SOLVENT CLEANING 1. DESCRIPTION This section covers solvent cleaning procedures for metallic and non-metallic materials. These procedures may be used for general cleaning when solvents are required and must be used to clean surfaces prior to the application of adhesive, resin, or sealants. Cleaning solvents are toxic and flammable. Therefore, special precautions must be used whenever solvents are used for any purpose. Always follow the solvent manufacturer s directions. A fire extinguisher must be immediately available when using solvents. Adequate ventilation shall be provided and fresh air masks shall be used in all closed areas with marginal or insufficient ventilation. Skin protection in the form of protective gloves and eye protection must be worn when pouring or applying solvents. When solvent cleaning closed areas such as fuel tanks, eliminate spark hazards, electrically ground the aircraft, and fill the enclosed area with an inert gas such as argon or nitrogen. Apply the inert gas continuously until the tank is clean and dry. Always check the MSDS for the solvent being used for additional requirements and/or precautions to be followed when using a particular solvent. Special procedures may be required to dispose of used solvents. Page 1 15 Jun 2010
2. MAINTENANCE PRACTICES A. Solvent Cleaning Metal Parts Cleaning solvents are toxic and flammable. Skin protection and eye protection are required. Additionally, adequate ventilation and/or fresh air masks shall be used in all closed areas. (1) Approved Materials (a) Solvents Isopropyl Alcohol 99% or higher purity Acetone ASTM D-329 Mineral Spirits TT-T-291 I, II, or III Aliphatic Naptha TT-N-95 Type II Miscellaneous Sealant Removal and Cutting Tools - Remove sealant. Pipe Cleaners - Remove sealant in injectable gaps. Bristle Brush (non-nylon, non-metallic) Solvent Dispensers (polyethylene squirt bottle) Cotton cloth Cotton Gloves Protective Gloves (neoprene rubber) - Clean up. - Dispense solvents. - Surface - Handle cleaned surfaces. - Protect hands from chemicals. Goggles - Protect eyes from chemicals. (2) Preliminary Cleaning (a) Remove excess material (metal chips, shavings, lint, etc.) using a vacuum sweeper, clean bristle brush, etc. Page 2 15 Dec 2014
Clean area with a clean cloth dampened with cleaning solvent and immediately wipe area dry with a clean dry cloth. Do not allow cleaning solvent to air dry as a residue will remain on the surface. (3) Final Cleaning Final cleaning must be accomplished prior to applying any adhesive, or sealant. surfaces shall be thoroughly cleaned and dried before application of any adhesive or sealant. When handling cleaned surfaces, wear clean, white cotton gloves to prevent surface contamination. Surfaces shall be recleaned in the event of contamination. (a) Fold clean lint-free cloths in such a manner as to eliminate raw edges to reduce the possibility of lint contaminating the surface to be cleaned. Dampen one cloth with cleaning solvent from polyethylene squirt bottle. The cloth should not be saturated to a point where solvent drips. Extreme care is needed to clean hard to reach areas, corners, gaps, etc. A small paint brush, pipe cleaners, or cloth wrapped around wooden or phenolic tools may be used for slots, recesses, and other hard to reach areas. Do not allow cleaning solvent to air dry as a residue will remain on the surface, contaminating a following process. Never pour or spray cleaning solvent on aircraft structure because it will run back between structural layers, then run back out again after the cleaning operations are completed, bringing contamination to surfaces previously cleaned. (c) Thoroughly clean small areas at a time and immediately wipe area dry with a clean, dry, lint-free cloth. If adhesive or sealant is to be applied, always clean an area wider than the width of final product being applied. (d) Continue cleaning process until no discoloration is noted on the drying cloth. If primer is removed during cleaning and if the exposed metal surface will be completely covered by the sealing process, the exposed metal surface need not be further treated. Page 3 15 Jun 2010
