Appendix 1
TRACERS
74. Indicator, Thymol Blue Reagent, MIL-T-17412 For detecting reverse voltage damage to wet-slug tantalum capacitors. Also used as a Nicad electrolyte indicator.
75. Desiccant, Bagged, MIL-D-3464, Grade A Absorbs moisture, lowers relative humidity when sealed in container.
76. Humidity Indicator, MS-20003 Used to determine that desiccant within a package is sufficiently active to maintain a relative humidity below that at which corrosion will occur.
77. Water, Distilled Used for cleaning in critical soldering operations.
78. Ammonium Hydroxide, Technical, O-A-451 Used to assist in dissolving indicator, Thymol Blue Reagent, A-A-59282.
79. Glass Beads, MIL-G-9954 Used as abrasive in handheld tool in blast cleaning cabinet.
80. Silver Nitrate, A-A-59282 Used to identify magnesium metal.
81. Silver Nitrate, Solution, MIL-W-535 Used to identify magnesium metal.
Appendix 2 APPENDIX 2. SPECIFIC CONSUMABLE MATERIALS FOR CLEANING AND
CORROSION PREVENTION AND CONTROL
2-1. INTRODUCTION AND SCOPE.
This appendix supplements Appendix 1 by providing a more detailed listing of selected products by product numbers (P/N) and manufacturer(s) of acceptable consumable materials for avionics cleaning and corrosion prevention and control. Table 2-1 provides product numbers and manufacturer’s name. Table 2-2 provides a listing of the manufacturers and addresses of their main plants.
Table Grouping Page(s) 2-1 Cleaning Compounds…………………………………………1 Corrosion Preventive Compounds………………………….1-2 Sealants……………………………………………………..2-3 2-1 2-1 TABLE 2-1. AVIONICS CLEANING AND CORROSION REMOVAL CONSUMABLE
MATERIALS ITEM NO. PRODUCT TYPE MANUFACTURER’S
DESIGNATION CLEANING COMPOUND, MIL-PRF-85570 9 Type II Leeder 1140-F 9 Type II 8505 9 Type II Calla 855 9 Type II Aerowash NV 9 Type II AC-17 8 9 Type II ED-4 10 9 Type II EZE-445 9 Type II MA-102 9 Type II CeeBee R-682 9 Type II 8002-2-SD 9 Type II Octagon 855702 9 Type II LD-38 9 Type II PENN AIR M5572B 9 Type II 93-1 9 Type II Turco 6692 CORROSION PREVENTIVE COMPOUND, MIL-PRF-81309, Class 1 (Bulk), Class 2 (Aerosol) 20 Type III 2080-MLCO 20 Type III So-Sure 0964-000 20 Type III LPS-814A 20 Type III 22028C2-3 20 Type III Ardrox 3205 Aerosol
Appendix 2 ITEM NO. PRODUCT TYPE MANUFACTURER’S
DESIGNATION 20 Type III CRC 3-36 20 Type III ACF-50 Aerosol 21 Type II Class 1 Alox 2028C 21 Type II Class 1 Aidchim Alox 2080 21 Type II Class 1 2028 BC-BULK 21 Type II Class 1 Nox Rust 212 21 Type II Class 1 2775 21 Type II Class 1 So-Sure 813 21 Type II Class 1 LPS-813 Bulk 21 Type II Class 1 Octoil 5068 21 Type II Class 1 Omni 4150A 21 Type II Class 1 97-SX092 21 Type II Class 1 22018CM-Bulk 21 Type II Class 1 Ardrox 3204 21 Type II Class 1 BATCO Rust Preventive 21 Type II Class 1 706 P.D.R.P. Bulk 21 Type II Class 1 D-5026 Bulk 21 Type II Class 1 Ardrox 3204 Aerosol 21 Type II Class 2 2028-BCCO Bulk 21 Type II Class 2 So-Sure 0954-000 21 Type II Class 2 LPS-813A 21 Type II Class 2 706 P.D.R.P 21 Type II Class 2 22028C2 CORROSION PREVENTIVE COMPOUND, MIL-PRF-16173 23 Grade 4 TECTYL 846 23 Grade 4 846-BC 23 Grade 4 Braycote 194 23 Grade 4 CONVOY 734 23 Grade 4 Nox-Rust X-110 23 Grade 4 F & L 5846 23 Grade 4 Steelgard MS-31 23 Grade 4 Poly Oleum 5000 23 Grade 4 ST 1846 23 Grade 4 No-Rust X-10 SEALANTS MIL-PRF-81733, Type I (Brush Application), Type II (Spatula Application) NOTE: Dash number following Type gives working time of the sealant in hours.
