ASTM D7868-21 PDF

Overview

ASTM D7868-21, titled Standard Practice for Determining the Dry Fall (Fog) Properties of Protective Coatings, is an international standard developed by ASTM. This standard provides a qualitative procedure to evaluate the dry fall properties of protective coatings, primarily focusing on the potential for overspray particles to dry before settling on neighboring surfaces. It is particularly relevant in minimizing property damage and managing insurance claims resulting from coating overspray, especially for environments where vehicles and other sensitive surfaces are present.

Dry fall coatings are designed so that airborne overspray particles desiccate and transform into a dust or powder before landing, allowing easy removal without causing damage. ASTM D7868-21 presents a reliable method for assessing these properties under realistic conditions prior to large-scale coating applications.

Key Topics

• Purpose: Evaluates the ability of protective coatings to form a non-adherent, removable layer of overspray dust, thereby mitigating accidental damage to unintended surfaces.
• Test Environment: Describes the use of enclosed test chambers and collection surfaces to simulate real-world overspray scenarios.
• Test Surfaces: Commonly utilizes automotive-finish panels; other substrates may be used to more accurately reflect specific project conditions.
• Removal Methods: Assesses removal using techniques such as dry brushing, washing with car wash concentrate, or using mineral spirits, based on the degree of attachment.
• Variable Conditions: Includes evaluation on both ambient and elevated surface temperature collection panels to reflect common field situations.
• Documentation: Specifies systematic reporting requirements, including environmental conditions, application method, and the effectiveness of overspray removal techniques.

Applications

ASTM D7868-21 finds wide practical use in industrial and commercial paint applications. Its main applications include:

• Evaluation Before Large-Scale Projects: Provides a structured approach to verifying that a coating product’s dry fall characteristics meet project requirements, reducing risks of overspray damage to vehicles, equipment, and nearby property.
• Specification for Industrial Coatings: Used by facilities managers, coatings manufacturers, and painting contractors to qualify products for use in factories, warehouses, parking garages, and similar environments.
• Quality Control and Product Development: Aids coatings formulators in developing and refining products specifically engineered to prevent costly overspray adhesion.
• Insurance and Risk Management: Supports evidence-based decisions in risk assessment and in responding to insurance claims related to paint overspray incidents.
• Evaluation on Heated Surfaces: Ensures coatings perform as required even when overspray settles on surfaces exposed to elevated temperatures, such as rooftops or sunlit vehicles.

Related Standards

Several related ASTM standards help ensure complete quality assessments and performance evaluations for coatings and surface preparation:

• ASTM D610: Practice for Evaluating Degree of Rusting on Painted Steel Surfaces – an essential standard for assessing corrosion resistance.
• ASTM D5402: Practice for Assessing the Solvent Resistance of Organic Coatings Using Solvent Rubs – useful for determining coating durability.
• Other dry fall, fog, and overspray-related standards may also apply depending on specific project needs.

Summary

ASTM D7868-21 sets out consistent methods for determining the dry fall properties of protective coatings, improving confidence in product selection, damage prevention, and overall coatings performance in settings where overspray is a concern. By following this standard practice, stakeholders can ensure both regulatory compliance and higher satisfaction in coating applications where clean, damage-free surroundings are critical.

Keywords: ASTM D7868-21, dry fall coatings, fog properties, protective coatings, overspray, industrial painting, coating evaluation, paint overspray removal.