导电涂层的修理REPAIR OF CONDUCTIVE COATINGS
1. INTRODUCTION 介绍
A. The data in this subject comes from Boeing Process Specification BAC5837 for preparation of exterior plastic surfaces for paint, and BAC5639 for application of BMS 10-21 conductive (anti-static) coating. Access to the Boeing Process Specifications is available.
本主题中的数据来自波音公司，用于油漆外部塑料表面制备的工艺规范BAC5837和用于BMS 10-21导电（防静电）涂层应用的工艺规范BAC5639。可访问波音工艺规范。
B. The data is general. It is not about all situations or specific installations. Use this data as a guide to help you write minimum standards.
数据是通用的。它不是关于所有情况或特定的安装。使用这些数据作为指导，帮助您制定最低标准。
C. Refer to SOPM 20-00-00 for a list of all the vendor names and addresses.
有关所有供应商名称和地址的列表，请参阅SOPM 20-00-00。
2. EQUIPMENT 设备
NOTE: Equivalent substitutes can be used.
注：可以使用等效的替代品。
A. Brush or spray equipment.
刷或喷涂设备。
B. Controlled heat source up to 170°F (77°C) to cure the coating, unless you use the room temperature cure.
除非使用室温固化，否则可控制高达170°F（77°C）的热源来固化涂层。
C. Resistivity Measurements:
电阻率测量：
NOTE: You can use any of these three methods to measure the resistivity of the coating.
注：您可以使用这三种方法中的任何一种来测量涂层的电阻率。
(1) Square Method
方形法
(a) Ohmmeter that can measure 100 megohm resistance
可测量100兆欧电阻的欧姆表
(b) Tape, flexible copper — Scotch X-1181, V76381
柔性铜带-Scotch X-1181、V76381
(2) ST895A-3 Probe Test Method
ST895A-3探针测试方法
(a) Ohmmeter that can measure 100 megohm resistance
可测量100兆欧电阻的欧姆表
(b) Probe ST895A-3
(3) 65C20346-1 Method
(a) Model 1 Meter: 65C20346-1
(b) Model 2 Meter: See BAC5639 PSD 6-14 par. 12.Z.c
3. MATERIALS 材料
NOTE: Equivalent substitutes can be used.
注：可以使用等效的替代品。
A. Solvents (SOPM 20-60-01)
溶剂（SOPM 20-60-01）
(1) Cleaning solvent, presealing: BMS 11-7
清洗溶剂，预密封：BMS 11-7
(2) Naphtha
石脑油
(a) Petroleum aliphatic: TT-N-95, Type 2
脂族石油：TT-N-95，类型2
(b) Mineral spirits: TT-T-291
矿物油：TT-T-291
(c) Dry cleaning solvent: P-D-680, Type 1
干洗溶剂：P-D-680，类型1
(3) Reducer: 66-C-22, V06367
还原剂：66-c-22，V06367
(4) Thinner: TR-15, V98502
稀释剂：TR-15，V98502
(5) Thinner: 020-707, V85570
稀释剂：020-707，V85570
B. Primer: BMS 10-79, Type 3
底漆：BMS 10-79，类型3
C. Conductive coating (SOPM 20-60-02)
导电涂层（SOPM 20-60-02）
(1) Anti-static coating: BMS 10-21, Type 3
防静电涂层：BMS 10-21，类型3
(a) PRC-DeSoto (V85570) System
1) Base: 528X310
2) Curing Solution: 910X464
(b) Akzo Nobel (V3EDW5) System
1) Base: 10-P2-3
2) Curing Solution: EC-110
(2) Anti-static coating: BMS 10-21, Type 4
(a) PRC-DeSoto (V85570) System
1) Base: CA 7870
2) Curing Solution: 910X464
D. Surfacers and fillers material as necessary, as specified in Table 1.
表1中规定的必要的表面活性剂和填料。
E. Miscellaneous 杂项
(1) Tack rags 粘布
(a) C-60, Chemical Cloth Co.
(b) SSF – #5132, Hyuk Sung Industry
4. SURFACE PREPARATION 表面处理
A. Solvent clean the surface as specified in SOPM 20-30-03.
按照SOPM 20-30-03的规定，用溶剂清洁表面。
B. Sand the area to be repaired to remove paint or primer and old conductive coating with 150 grit or finer abrasive cloth or paper.