B. Solvent Cleaning Composite Materials If fuel tank interior is to be cleaned, ground aircraft to suitable earth ground. Evacuate oxygen from fuel tank by filling tank with an inert gas such as nitrogen or argon. Gas should be applied continuously until tank is clean and dry. Laminates that come in contact with moisture must be dried before performing composite repairs. Cleaning solvents are toxic and flammable. Skin protection and eye protection are required. Additionally, adequate ventilation and/or fresh air masks shall be used in all closed areas. Isopropyl alcohol is the only cleaning agent recommended when preparing composite surfaces (excluding fuel compartments) for repair. When cleaning a composite surface in any of the fuel compartments, acetone is the recommended cleaning agent. Serials 2438 & subs: Do not allow isopropyl alcohol to contact fuel quantity sensor dial or cracking and crazing will occur. Serials 3026 & subs w/ Ice Protection and Perspective Avionics: Do not allow acetone to contact glycol quantity sensor dial or cracking and crazing will occur. (1) Approved Materials (a) Solvents Cleaner DX320, DX330, DX394, DX440, and SX1005 PPG Industries, Inc. Cleaning repair surfaces before apply paint manufactured by PPG Industries. Isopropyl Alcohol 99% or higher purity cleaning of composites before bonding process. Acetone ASTM D-329 Mineral Spirits TT-T-291 I, II, or III Aliphatic Naptha TT-N-95 Type II Miscellaneous Sealant Removal and Cutting Tools - Remove sealant. Pipe Cleaners - Remove sealant in injectable gaps. Page 4 15 Dec 2014 Bristle Brush (non-nylon, non-metallic) - Clean up.
Solvent Dispensers (polyethylene squirt bottle) - Dispense solvents. Cotton cloth Cotton Gloves Protective Gloves (neoprene rubber) - Surface - Handle cleaned surfaces. - Protect hands from chemicals. Goggles - Protect eyes from chemicals. (2) Preliminary Cleaning (a) Remove excess material (chips, shavings, lint, etc.) using a vacuum sweeper, clean bristle brush, etc. Clean area with a clean cloth dampened with solvent and immediately wipe area dry with a clean dry cloth. Do not allow solvent to air dry as a residue will remain on the surface. (3) Final Cleaning Final cleaning must be accomplished prior to applying adhesive, resin, or sealant. surfaces shall be thoroughly cleaned and dried before application of any adhesive, resin, or sealant. When handling cleaned surfaces, wear clean, white cotton gloves to prevent surface contamination. Surfaces shall be recleaned in the event of contamination. (a) (c) (d) Absorb all visible moisture on the laminate using a clean, lint-free, cotton cloth. Fold clean lint-free cloths in such a manner as to eliminate raw edges to reduce the possibility of lint contaminating the surface to be cleaned. Wipe affected area with solvent using a clean, lint-free, cotton cloth. Dampen one cloth with solvent. The cloth should not be saturated to a point where solvent drips. Extreme care is needed to clean hard to reach areas, corners, gaps, etc. A small paint brush, pipe cleaners, or cloth wrapped around wooden or phenolic tools may be used for slots, recesses, and other hard to reach areas. Do not allow cleaning solvent to air dry as a residue will remain on the surface, contaminating a following process. Never pour or spray cleaning solvent on aircraft structure because it will run back between structural layers, then run back out again after the cleaning operations are completed, bringing contamination to surfaces previously cleaned. (e) Thoroughly clean small areas at a time and immediately wipe area dry with a clean, dry, lint-free cloth. If adhesive, resin, or sealant is to be applied, always clean an area wider than the width of final product being applied. (f) Continue cleaning process until no discoloration is noted on the drying cloth. Page 5 15 Jun 2010
