Wall Putty Powder Formula

Wall putty powder is a powder material used before painting to pre-treat and level building surfaces. Its main function is to fill pores in the substrate and correct unevenness deviations, laying the foundation for a uniform and smooth paint finish. The following will introduce reference formulas and key components of several common putty powders.

I. Interior Wall Putty

**Interior Wall Polishing Waterproof Putty**

This formula emphasizes surface smoothness and water resistance, suitable for interior wall substrate treatment with high requirements. The main components are heavy calcium carbonate and lime, with a suitable amount of hydroxypropyl methylcellulose (HPMC, viscosity approximately 100,000 mPa·s) as a water-retaining and binding component, providing good workability and sanding properties, and exhibiting certain water resistance after film formation.

**Interior Wall Primer Waterproof Putty**

This formula focuses on substrate leveling and improved adhesion. Using a high proportion of heavy calcium carbonate, combined with appropriate amounts of lime and hydroxypropyl methylcellulose (HPMC, viscosity approximately 100,000 mPa·s), this product ensures basic water resistance while offering good application performance and cost advantages. It is typically used as a priming agent before applying the topcoat putty.

II. Exterior Wall Putty

Exterior Sandy Putty: This system emphasizes crack resistance and mechanical strength. It uses cement as the main binder, composite quartz sand as aggregate, and adds redispersible latex powder and hydroxypropyl methylcellulose. Its formula effectively resists changes in substrate stress, providing excellent impact resistance and weather resistance, suitable for crack-resistant leveling of exterior walls.

Ordinary/Flexible Waterproof Exterior Wall Putty: A general-purpose exterior wall leveling material. Based on a mixture of white cement and heavy calcium carbonate, hydroxypropyl methylcellulose (HPMC, viscosity approximately 100,000 mPa·s) is used to adjust workability and water retention. The formula is simple and meets the general waterproofing and strength requirements of exterior walls.

Flexible Waterproof Crack-Resistant Exterior Wall Putty

This product further enhances the toughness and crack resistance of ordinary exterior wall putty. Redispersible latex powder is added to improve flexibility, while wood fibers and short polypropylene fibers are introduced to form a three-dimensional crack-resistant network. This system effectively adapts to matrix deformation and resists the generation and development of micro-cracks.

III. 821 Putty

This is a common economical interior wall putty system, typically free of cement and lime. It mainly relies on organic cementitious materials to provide adhesion, such as the combined use of pregelatinized starch and sodium carboxymethyl cellulose (CMC), or the direct use of dedicated 821 adhesive powder. Its characteristics include low cost, easy application, and high whiteness, but its water resistance is generally average. It is suitable for leveling interior walls in ordinary dry environments.

Precautions

The above formulas are for reference only. In actual production, adjustments and optimizations are needed based on the performance of raw materials, the construction environment, and specific product standards. Key additives such as the viscosity and purity of hydroxypropyl methylcellulose and the film-forming temperature of latex powder significantly affect the final product performance. It is recommended to determine the optimal ratio through systematic testing.