Abstract <p>This article discusses ways to improvements in the performance characteristics of two-pot heat-resistant electrical insulating paints and varnishes based on polymethylphenylsiloxane resin and various alkoxysilanes. Optimum ratios of mixture components are established, ensuring the achievement of the most effective results. It is established that the introduction of alkoxysilanes as hardeners for polymethylphenylsiloxane resin leads to a significant improvement in the dielectric and performance characteristics of the resulting varnish coatings, which indicates a significant potential of this approach for optimizing process parameters and improving the performance properties of paint coatings. The research results confirm the perspectiveness of use of alkoxysilanes to improve the physical and mechanical characteristics of two-pot heat-resistant electrical-insulating varnish coatings. A significant increase in thermal stability and mechanical strength is noted, which makes paint and varnish coatings based on them competitive in the market of materials for processing and anticorrosion protection of metal structures exposed to physical, mechanical, and high temperature loads.</p>