34 Type I-1/2 P/S 870 A-1/2 34 Type I-1/2 PR 1440G A-1/2 34 Type I-2 P/S 870 A-2 34 Type I-2 PR 1440G A-2 34 Type II-1/2 P/S 870 B-1/2 34 Type II-1/2 PR 1440G B-1/2
Appendix 2 ITEM NO. PRODUCT TYPE MANUFACTURER’S
DESIGNATION 34 Type II-2 P/S 870 B-2 34 Type II-2 PR 1440G B-2 34 Type II-2 PR 1436G B-2 34 Type II-4 P/S 870 B-4 34 Type II-4 PR 1440G B-4 SEALANTS SAE-AMS-S-8802, Class A (Brush Application), Class B (Spatula Application) NOTE: Dash number following Class gives working time of the sealant in hours.
36 Class A-1/2 PR-1422 36 Class A-2 36 Class B-1/2 36 Class B-1 36 Class B-2 36 Class B-2 BR 4005 36 Class B-1/2 FR 1072 36 Class B-2 36 Class A-1/2 CS-3204 36 Class A-1 36 Class A-2 36 Class B-1/2 36 Class B-1 36 Class B-2 36 Class B-1 WS-8020 36 Class B-2 36 Class B-4 36 Class B-1/2 MC-236 36 Class B-1 36 Class B-2 36 Class B-2 PR-1440 36 Class A-1/2 PR-1440 36 Class A-1 PR-1440 36 Class A-2 Pro-Seal 890 36 Class A-2 PR-1440 36 Class B-1/2 Pro-Seal 890 36 Class B-1/2 PR-1440 36 Class B-1 PR-1440 36 Class B-2 Pro-Seal 890 36 Class B-2 PR-1440 36 Class B-4 Pro-Seal 890 36 Class B-4 PR-1440
Appendix 3 APPENDIX 3. DEFINITION OF TERMS Acetic Acid An organic acid that can form when a microorganism (acetobacteraceti) reacts with ethyl alcohol in the presence of oxygen. Characteristic of vinegar.
Acidic Acid forming or having acid characteristics.
Active Metal A metal ready to corrode or being corroded.
Additive A compound added for a particular purpose. For example, additives in fuel and lubricants can prevent corrosion, gum formation, varnishing, sludge formation, and knocking.
Aerobic A process which is incapable of occurring in the absence of oxygen.
Alkaline Having a pH greater than 7.
Alloy A combination of two or more metals.
Anaerobic A process which is capable of occurring in the absence of oxygen.
Anion A negatively charged ion of an electrolyte which migrates toward the anode. The chloride in sea water is an anion.
Anode The electrode of a corrosion cell at which oxidation or corrosion occurs. It may be a small area on the surface of a metal or alloy, such as that where a pit develops, or it may be the more active metal in a cell composed of two dissimilar metals, (i.e., the one with the greater tendency to go into solution). The corrosion process involves the change of metal atoms into actions with a liberation of electrons that migrate through the metal to the cathode of the cell.
Anodize Application of a protective oxide film on a metal (such as aluminum) through an electrolytic process. This layer provides protection from corrosion and is a good base for paint.
Aqueous Made from, with, or by water.
Appendix 3 Austenitic A term applied to that condition of iron associated with a change in crystal structure that makes it nonmagnetic. This occurs with ordinary iron at an elevated temperature. When sufficient chromium and nickel are present, lead becomes austenitic (nonmagnetic) at atmospheric temperatures. This is the case with many stainless steels that combine about 18% chromium and 8% or more nickel.
Bilge The lowest point of an aircraft’s inner hull. This is the area where cable runs, wire bundles, and coaxial cables are routed, and lights and antennas are often mounted.
Capillary Action The action by which the surface of a liquid in contact with a solid is advanced or retarded (raised or lowered). This is caused by the relative attraction of the liquid molecules to each other (surface tension) and those of the solid. The wicking of fluid up a cloth is an example of capillary action.
Carbonize To convert into carbon residue, usually by high heat.
Cathode The less-active electrode of a corrosion cell, where the action of the corrosion current causes a reduction reaction.
Cation A positively charged ion of an electrolyte which migrates toward the cathode. Metal ions, such as iron or copper, are cations.
