Apply using a standard undercoating gun .

喷涂时可使用一种标准底漆枪。

Undercoating production line for cabinet of farm truck .

农用车驾驶室底面漆生产线。

Most mirrors require an undercoating of copper to conserve the more expensive silver .

大多数镜子需要铜底漆保护较昂贵的银牌。