2-6. CLEANING

TM 9-6115-604-34 NAVFAC P-8-633-34 2-6. CLEANING. Components may be cleaned with low pressure compressed air, then wiped dean with a dry, lint-free cloth. Components may also be cleaned with a cloth dampened in dry cleaning solvent P-D-680, Type II, or equivalent. 2-7. WlRING Tag all wires and cables during removal procedures for correct identification during replacement procedures. Before a part is unsoldered, note the position of the leads. If the part has several leads, tag each of the leads before unsoldering any of them. If wiring must be replaced, use leads of the same length and gage. Never use replacement wire with a higher gage number (smaller diameter). WARNING To avoid Injury to personnel, do not breathe fumes generated by soldering. Remove rings and watches while soldering. Eye protection is required to avoid Injury to personnel. 2-8. SOLDERING. On printed circuit boards, use a pencil-type soldering iron with a 25-watt maximum heating capacity. Make well-soldered connections, using no more solder than is necessary. Do not allow drops of solder to fall into the unit. Do not allow a soldering iron to come into contact with insulation or other parts that may be damaged by excessive heat. Do not disturb the setting of any uncalibrated control without first determining its proper setting. Repeat prior to reenergizing the equipment. WARNING Welding operations produce heat, highly toxic fumes, and Injurious radiation, metal slag, and airborne particles. Welding with goggles, the proper tinted lenses, apron or jacket, and welders gloves are required to avoid Injury to personnel. 2-9. WELDING. Proper preparation is an important factor in welding. Edges to be joined must be dean. Necessary arrangements for holding parts in proper alignment during welding should be made. Oil, grease, paint, or foreign matter of any kind must be removed. With edges properly prepared for welding, steps shall be taken to make certain that the finished job will be in correct alignment 2-10. EXPANSION PLUG REPLACEMENT. a. Drive a tapered punch through the center of the defective expansion plug and use the punch to pry out the plug. b. Clean the hole thoroughly using a hand wire brush to remove any rust or scale. c. Coat the outer diameter of the new expansion plug with sealant MIL-S45180. d. Using a bushing driver that fits the inner and outer diameters of the expansion plug, drive the plug into the hole until it is recessed approximately 0.062 inch (1 .57mm). 2-11. HEUCAL INSERT REPLACEMENT. a. Using a sharp scratch-awl, lift the end of the insert, and remove it using needle nose pliers (A, Figure 2-1). b. Using special insert tap of the proper size as listed in MS-33537 (Standard Dimensions for Insert, Screw Thread, Helical Coil, Coarse and Fine Thread), repair any thread damage caused by removal (B, Figure 2-1). c. Using the installing tool, screw in the new insert to a depth of 3/4 to 1 1/2 threads below the edge of the hole (C, Figure 2-1). d. Using the break off tool, remove the driving tang form the insert (D, Figure 2-1). 2-19