What is the discoloration and yellowing point in bronze doors?

I am honored to answer your questions!

It's very good upstairs. Let me add a few more points.

1. No matter how advanced the technology is, the copper door will change color sooner or later, just depending on the length of time and the severity of the situation. There is no copper door that will never change color. No matter how well you protect it, the metal will be oxidized.

2. Copper is a metal which is difficult to be oxidized, and its properties are relatively stable. So now bronze doors is more popular. But it is also beautiful. I think there are several reasons for the discoloration of copper doors:

① The reverse side of copper is not protected before chemical treatment. After the copper door is assembled, the copper material is oxidized and discolored from the back due to the untreated back of the copper plate and the influence of air.

(2) The copper plate is chemically treated, and the paint is not dried before spraying.

(3) The paint does not meet the requirements or the spraying is too thin.

④ Copper problem.

⑤ The external environment where the copper door is located is harsh.

I hope I can help you!