Preliminary Requirements

Safety Requirements

WARNING

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

Procedure

1. SUBTASK 70-09-02-400-001 Procedure to Make a Mark Electrolytically

   
   CAUTION
   DO NOT ELECTROLYTICALLY ETCH ANODIZED SURFACES.

   1. General.

      1. Symbols are made with electrolysis which is confined to the area of the symbol with a stencil.

      2. This permanent method is sometimes used as a temporary method. It is not the same as electric arc scribing.

   2. Preparation.

      1. Make sure the parts are clean and all grease, scale, and oxide are removed. Use the applicable cleaning procedure specified in the Engine Manual for the part.

      2. Grit-blasted, peened, or porous steel surfaces must have a thin layer of a petroleum-type corrosion inhibitor from TASK 70-38-37-300-503 before the mark is made. This will prevent distortion of the mark and possible corrosion.

   3. How to make the mark.

      1. 

         CAUTION

         DO NOT USE A TOOL THAT HAS DAMAGE TO MAKE THE MARKS.

         UNLESS SPECIFIED DIFFERENTLY, MARKS MADE ELECTROLYTICALLY MUST BE SHALLOW ETCHED.

         MAKE SURE THE HAND MARKER HAS FULL INSULATION. THIS WILL PREVENT BURN DAMAGE TO THE PART.

         Make the mark on the part with only sufficient force to make the electrolyte touch the part.

      2. Use the applicable electrolyte and power supply (AC or DC) specified in Step.

      3. 

         CAUTION

         THE TOOL USED TO MAKE THE MARK AND THE PART MUST NOT MOVE DURING THE TIMED CYCLE.

         The mark will usually be made in two to three seconds (the time necessary will be found with use). If the mark is made for more than four to five seconds, it will usually cause early stencil deterioration. It will not increase the quality of the mark.

      4. After a mark is made on soft metals (for example, silver, zinc, and copper), do not make neutral immediately. Stop for a short time to let the mark become permanent.

   4. Preservation.

      1. Remove all remaining liquid electrolyte from the part.

      2. In less than three minutes after the mark is made, soak the part in a solution of 1 part of CoMat 01-222 ELECTROLYTIC MARKING CLEANING FLUID to 19 parts of water. Let the part soak for a minimum of two minutes.

         Alternatively, clean the part with CoMat 01-220 WIPING TISSUEs or, for ferrous metals, you can use CoMat 02-082 DISPOSABLE WIPING TISSUES saturated with CoMat 01-240 CLEANER.

      3. If a water-base cleaner is used, make sure the part is fully dry before you apply oil so that remaining corrosion does not get caught in the part.

      4. Apply a petroleum-type corrosion inhibitor to preserve the part. Refer to TASK 70-38-37-300-503. An alternative protection method is to use the procedure in SPM Task TASK 70-38-05-380-501.

2. SUBTASK 70-09-02-400-002 Specification Table for Electrolytic Marks

   Metals and Alloys			Circuit Power Supply		Electrolytes CoMat No.		Color of Etch		Notes
   Aluminum 99.7% Pure			AC Normal		06-077		Black		Let the color develop before it is cleaned.
   			DC Normal		06-077		White		Frequently used on shiny or polished surfaces
   Aluminum Alloys			AC Normal		06-077		Black		Let the color develop before it is cleaned.
   			DC Normal		06-077		White		Frequently used on shiny or polished surfaces
   Aluminum that contains 10% or more magnesium			DC Normal		06-077		White		Alloys that have a high proportion of magnesium can not have a color mark applied.
   Aluminum that contains 5% or more silicon			DC Normal		06-077		White		Alloys that have a high proportion of silicon can not have a color mark applied.
   Anodized Aluminum			DC Normal		06-077		White		Make the mark before it is anodized.
   Aluminum Bronze			DC Normal		06-076		Clear		80 to 90 percent Copper, 2 to 10 percent Aluminum, Iron and Tin.
   			AC		06-076		Black
   Aluminum Silicon Bronze			See Aluminum Bronze.
   Bronze, Phosphor			See Aluminum Bronze.
   Bronze			DC Normal		06-075, 06-076		Clear		The electrolyte will depend on the elemental composition.
   			AC		06-075, 06-076		Black
   Brass			See Bronze.
   Carbides
   	Boron- Bearing		AC		06-077		Black		-
   	Tantalum- Bearing		AC		06-077		Black		-
   	Titanium- Bearing		AC		06-077		Black		-
   	Tungsten- Bearing		AC		06-077		Black		-
   Cobalt Alloys, Stellites			DC Normal		06-075, 06-077		Clear		A grit blasted surface must have a thin layer of oil applied before the mark is made.
   			AC		06-075, 06-077		Black
   Copper and alloys			DC Normal		06-076		Clear		The electrolyte will depend on the metal composition.
   			AC		06-076		Black
   Discaloy			AC		06-075		Black		-
   Gold and alloys			DC Normal		06-075		Clear		-
   			AC		06-075		Black		-
   Hastelloys			AC		06-076, 06-075		Black		-
   Inconel			AC		06-075		Black		-
   Iron and alloys
   1. Iron (Pure)			AC		06-075, 06-077		Black		-
   2. Steels
   a)	Low carbon and mild		DC Normal		06-075, 06-077		Clear		Make the mark with an AC circuit or a DC normal circuit, for the necessary surface finish and result.
   			AC		06-075, 06-077		Black
   b)	Low alloy steels:
   	Machined		AC		06-075, 06-077		Black		Make the mark with an AC circuit or a DC normal circuit, for the necessary surface finish and result.
   	Polished		AC		06-075, 06-077		Black
   	Vapor blast, Sand blast		AC		06-075, 06-077		Black		Apply a thin layer of oil to the open structure surface before the mark is made.
   	Descaled		AC		06-075, 06-077		Black		-
   	Nitrided		AC		06-075, 06-077		Black		-
   	Carburized		AC		06-075, 06-077		Black		-
   c)	High alloy and tool steel		AC		06-075, 06-077		Black		-
   d)	Saw steel		AC		06-075, 06-077		Black		-
   e)	Stainless steel, 300 and 400 series		DC Normal		06-075, 06-077		Clear		The circuit used will depend on the necessary surface finish and result.
   			AC		06-075, 06-077		Black
   Monel Metals			DC Normal		06-075		Clear		The circuit used depends on the necessary surface finish and result.
   			AC		06-075		Black
   Nickel and alloys			AC		06-077, 06-076		Black		-
   Titanium and alloys			AC		06-075		Dark		-
   SUPPLEMENTAL COATINGS - ELECTROPLATE
   Chromium, Hard			AC or DC		06-077		Clear		No composite coating
   Copper electroplate on steel			AC		06-076, 06-075		Black		-
   Nickel (Electrolytic)			AC		06-077, 06-076		Black		Clear etch with DC normal circuit.
   Nickel (Electroless)			AC		06-077, 06-076		Black		-
   Silver plate			DC Normal		06-076, 06-075		Clear		Let it set before it is cleaned. The result of the etch will depend on the base metal and the composition of the composite coatings.
   			AC		06-076, 06-075		Black
   Phosphated steel			Nonconductive coating; cannot be electrolytically marked unless the coating is very thin. Refer to the first note shown below.
   NOTE All surfaces must be conductive to have an electrolytic mark made. Painted, lacquered, or enamelled surfaces are not conductive and cannot be electrolytically etched. Anodized aluminum (electrolytic or chemical) is not conductive and must have the mark made before it is anodized. Heavy phosphated steel is not conductive. Where more than one electrolyte is specified, the list is in the order of most-to-least preferred.