Caustic Embrittlement The result of the combined action of tensile stress and corrosion in an alkaline solution. This can occur in riveted lap joints where there is a concentration of an alkali solution.
Cell In the corrosion process, a cell is a source of an electrical current that is responsible for the corrosion. It consists of an anode and a cathode immersed in an electrolyte and electrically joined together. The anode and cathode may be separate metals or dissimilar areas on the same metal.
Chemical Conversion Coating A chemical treatment of a metal surface, such as aluminum or magnesium, which results in a protective (corrosion resistant) film on the metal’s surface. The coating also greatly enhances paint adhesion.
Chloride A compound of chlorine. Many varieties of this compound are present in seawater and contribute to making the seawater an electrolyte (electrical conductive).
Clear Water Colorless water containing no visible suspended particles.
Appendix 3 Compound Substances containing two or more elements.
Concentration Cell An electrolytic cell, consisting of an electrolyte and two electrodes of the same metal or alloy, that develops a difference in potential as a result of a difference in concentration of ions (most often metal ions) or oxygen at different points in the solution.
Conformal Coating A closely adhering moisture and gas barrier applied to circuit boards to prevent corrosion and breakdown of electrical insulation.
Corona A faint glow adjacent to the surface of an electrical conductor at high voltage.
Corrosion The deterioration of a substance (usually a metal) because of a reaction with its environment.
Corrosion Fatigue A reduction in the ability of a metal to withstand cyclic stress by its exposure to a corrosive environment.
Corrosion Rate The speed or rate of a corrosion attack expressed in material weight loss per unit of time.
Couple Two or more metals or alloys in electrical contact with each other. These usually act as the electrodes of a cell if they are immersed in an electrolyte.
Critical Avionics Components Miniature or microminiature circuits including the components, printed circuit boards, tunable coils, tuned circuits, and devices with gold- or silver-plated connectors or contacts.
Critical Humidity The relative humidity, under a specific set of conditions, at which a metal or an alloy will begin to corrode. In the presence of hygroscopic (moisture-absorptive) solids or corrosion products, the critical humidity will be lowered. For example, steel will not corrode if the relative humidity is less than 30 percent in a marine atmosphere.
Deionized Water Water which has had various minerals and inorganic materials removed by means of an ion exchange process.
Desiccant A drying agent which acts by absorbing moisture.
Appendix 3 Distilled Water Water which has various organic and inorganic materials removed by means of an evaporation and condensation (distillation) process.
Durability Ability of avionics equipment or components to function and sustain stress in field service for a specific period of time with economical maintenance. The durability is measured in terms of minimum acceptable failure free lifetime (MFL) and expected maximum lifetime (EML), including repairs.
Elastomer A synthetic material with elastic properties.
Electrode A metal or alloy that is in contact with an electrolyte and serves as the site where electricity passes in either direction between the electrolyte and metal. The current in the electrode itself is a flow of electrons, whereas, in the electrolyte ions carry electrical charges, and it is their orderly movement in solution which constitutes a flow of current in the electrolyte.
Electrolyte Any substance which, in solution or fused, exists as electrically charged ions that render the liquid capable of conducting a current. Soluble acids, bases, and salts, such as those in seawater, are electrolytes.
Element Substances which cannot be decomposed by ordinary chemical changes or made by these changes.
Embrittlement Severe loss of ductility of a metal alloy.
Emulsified One liquid dispersed throughout another liquid with which it will not mix to form a homogeneous solution.
Encapsulant The general term describing materials used to envelop or fill a void to prevent the entrance of moisture or fungus. Conformal coatings, fungus-proof coatings, and potting compounds are all forms of encapsulants.
Ester/Diester Oils Oils containing synthetic materials known as esters or diesters, which are chemically formed by the reaction of an alcohol and an acid. These synthetic oils can attack certain plastics and paints.
Exfoliation The breaking away of a material from its surface in flakes or layers. A thick layer-like growth of corrosion products.
Appendix 3 Expected Maximum Lifetime The expected maximum period of time over which an avionics system, subsystem, module, or component performs satisfactorily. This includes acceptable availability, operation, and support cost (specific number of repair cycles).
Fatigue Tendency of a material to fracture in a brittle manner under repeated cyclic stressing or load at stress or load levels below its tensile strength.
Faying Surface The common surface between mating surfaces of parts.
