Sealing Etched Surfaces: Lacquer, Wax and Passivation
蚀刻面的封护：清漆、蜡与钝化
标签：封护, BTA, 微晶蜡, 防变色, 钝化
蚀刻凹槽藏酸藏盐，封护前必须彻底清洗：5% 草酸退膜 → 流水刷洗 → 去离子水煮 5 min 提盐 → 无水乙醇脱水。室内件用 1–3% BTA（苯并三氮唑）乙醇液浸 30 min 形成铜络合膜，再热涂微晶蜡（50 ℃）；户外件选双组分 PU 清漆喷涂两道、干膜 60 μm 以上。填黑漆的蚀字件忌厚漆外溢，先点灌再平刮。封护层每年检查一次，出现白点即膜下起锈，需局部退膜重封。
Etched grooves trap acid and salts—clean fully before sealing: strip resist in 5% oxalic acid, scrub under running water, boil 5 min in deionised water to extract salts, dehydrate in ethanol. Indoor pieces: inhibit 30 min in 1–3% BTA ethanol to grow the copper-complex film, then hot-wax with microcrystalline wax at 50 °C. Outdoor: two coats of 2K polyurethane to 60 μm dry film. For ink-filled lettering, spot-fill then squeegee flat—never over-spread. Inspect yearly; white bloom means rust under film—strip locally and reseal.