C. Solvent Cleaning Acrylic Surfaces Cleaning solvents are toxic and flammable. Skin protection and eye protection are required. Additionally, adequate ventilation and/or fresh air masks shall be used in all closed areas. Do not use any solvent other than aliphatic naphtha or Isopropyl alcohol to clean acrylic parts, as crazing may occur. Isopropyl alcohol can also craze acrylic if instructions are not carefully followed. Serials 2438 & subs: Do not allow isopropyl alcohol to contact fuel quantity sensor dial or cracking and crazing will occur. Serials 3026 & subs w/ Ice Protection and Perspective Avionics: Do not allow acetone to contact glycol quantity sensor dial or cracking and crazing will occur. If sealant is to be applied, use cleaning solvent only on portions of acrylic parts necessary to facilitate a proper sealing procedure. (1) Materials (a) Solvents Isopropyl Alcohol 99% or higher purity Aliphatic Naptha TT-N-95 Type II Acrylic Polish and Sealant SP-PL16 LP Aero Plastics Polish exterior window surface. 210 Plastic Cleaner And Polish SP-210A LP Aero Plastics Polish interior window surface. Miscellaneous Bristle Brush (non-nylon, non-metallic) Solvent Dispensers (polyethylene squirt bottle) Cotton cloth Cotton Gloves (clean, white, lint Free) Protective Gloves (neoprene rubber) - Clean up. - Dispense solvents. - Surface - Handle cleaned surfaces. - Protect hands from chemicals. Page 6 15 Dec 2014
Goggles - Protect eyes from chemicals. (2) Cleaning (a) Fold clean lint-free cloths in such a manner as to eliminate raw edges to reduce the possibility of lint contaminating the surface to be cleaned. Dampen one cloth with cleaning solvent from polyethylene squirt bottle. The cloth should not be saturated to a point where solvent drips. Never pour or spray cleaning solvent on aircraft structure because it will run back between structural layers, then run back out again after the cleaning operations are completed, bringing contamination to surfaces previously cleaned. (c) Thoroughly clean small areas at a time. Wipe area dry with a clean, dry, lint-free cloth. Do not allow solvent to air dry as a residue will remain on the surface, contaminating a following process. After thoroughly cleaning surfaces to be sealed, personnel should wear clean white gloves to prevent contaminating the surfaces to be sealed. If contamination occurs, surfaces shall be recleaned. If sealant is to be applied, always clean an area wider than the width of finally applied sealant. ow acrylic surfaces to completely dry, without contaminants, prior to sealing. (d) Continue cleaning until no discoloration is evident on the drying cloth. Page 7 15 Jun 2010
D. Solvent Cleaning Painted or Primed Surfaces for Placard Application Cleaning solvents are toxic and flammable. Skin protection and eye protection are required. Additionally, adequate ventilation and/or fresh air masks shall be used in all closed areas. (1) Materials (a) Solvents Isopropyl Alcohol 99% or higher purity Miscellaneous Solvent Dispensers (polyethylene squirt bottle) - Dispense solvents. Cotton cloth Cotton Gloves Protective Gloves (neoprene rubber) - Surface - Handle cleaned surfaces. - Protect hands from chemicals. Goggles - Protect eyes from chemicals. (2) Cleaning (a) Fold clean lint-free cloths in such a manner as to eliminate raw edges to reduce the possibility of lint contaminating the surface to be cleaned. Dampen one cloth with cleaning solvent from polyethylene squirt bottle. The cloth should not be saturated to a point where solvent drips. Never pour or spray cleaning solvent on aircraft structure because it will run back between structural layers, then run back out again after the cleaning operations are completed, bringing contamination to surfaces previously cleaned. (c) Thoroughly clean small areas at a time. Wipe area dry with a clean, dry, lint-free cloth. Do not allow solvent to air dry as a residue will remain on the surface, contaminating a following process. After thoroughly cleaning surfaces to be sealed, personnel should wear clean white gloves to prevent contaminating the surfaces to be sealed. If contamination occurs, surfaces shall be recleaned. (d) Continue cleaning until no discoloration is evident on the drying cloth. Page 8 15 Dec 2014