用150粒度或更细的砂布或砂纸打磨待修复区域，以去除油漆或底漆以及旧的导电涂层。
C. Wipe off the sanding dust with a clean cloth that is wet with solvent.
用蘸有溶剂的干净布擦拭砂屑。
CAUTION： PINHOLE FILLERS ARE RECOMMENDED ONLY TO FILL SMALL SURFACE DEFECTS LOCALLY AND NOT AS A SMOOTHING MATERIAL. A CONTINUOUS LAYER OF FILLER MATERIAL WILL NOT MAKE A GOOD BOND FOR THE COATING.
注意：针孔填充物只建议用于局部填充小的表面缺陷，而不是用作平滑材料。连续的填充材料层将不能为涂层形成良好的结合。
D. If the surface to be coated is a decorative surface, fill pinholes in the base material with a material given in Table 1. If the surface is not decorative, it is not necessary to fill pinholes.
如果要涂覆的表面是装饰性表面，则用表1中给出的材料填充基材中的针孔。如果表面没有装饰性，就没有必要填充针孔。
E. Mask off all areas not to get the conductive coating.
遮盖所有区域，以免沾上导电涂层。
5. PREPARATION OF CONDUCTIVE COATING 导电涂层的制备
A. Shake the base material on a paint shaker before you mix in the curing solution (activator).
在混合固化溶液（活化剂）之前，在油漆摇壶上摇动基材。
B. Add the curing solution to the base material as shown in Table 2, or by the manufacturer’s instructions. Identify the container with the date and time it was mixed, and when the pot life will end.
如表2所示或按照制造商的说明将固化溶液添加到基材中。用混合时的日期和时间以及保质期结束的时间来标识容器。
C. Let the mixture stand a minimum of 30 minutes before you use it. Put a cover on the container to prevent contamination of the mixture and evaporation of the solvent.
使用前，让混合物静置至少30分钟。在容器上盖上盖子，防止混合物受到污染和溶剂蒸发。
6. APPLICATION OF CONDUCTIVE COATING 导电涂层的涂敷
A. Apply the coatings in a temperature range of 40-100°F (4-38°C).
在40-100°F（4-38°C）的温度范围内涂敷涂层。
B. For spray application, apply BMS 10-21 coatings to these dry film thicknesses:
对于喷涂，将BMS 10-21涂层涂覆到以下干膜厚度：
(1) BMS 10-21, Type 4 coating thickness: 0.6-1.0 mil (0.0006-0.0010 inch)
BMS 10-21，类型4涂层厚度：0.6-1.0密耳（0.0006-0.0010英寸）
(2) BMS 10-21, Type 3 coating thickness: 0.4-0.8 mil (0.0004-0.0008 inch)
BMS 10-22，类型3涂层厚度，0.4-0.8密耳（0.0004-0.0008英寸）
C. To monitor the film thickness, apply the coating also to a metal panel attached to the plastic part and measure the thickness on the panel after it is dry, or measure the coating on installed fasteners or inserts. Measure the thickness with a non-destructive test instrument with an accuracy of ± 0.1 mil (0.0001 inch).
为了监测膜厚度，还将涂层涂覆到连接到塑料部件的金属板上，并在板干燥后测量板上的厚度，或测量已安装紧固件或插入件上的涂层。使用精度为±0.1密耳（0.0001英寸）的无损检测仪器测量厚度。
D. For brush application of small touch-up areas less that 4 square inches, apply BMS 10-21 coating to the area to be touched up. Brush apply the coating to get a continuous layer without runs, sags or wrinkles, that is flush with the adjacent (old) coating.
对于小于4平方英寸的小补漆区域的刷涂，在待补漆区域涂BMS 10-21涂层。刷涂涂层以获得一个连续的层，没有流动、下垂或褶皱，与相邻（旧）涂层齐平。
7. REAPPLICATION OF CONDUCTIVE COATING AFTER COMPOSITE REPAIR 复合材料修复后导电涂层的重新涂覆
A. Expose the old coating that was applied before the composite repair as follows:
暴露复合材料修复前涂覆的旧涂层，如下所示：
(1) Remove any overcoats applied over the old conductive coating. To do this, sand off the overcoat around the composite repair with abrasive paper or cloth. Do not sand through the old conductive coating.
