Answer:
Here are some ways of reducing water vapor and its harmful effects in the metallizing system:
1. Metallize parts as quickly as possible after basecoating. The longer parts are exposed to the atmosphere, the more water they will bring into the chamber with them.
2. Keep the chamber clean. Aluminum deposits are porous and will absorb lots of water.
3. Keep chamber closed and under vacuum unless loading or unloading parts.
4. Air-condition or dehumidify metallizing area.
5. Learn the proper use of your mechanical pump’s gas ballast.
6. Consider installing a cryogenic pump to trap water vapor. This is expensive but highly effective. It usually pays for itself with shorter cycle times and fewer bad parts.
Explanation:
Source: https://www.tungsten.com/tips/water-vapor-and-vacuum-metallizing/
