts. If necessary, use a bristle brush to remove unwanted material. Alternatively, use an air/water gun to remove remaining material.

    8. Remove the wire hooks, jigs, and other fixtures and wash fully.

    9. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean, dry air.

    10. Make sure all the coating has been removed fully. If coating remains, prepare the part again by the method in Step and repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or by machining.

    11. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    8. SUBTASK 70-33-59-300-006 The Procedure to Remove the Coatings with the Electrolytic Rochelle Carbonate and Sodium Carbonate Solutions

      CAUTION

      THIS SOLUTION CAN CAUSE DAMAGE TO SOME NICKEL OR ALLOYS.

    1. For instructions to make-up the Rochelle carbonate salt solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-005-001; to make-up the alternative Sodium carbonate salt solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-005-001-A01. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-005.

    2. Prepare the part by Step.

    3. Make the coating the anode.

    4. The stripping current is to be 0.6 A/sq inch (1000 A/sq m) at 6.5 volts maximum.

    5. Put the parts in the solution until stripping is complete. The stripping time is related to the type, thickness, and condition of the coating.

    6. Wash the parts in clean cold water or pressure wash the parts. If necessary, use a bristle brush to remove unwanted material.

    7. Remove the wire hooks, jigs, and other fixtures and wash the parts and fixtures fully in cold, clean water.

    8. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    9. Make sure all the coating has been removed fully. If coating remains, prepare the part again (refer to Step) and repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or by machining.

    10. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    9. SUBTASK 70-33-59-300-007 The Procedure to Remove the Coating with the Alkaline Permanganate Solution

      WARNING

      ALKALI PERMANGANATE SOLUTIONS CONTAIN SODIUM HYDROXIDE. REFER TO THE SODIUM HYDROXIDE SPECIFIC SAFETY PRECAUTIONS.

    1. For instructions to make-up the Alkaline permanganate, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-006-001. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-006.

    2. If the parts were heat treated in oxidizing conditions, it will be necessary to descale the surface. Refer to SPM TASK 70-11-11-300-503 or Step.

    3. Prepare the part by Step.

    4. Put the coating to be removed into the solution (heated to a temperature between 185 to 203 deg F (85 to 95 deg C)). This procedure only degrades the coating. The activity of the solution and the coating thickness will have an effect on the time the parts are in the solution. This will be between 12 and 20 hours.

    5. Neutralize the parts, for one minute, in the chromic acid neutralizing solution (SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-007) or the nitric acid neutralizing solution (SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-008). The chromic acid solution is to be at a temperature of 149 to 158 deg F (65 to 70 deg C) and the nitric acid solution at room temperature.

    6. Abrasive blast the parts to complete removal of the coating. Refer to Step.

    7. Wash the parts in clean cold water or pressure wash the parts. If necessary, use a bristle brush to remove unwanted material.

    8. Remove the wire hooks, jigs, and other fixtures and wash the parts and fixtures again.

    9. To dry the parts, put the parts fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    10. Make sure all the coating has been removed fully. If coating remains, prepare the part again (refer to Step) and repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or by machining.

    11. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    10. SUBTASK 70-33-59-300-008 The Procedure to Remove the Coating by Dry Non-Metallic Abrasive Blasting

      1. Abrasive blast the parts. Refer to SPM TASK 70-12-02-120-501.

      1. Use CoMat 05-001 ABRASIVE MEDIUM, ALUMINIUM OXIDE, 20/30 GRADE where possible, at 30 psi (207 KPa) with a pressure-type machine or 75 psi (517 KPa) with vacuum-type equipment. The nozzle-to-workpiece distance is 3 inch (76 mm). Alternative, abrasive grit can be used.

      2. Where grit contamination of surfaces is a problem, the parts must be pressure washed to make sure all the grit and other all remaining material is removed.

      3. Distortion can occur in thin walled components. Use bracing jigs, or smaller aluminum oxide grit and/or lower pressures.

      4. Because grit contamination occurs quickly, it is recommended that the equipment is only used for the removal of metal spray coatings. Alternatively, discard the grit after stripping is completed.

    11. SUBTASK 70-33-59-100-009 The Procedure to Remove the Coating with the Nitric Acid/Hydrogen Peroxide Solution

    1. For instructions to make-up the Nitric acid/Hydrogen peroxide solution, refer to SPM TASK 70-33-59-100-501, Step. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-009.

    2. Prepare the part by Step.

    3. Put the coating to be removed into the solution at ambient temperature. Remove the parts from the solution after intervals of time and bristle brush to remove the denatured coating.

    4. Put the parts back into the solution until no more smut forms on the surfaces of the parts.

    5. Wash the parts in clean cold water or pressure wash the parts. If necessary use a bristle brush to remove unwanted material.

    6. Remove the wire hooks, jigs, and other fixtures and wash the parts and fixtures again.

    7. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    8. Make sure all the coating has been removed fully. If coating remains, prepare the part again (refer to Step) and repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or machining.