Fungus A group of celled organisms (eukaryotic) that get their nutrients by secreting enzymes that break down organic matter in the tissue of other living or dead organisms. They then absorb the resulting nutrients. Includes mold, mildews, smut, mushrooms, and some bacteria.
Galvanic Couple Two electrically connected dissimilar metal conductors (may be a single metal in alloy) immersed in an electrolyte.
Galvanic Series A list of metals and metal alloys arranged in an order of their relative electrical potentials for a given environment. The order of their arrangement in one list may be different in another environment.
Hydrogen Embrittlement Loss of ductility of a metal caused by the entrance or absorption of hydrogen ions.
Hygroscopic The property of readily absorbing and retaining moisture.
Inorganic Coating A coating composed of matter other than of plant or mineral origin (i.e., electroplating, chemical conversion coating, anodize, phosphate, or oxide, etc.).
Ion An electrically charged atom or group of atoms. The sign of the charge is positive in the case of cations and negative in the case of anions.
Malfunction The improper operation of a component or system.
Microbes Microscopic living plants or organisms such as germs, molds, bacteria, and fungi.
Mil A unit of length equal to one thousandth of an inch (0.001 inch).
Appendix 3 Minimum Failure Free Lifetime (MFL) The minimum period of time that an avionics system, subsystem, module, or component performs satisfactorily without failure.
Nitrates Compounds including certain combinations of nitrogen and oxygen. Present in many industrial pollutants.
Noble Metal A metal usually found as uncombined metal in nature. Platinum, gold, and silver are noble metals.
Noncritical Avionics Components Components such as tube sockets, mechanical devices, knobs, and hardware.
Non-Destructive Inspection A method used to check the soundness of a material or a part without diminishing the strength, value, quality, or serviceability of the part.
Organic Coating A coating composed of matter derived from living organisms or carbon-based compounds
(i.e., paint, plastic, grease, preservative).
Outgassing Emission of a gas during the cure or decomposition of organic material. Usually increases with a rise in temperature.
Passivation The process or processes that cause a metal to become inert in a given corrosive environment.
pH A measure of hydrogen ions in concentration of a solution (pH 7 is neutral; below 7 is acidic;
above 7 is basic or alkaline).
Phantom Gripe An intermittent malfunction or failure which cannot be verified, identified, or duplicated for corrective action.
Pitting A form of corrosion that develops in highly localized areas of a metal surface that is not attacked elsewhere to any great extent. This corrosion attack results in the development of cavities or pits.
Pits may vary from deep cavities of small diameter to relatively shallow depressions.
Plasticizer A chemical added to rubber or resins to impart flexibility.
Appendix 3 Polyethylene A thermal plastic (softens when heated) characterized by its high impact strength, high electrical resistively, nontoxicity, and combustibility. One of several plastics used in wire coating.
Potting Compound A rubber-like material, usually poured, which cures to a hard consistency and provides moisture and vibration resistance to the item.
Primer Coat The first coat of a protective paint system. Improves adhesion of the succeeding topcoat and usually contains a corrosion inhibitor.
Reduction Reaction Gain of electrons by a constituent of a chemical reaction.
Relative Humidity The ratio of the amount of water vapor in the air at a specific temperature to the maximum amount that the air could hold at that temperature, expressed as a percentage.
Reversion The situation wherein a cured material reverts toward its original pre-cured condition, (e.g., a cured potting compound that reverts to a sticky, liquid-like consistency).
Stress Force divided by cross-sectional area.
Symbols The following definitions apply to warnings, cautions, and notes found throughout this advisory circular (AC):
WARNING: An operation or maintenance procedure, practice, condition, statement, etc., which if not strictly observed, could result in injury to or death of personnel or long term (chronic) health hazards to personnel.
CAUTION: An operation or maintenance procedure, practice, condition, statement, etc., which if not strictly observed, could result in damage or destruction of equipment or loss of mission effectiveness.
NOTE: An operating procedure, practice, or condition, etc., which is essential to emphasize.
Tensile Strength Stress at which a material fails.
Total Environment The circumstances and conditions which surround and influence the equipment. The total environment includes manufacturing, handling, storage, shipping, mission, maintenance, and repair.
Appendix 3 Ultraviolet Light Light in a wavelength band ranging from the invisible wavelengths of about 4 nanometers (nm) to the border of the x-ray region at about 380 nm, just beyond the violet end of the visible spectrum.
Unacceptable Response A detrimental abnormality in system performance.
Undesirable Response A tolerated interruption of normal performance.
Wicking See Capillary Action.