In applications such as electronic protection, insulating sealing, and surface coating, the application quality of silicone coatings directly affects the protective performance and service life of the final product. However, in actual production, many users encounter issues such as bubbles, crawling, pinholes after coating, or poor adhesion between the coating and substrate leading to easy detachment—not only affecting product appearance but potentially causing protection failure.

The root causes of such problems can generally be attributed to four aspects. First, poor substrate surface condition: if the substrate surface has oil contamination, dust, mold release agent residue, or an oxide layer, it will directly compromise the interfacial bonding force between the silicone and substrate, leading to crawling and reduced adhesion. Second, improper silicone viscosity selection: when viscosity is too high, leveling performance is poor, and bubbles within the coating cannot escape in time; when viscosity is too low, sagging or insufficient coating thickness may occur. Third, unreasonable curing process: when curing speed is too fast, the surface layer cures first to form a "skin," trapping internal bubbles that cannot escape. Fourth, polarity mismatch between substrate and silicone: particularly for non-polar materials such as PP and PE, silicone struggles to wet and spread.

To address these issues, it is recommended to troubleshoot and optimize through the following four steps. First, substrate pretreatment: wipe with alcohol or use plasma cleaning to remove surface contaminants before coating; for metal substrates, sandblasting or anodizing can be performed to increase surface roughness. Second, viscosity selection: for thin-layer coating (0.1–0.5 mm), select low-viscosity products (500–3,000 mPa·s); for thick-layer coating (0.5–2 mm), select medium-viscosity products, with dedicated thinners added when necessary to adjust flowability. Third, curing process optimization: adopt a staged curing strategy—first pre-cure at 60–80°C for 1–2 hours to allow bubbles to fully escape, then raise to 120–150°C for complete curing. Fourth, adhesion improvement: use dedicated primers for difficult-to-bond substrates, which can significantly enhance coating bonding strength.

It should be noted that coating thickness is recommended to be controlled between 0.1 and 2 mm. Coatings that are too thick easily generate internal stress leading to cracking, while those that are too thin provide insufficient protection. The application environment should also be kept clean and dry, with relative humidity controlled below 60% to avoid moisture interference with the curing reaction.

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