Aluminum alloy. Surface treatment. Extruded with film release. Then. On the falling chemical film. Carbon steel parts. Hydrochloric acid. After treatment. Phosphate coating. It will not be embroidered. It can prevent rot
Premise must be sprayed with Sakura, but if not sprayed with Sakura, it can be painted with anticorrosive paint. Note that where there is anticorrosive paint can not be sprayed