Silver-gray wet spots appear on the surface of the aluminum profile, and the aluminum alloy profile fades or disappears with the increase of the intensity of oxidation and alkali washing.
Causes of watermarks on the surface of aluminum profiles:
The surface of the aluminum profile is partially exposed to water and rain, and penetrates into the aluminum matrix through the tiny pores of the quenched oxide layer on the surface of the profile to form bayerite, which will become bright and light with the length of time the water stays. Corrosion spots will develop.
Watermark removal method on the surface of aluminum profiles:
The water-stained aluminum profiles should be wiped dry as soon as possible, and must be wiped dry before aging. If conditions permit, the alkali cleaning time and oxide film thickness should be appropriately increased.
As long as the oil stains and water stains are wiped clean before the dust-free aging of the aluminum profile, there will be no oil marks and watermarks. The key is to cultivate good operating habits and quality awareness, nothing else. There have been low-level quality accidents where oily paper was used as a profile liner to be covered with oil marks after self-effect.