去除旧导电涂层上的任何涂层。要执行此操作，请使用砂纸或布打磨掉复合材料修复件周围的外涂层。不要打磨旧的导电涂层。
(2) Expose the old conductive coating in an area that is 0.1-1.5 inches wide, all around the composite repair area.
将旧的导电涂层暴露在0.1-1.5英寸宽的区域，整个复合材料维修区域周围。
(3) Do not remove the old conductive coating. Keep the old conductive coating layer as continuous as possible. Keep the discontinuities to less than 15% of the total circumference, with not more than one discontinuity longer than one inch.
不要去除旧的导电涂层。尽可能保持旧的导电涂层的连续性。保持不连续性小于总周长的15%，不超过一个长度超过一英寸的不连续性。
B. If necessary, apply masks to all areas not to get the new coating. Be sure to keep the old conductive coating exposed a minimum width of 0.1 inch all around the composite repair, as was done in Paragraph 7.A.(2).
如有必要，遮盖住所有不要涂覆新涂层的区域。如第7.a.（2）段所述，确保复合材料修复周围的旧导电涂层至少暴露0.1英寸的宽度。
C. If the base surface or old conductive coating becomes dirty, prepare the base surface for a new coating, and expose more old conductive coating in an area that does not have contamination, as specified in Paragraph 7.A., unless the contamination is only particles. If the contamination is only particles, remove the particles with compressed air or a new tack rag.
如果基底表面或旧的导电涂层变脏，则根据第7.a.段的规定，为涂覆新涂层准备基底表面，并在没有污染的区域暴露更多的旧导电涂层，除非污染仅为颗粒。如果污染仅为颗粒，则用压缩空气或新的粘性抹布清除颗粒。
D. Apply a new conductive coating layer to the repaired composite surface and the exposed old conductive coating as quickly as possible, but no more than 72 hours after you prepared the repaired base surface in Paragraph 7.C.
尽快在修复后的复合材料表面和暴露的旧导电涂层上涂覆一层新的导电涂层，但不得超过第7.C段中修复后的基面72小时。
E. Cure the new conductive coating as specified in Paragraph 9.
按照第9段的规定对新的导电涂层进行固化。
(1) As an alternative to a minimum temperature of 70°F (21°C), BMS 10-21, Type 3, or 4 coatings can be air-dried for 20 minutes minimum at 40 90°F (5 32°C) before fastener installation.
作为最低温度70°F（21°C）的替代方案，在安装紧固件之前，BMS 10-21、3型或4型涂层可以在40°F（5 32°C）下至少风干20分钟。
(2) BMS 10-21, Type 3 coatings can be air-dried for 2 hours minimum at 40-90°F (5-32°C) before you measure resistivity.
BMS 10-21，3型涂层可在40-90°F (5-32°C)下至少风干2小时，然后再测量电阻率。
F. Install fasteners as specified by the overhaul instructions and BAC5117-13.
按照大修说明书和BAC5117-13的规定安装紧固件。
G. Measure the resistivity of the new conductive coating as specified in Paragraph 10., with specific tests in Paragraph 10.H. For BMS 10-21, Type 3 coatings, the resistance between the old layer and the new layer must not be more than 300 kilohms.
按照第10段的规定，通过第10.H段的具体测试，测量新导电涂层的电阻率。对于BMS 10-21，类型3涂层，旧层和新层之间的电阻不得超过300千欧姆。
H. If the overhaul instructions apply an overcoat to the new conductive coating, apply the overcoat within 24 hours.
如果大修说明在新的导电涂层上涂上一层外涂层，则应在24小时内涂上外涂层。
8. GROUNDING PROCEDURE 接地程序
A. Method 1 (countersinks covered with a mask)
方法1（有遮盖物的埋头孔）
(1) Carefully remove the mask and solvent clean the countersink (SOPM 20-30-03).
小心地取下遮盖物并用溶剂清洁埋头孔（SOPM 20-30-03）。
(2) Install the fasteners.
安装紧固件。
(3) Do a test of the fasteners as specified in BAC5117-13.
按照BAC5117-13的规定对紧固件进行测试。
B. Method 2 (panel without a mask, with a grounding hole and a countersink drilled after coating)
方法2（无遮盖物的面板，带有接地孔和涂层后钻的埋头孔）
(1) Prepare the surface as specified in BAC5117-13.
