Dimethyl silicone oil (with a viscosity of 200 cSt) can be used on glass surfaces, and its applicability mainly depends on specific usage scenarios and needs. Here is an explanation from the aspects of characteristics, applicable scenarios, and precautions:

1. Core characteristics of 200 cSt dimethyl silicone oil

• Chemical stability: It is resistant to high and low temperatures (-50°C to over 200°C), oxidation, and ultraviolet rays, and is not prone to chemical reactions with glass.
• Hydrophobicity: It has low surface tension and can form a uniform hydrophobic film on the glass surface, reducing the adhesion of water and stains.
• Lubricity: It has good lubricating and release properties, reducing friction or adhesion.
• Transparency: It is inherently colorless and transparent; when applied evenly, it hardly affects the light transmittance of glass (avoid accumulation to prevent reduced transparency).

2. Typical application scenarios on glass surfaces

1. Release and anti-adhesion
   If glass is used as a mold (e.g., for casting resin, concrete, etc.) or needs to prevent adhesion of other materials (such as tape or glue), applying 200 cSt silicone oil can form an isolation film, facilitating subsequent demolding or removal of residues.
2. Waterproofing and anti-fouling
   The hydrophobic property of silicone oil can reduce water stain residues on glass surfaces (e.g., bathroom glass, car windows) and provide a certain anti-fog effect (requires even application to reduce water vapor condensation). However, its effect is weaker than that of professional anti-fog agents, and its durability is limited (easily damaged by friction or cleaning agents).
3. Lubrication and drag reduction
   Sliding parts of glass products (such as glass conduits, valves) can be coated with silicone oil for lubrication to reduce friction and wear; it can also be used in sealing/lubrication scenarios where glass contacts other materials (such as rubber, metal).
4. Temporary protective coating
   When storing or transporting glass for a short period, applying a thin layer of silicone oil can isolate dust and moisture, reducing the risk of scratches (note whether subsequent cleaning will be convenient).

3. Precautions

1. Adhesion and durability
   The adhesion between silicone oil and the glass surface is weak (mainly relying on physical spreading), so it is easy to fall off due to friction, wiping, or contact with solvents (such as alcohol, gasoline). It is not suitable for long-term exposure to high-friction or strong cleaning scenarios.
2. Impact on subsequent processing
   If the glass surface requires subsequent coating, bonding (e.g., with silicone glue or glass glue), or printing, residual silicone oil will seriously affect adhesion, leading to coating peeling or bonding failure. It must be thoroughly removed with solvents (such as toluene, xylene) in advance.
3. Usage method
   It is recommended to first clean the glass surface (to remove oil and dust), then evenly apply a thin layer of silicone oil with a cloth, sponge, or spray (avoid excessive accumulation to prevent reduced light transmittance or dust adhesion).

Summary

200 cSt dimethyl silicone oil can be used on glass surfaces, suitable for short-term waterproofing, anti-adhesion, lubrication, or temporary protection scenarios. However, it should be noted that its adhesion is limited, and it may affect subsequent processing (such as bonding and coating). Surface pretreatment should be done well before use based on specific needs.