    9. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    12. SUBTASK 70-33-59-300-010 The Procedure to Electrolytically Remove the Coating with the 30 Percent Sulfuric Acid Solution

    1. For instructions to make-up the 30 percent solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-010. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-004.

    2. Make sure the strength of the solution is as specified.

    3. Prepare the part by Step.

    4. Make the coating of the parts the anode.

    5. The stripping current is to be 0.6 A/sq inch (1000 A/sq m) at between 6 to 8 volts DC.

    6. Put the parts in the solution until stripping is complete. The stripping time is related to the type, thickness, and condition of the coating.

    7. Wash the parts fully in clean cold water or pressure wash the parts. If necessary, use a bristle brush to remove unwanted material. Alternatively, use an air/water gun to remove remaining material.

    8. Remove the wire hooks, jigs, and other fixtures and wash fully.

    9. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    10. Make sure all the coating has been removed fully. If coating remains, prepare the part again by the method in Step and repeat this subtask. Alternatively, remove the remaining coating by abrasive blasting (Step) or by machining.

    11. Apply temporary corrosion protection, if applicable. Refer to SPM TASK 70-38-05-380-501.

    13. SUBTASK 70-33-59-300-011 The Procedure to Remove the Coatings with Enthone GT 376 Solution

    1. For instructions to make-up the Enthone GT 376 refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-011. For control of the Enthone GT 376 solution refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-010.

    2. Prepare the part to Step.

    3. Put the coating to be removed in the solution for 30 minutes.

    4. Wash the parts in clean cold water.

    5. Air/water blast to remove unwanted material.

    6. Repeat this subtask, if necessary, to remove all remaining coating, or abrasive blast by Step.

    14. SUBTASK 70-00-59-300-012 The Procedure to Remove the Coatings with Inhibited Hydrochloric Acid Solution

    1. For instructions to make-up the inhibited hydrochloric acid solution refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-012. For control of the solution refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-011.

    2. Prepare the part to Step.

    3. Put the coating to be removed into the solution for 30 minutes.

    4. Remove the parts from the inhibited hydrochloric acid solution and wash fully in clean cold water.

    5. Air/water blast to remove unwanted material.

    6. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    15. SUBTASK 70-33-59-300-013 The Procedure to Remove the Coatings with Aqua Regia

    1. For instructions to make-up the aqua regia solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-013. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-012.

    2. Prepare the part by Step.

    3. Put the coating to be removed into the solution. Remove at intervals and bristle brush to remove the denatured coating.

    4. Put into the aqua regia solution until no more smut is formed on the surface of the part.

    5. Remove the parts from the aqua regia solution and wash fully in clean cold water.

    6. Air/water blast to remove unwanted material.

    7. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    16. SUBTASK 70-33-59-300-014 The Procedure to Remove the Coatings with Hydrochloric Acid and Wetting Agent

    1. For instructions to make-up the hydrochloric acid and wetting agent solution, refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-014. For control of the solution, refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-013.

    2. Prepare the part by Step.

    3. Put the coating to be removed into the solution and leave it in the solution for 24 hours.

    4. Remove the parts from the hydrochloric acid solution and wash fully in clean cold water.

    5. Air/water blast to remove unwanted material.

    6. To dry the parts, put them fully in clean hot water at a temperature of 176 deg F (80 deg C) minimum. After removal from the hot water, remove all remaining water from the parts with a blast of clean dry air.

    7. If necessary, the part may be abrasive blasted to Step to remove all remaining coating.

    17. SUBTASK 70-33-59-300-015 The Procedure to Remove the Coatings with Enthone GT 317 Solution

    1. For instructions to make-up the Enthone GT 317 refer to SPM TASK 70-33-59-100-501, SUBTASK 70-33-59-100-015. For control of the Enthone GT 317 solution refer to SPM TASK 70-33-59-200-502, SUBTASK 70-33-59-200-014.

    2. Prepare the part to Step.

    3. Put the parts fully into solution for the time necessary to remove the coating. The rate at which the coating is remove is approximately 0.003 inch (0.076 mm) per hour. It is permitted to remove the parts at interval of time to remove denatured coating with a non-metallic stiff bristle brush.

    4. Wash the parts in clean cold water.

    5. Air/water blast to remove unwanted material.

    6. Repeat this subtask, if necessary, to remove all remaining coating, or abrasive blast by Step.

Requirements After Job Completion

Follow-On Conditions

NONE
Change Type:

Revision update to task to add CoMat 03-097, remove thermal spray coating material, update safety precautions and various editorial fixes. (REA20VC510)

Manufacturer Code:LOCAL
Enterprise Name:LOCALLY SUPPLIED
Manufacturer Code:LOCAL
Supply Number:CoMat 05-001
Type:sp01
Supply Short Name:CoMat 05-001 ABRASIVE MEDIUM, ALUMINIUM OXIDE, 20/30 GRADE
Supply Name:CoMat 05-001 ABRASIVE MEDIUM, ALUMINIUM OXIDE, 20/30 GRADE
Specification Groups:
Doc NumberType
Use one of the CoMat 05-001 letter suffix alternatives.
Suppliers:
ManufacturerRemarks
LOCAL