按照BAC5117-13的规定准备表面。
(2) Install the fasteners.
安装紧固件。
(3) Do a test of the fasteners as specified in BAC5117-13.
按照BAC5117-13的规定对紧固件进行测试。
9. CURE OF CONDUCTIVE COATING 导电涂层的固化
A. Before you install fasteners, let the coated countersink areas dry a minimum of 20 minutes at 70-90°F (21-32°C).
在安装紧固件之前，应在 70-90°F (21-32°C) 温度下让涂有涂层的沉孔区干燥至少 20 分钟。
B. Before you make resistivity measurements or apply an overcoat, cure the coating as follows:
在进行电阻率测量或涂覆外涂层之前，按以下步骤固化涂层：
(1) Let the coating stand for 15 minutes minimum at 60-90°F (16-32°C) before you cure the coating. This “flash-off” time lets the solvent evaporate from the coating layer, to prevent defects such as bubbles, pinholes and craters during the heat cure.
在固化涂层之前，让涂层在 16-32°C (60-90°F) 温度下静置至少 15 分钟。这段 “闪离 “时间可让溶剂从涂层中蒸发，以防止在热固化过程中出现气泡、针孔和凹坑等缺陷。
(2) Heat cure at a temperature-time schedule along a curve defined by the values in Table 3. Do not cure higher than 160°F (71°C). Do not cure more than 2 hours at a temperature higher than 120°F (49°C):
按照表 3 所列值定义的温度-时间曲线进行热固化。固化温度不得高于 71°C (160°F)。在高于 49°C (120°F) 的温度下固化时间不要超过 2 小时：
(3) Let the coating cool for a minimum of 15 minutes at 60-90°F (16-32°C).
让涂层在 60-90°F (16-32°C) 下冷却至少 15 分钟。
(4) Optional, for Type 3 coating: As an alternative to the heat cure, you can air dry the coating for 2 hours at 60°F (16°C) minimum before you make resistivity measurements.
可选，用于 3 类涂层： 作为热固化的替代方法，可以在测量电阻率之前，在 60°F (16°C) 温度下风干涂层至少 2 小时。
C. If an overcoat is specified by the overhaul instructions, apply the overcoat within 24 hours. The minimum time to apply the overcoat is the same as the minimum time to measure resistivity.
如果大修说明中规定了涂层，则应在 24 小时内涂上涂层。涂覆涂层的最短时间与测量电阻率的最短时间相同。
10. RESISTIVITY MEASUREMENT OF CONDUCTIVE COATING 导电涂层的电阻率测量
A. Measure the resistivity after the conductive coating is fully cured and before you apply overcoats to the coating. If the overhaul instructions specify more than one layer of conductive coating, measure the resistivity of the complete coating, not each individual layer.
在导电涂层完全固化后和涂覆涂层之前测量电阻率。如果大修说明规定的导电涂层不止一层，则应测量整个涂层的电阻率，而不是每个单独涂层的电阻率。
B. For BMS 10-21, Type 4 coatings, you can use an ohmmeter with the copper tape procedure (Figure 2) or the ST895A-3 probe Figure 1.
对于 BMS 10-21，4 类涂层，可以使用欧姆表与铜带程序（图 2）或 ST895A-3 探头图 1。
C. For BMS 10-21, Type 3 coating, you can use an ohmmeter and the copper tape procedure (Figure 2), the ST895A-3 probe (Figure 1) or a special resistivity gage such as the 65C20346-1 unit (Figure 3).
对于 BMS 10-21 3 型涂层，可以使用欧姆表和铜带程序（图 2）、ST895A-3 探头（图 1）或 65C20346-1 装置等专用电阻率计（图 3）。
D. If the resistance of BMS 10-21, Type 4 coating is between 1 and 100 megohms per square (a square of any dimension), or if the resistance of BMS 10-21, Type 3 coating is not more than 300 kilohms per square, the conductive coating is satisfactory and you can apply the overcoat as necessary, as specified in Paragraph 11. below.
如果 BMS 10-21, 4 型涂层的电阻在每平方（任意尺寸的正方形）1 到 100 兆欧之间，或者如果 BMS 10-21,3 型涂层的电阻不超过每平方 300 千欧，则导电涂层令人满意，您可以按照下文第 11.段规定的，在必要时涂覆外涂层。
E. If the resistance of BMS 10-21, Type 4 coating is more than 100 megohms per square (a square of any dimension),
如果 BMS 10-21,4 型涂层的电阻超过每平方 100 兆欧（任何尺寸的正方形）、
(1) Cure the coating at 140-160°F (60-71°C) for 60-70 minutes.
在 140-160°F (60-71°C) 下固化涂层 60-70 分钟。
(2) Measure the resistance again.
再次测量电阻。
(3) If the resistance is not between 1 and 100 megohms per square, remove the coating and try again as specified in Paragraph 10.F.
如果电阻值不在每平方 1 到 100 兆欧之间，则清除涂层，然后按照第 10.F 段规定的方法再试一次。
F. If the resistance of BMS 10-21, Type 4 coating is less than 1 megohm per square (a square of any dimension):
如果 BMS 10-21 4 型涂层的电阻小于每平方 1 兆欧（任何尺寸的正方形）：
(1) Remove the coating down to the bare surface with 240 grit or finer abrasive paper. Do not sand down into the composite surface.
用 240 号砂纸或更细的砂纸将涂层打磨至裸露表面。不要打磨到复合材料表面。
(2) Solvent clean as specified in SOPM 20-30-03 or wipe with tack rags.
按照 SOPM 20-30-03 规定的溶剂清洗或用粘性抹布擦拭。
(3) Apply the conductive coating again as specified in Paragraph 6.
按照第 6 段规定的方法再次涂上导电涂层。
(4) Cure the coating as specified in Paragraph 9.
按第 9 段规定的方法固化涂层。
(5) Measure the resistance again as specified in Paragraph 10.A. and Paragraph 10.B.
按第 10.A 和 10.B 段的规定再次测量电阻。
G. If the resistance of BMS 10-21 Type 3 coating is more than 300 kilohms per square (a square of any dimension):
如 BMS 10-21 3 型涂层的电阻超过每平方 300 千欧（任何尺寸的正方形）：
(1) Sand the area with 240 grit or finer abrasive paper. Do not sand through the coating.
用 240 号砂纸或更细的砂纸打磨该区域。不要打磨穿透涂层。
(2) Solvent clean as specified in SOPM 20-30-03.
按照 SOPM 20-30-03 规定的溶剂清洗。
(3) Apply the conductive coating again as specified in Paragraph 6.
按照第 6 段规定的要求再次涂上导电涂层。
(4) Cure the coating as specified in Paragraph 9.
按第 9 段规定的方法固化涂层。
(5) Measure the resistance again as specified in Paragraph 10.A. and Paragraph 10.C.
按第 10.A 段和第 10.C 段的规定再次测量电阻。
(6) Do not let waxed papers touch the coating during transportation, storage, etc.
在运输、储存等过程中，不要让蜡纸接触涂层。
H. For new conductive coating applied after composite repair, measure the resistance by one of the methods shown, as applicable. Any one test method is sufficient; it is not necessary to use all methods.
对于复合材料修理后使用的新导电涂层，视情况使用所示方法之一测量电阻。任何一种测试方法均可，不必使用所有方法。
(1) Test Method 1: Between old and new coatings
测试方法 1：新旧涂层之间
(a) Put the probes directly against the conductive coating. Put one probe on the new coating and put the other on the old coating.
将探针直接放在导电涂层上。将一个探头放在新涂层上，另一个探头放在旧涂层上。
(b) If the old coating has an overcoat or other surface finish, remove a sufficient area of the overcoat to let the probes touch the conductive coating. Or carefully push the probes through the overcoat to touch the conductive coating.
如果旧涂层有涂层或其他表面处理，则去除足够面积的涂层，让探针接触导电涂层。或者小心地将探针穿过涂层，接触导电涂层。
(c) Make sure the resistance is 300 kilohms or less.
确保电阻等于或小于 300 千欧。
(d) If you removed the finish from the part to do this test, refinish the part as specified by the overhaul instructions within 7 days after you removed the original finish.
如果为进行此测试而去掉了零件的表面涂层，则应在去掉原表面涂层后的 7 天内按照大修说明规定的方法对零件进行重新处理。
(2) Test Method 2: Between the old coating in a fastener countersink and the new coating
测试方法 2：紧固件沉孔中的旧涂层与新涂层之间
(a) Put one probe directly against the new coating. Put the other probe directly against the old coating in a fastener countersink.
将一个探针直接放在新涂层上。将另一个探针直接放在紧固件沉孔中的旧涂层上。
(b) Make sure the resistance is 300 kilohms or less.
确保电阻等于或小于 300 千欧。
(3) Test Method 3: Between an installed fastener and the new coating
测试方法 3：已安装的紧固件与新涂层之间
(a) Put one probe directly against the new coating. Put the other probe directly against a fastener installed in the old coating.
将一个探针直接放在新涂层上。将另一个探头直接对准安装在旧涂层中的紧固件。
(b) Measure the resistance as specified in BAC5117-13.
按 BAC5117-13 规定的方法测量电阻。
(c) Make sure the resistance is 300 kilohms or less.
确保电阻等于或小于 300 千欧。
(d) The new coating is acceptable if the resistance is 300 kilohms or less. But the new coating is not to be rejected unless the resistance is 300 kilohms or less when measured by Test Method 1 (Paragraph 10.H.(1)) or Test Method 2 (Paragraph 10.H.(2)).
如果电阻为 300 千欧或更小，则新涂层可以接受。但除非按测试方法 1（第 10.H.(1)段）或测试方法 2（第 10.H.(2)段）测量的电阻为 300 千欧或更小，否则不得拒收新涂层。
11. APPLICATION OF OVERCOAT TO CONDUCTIVE COATING 导电涂层的覆涂
A. Mask the Countersinks for Electrical Bonding Fasteners
遮盖电气接合紧固件的沉孔
(1) Use this procedure to mask the anti-static coating of the countersinks for the electrical bonding fasteners when a different coating will be applied on the anti-static coating.
当防静电涂层上将涂上不同的涂层时，使用本程序遮盖电气连接紧固件沉孔的防静电涂层。
(2) You have two alternatives, as shown in Figure 4:
如图 4 所示，您有两种选择：
(a) Mask the countersinks and extend the mask 0.75-0.85 inch out from the edge of the hole, or
遮盖沉孔，并将遮盖物从孔边缘向外延伸 0.75-0.85 英寸，或
(b) If you know the size of the fasteners that will be installed, extend the mask 0.125-0.750 inch from the edge of the fastener or washer to be installed.
如果知道将要安装的紧固件的尺寸，则将遮盖物从将要安装的紧固件或垫圈边缘向外延伸 0.125-0.750 英寸。
B. Surfaces to be coated with enamel within 24 hours:
需在 24 小时内涂刷瓷漆的表面：
(1) Immediately before you apply the enamel, wipe the surface to be coated with a clean cheesecloth wet with naphtha.
在涂瓷漆之前，立即用石脑油浸湿的干净抹布擦拭待涂表面。
(2) Wipe the surfaces with a clean dry cheesecloth before the naphtha dries.
在石脑油干之前，用干净的干抹布擦拭表面。
(3) Apply and cure enamel as specified by the overhaul instructions.
按照大修说明书规定的方法涂抹和固化瓷漆。
C. Surfaces not to be coated with enamel in 24 hours:
24 小时内不涂刷瓷漆的表面：
(1) Immediately before you apply the primer, wipe the surfaces with a clean cheesecloth wet with naphtha.
在涂刷底漆前，立即用干净的抹布沾石脑油擦拭表面。
(2) Wipe the surfaces with a clean dry cheesecloth before the naphtha dries.
在石脑油干之前，用干净的干抹布擦拭表面。
(3) Apply and cure BMS 10-79, Type 2 or 3 primer within 24 hours from the time the conductive coating was applied. A full cure of the conductive coating is not necessary for the masked areas, such as the countersinks around holes for grounded fasteners.
在导电涂层涂抹后 24 小时内涂抹并固化 BMS 10-79、2 类或 3 类底漆。对于遮蔽区域，如接地紧固件孔周围的沉孔，无需完全固化导电涂层。
(4) Reactivate the primed surface immediately before you overcoat with enamel.
在涂覆瓷漆之前，应立即重新激活涂过底漆的表面。
(5) If there are pinholes, apply Static Conditioner 28-C-1 only to these areas.
如果有针孔，只在这些区域涂上静电防护剂 28-C-1。
(6) Apply and cure the enamel as specified by overhaul instructions.
按照大修说明规定的方法涂抹和固化瓷漆。
