ASTM D823 Standard Practices for Producing Films of Uniform Thickness of Paint, Coatings, and Related Products on Test Panels

Get Certified ASTM D823 Testing for Reliable Coating Film Evaluation 

ASTM D823 is used to prepare coating films with controlled and consistent thickness prior to performance evaluation. Skilled technicians select appropriate application practices according to the coating and intended application process. Application parameters are monitored, and film thickness is checked as required in appropriate ASTM procedures. Smooth test panels make subsequent coating evaluations more reliable and comparable.

The scope of ASTM D823 includes:

• Material: Paints, coatings and related liquid coating products applied to appropriate test panels. 
• Objective: Produce coating films with uniform and reproducible thickness for subsequent laboratory evaluation. 
• Property measurement: Film thickness and the consistency of the applied coating film; subsequent coating properties may depend on the prepared film. 
• Method: Automated spray, motor-driven dip coating, motor-driven blade application, hand-held spray gun application, or hand-held blade application. 
• Result: A test panel with a controlled-thickness coating film for coating performance testing.
• Test limitations: This practice does not specify a universal film thickness for all coatings. Application behavior depends on the coating, equipment, application conditions, and the practice selected. 
• Environmental conditions: Laboratories should control relevant application and conditioning conditions and establish appropriate safety, health, and environmental practices. 
• Applications: Coating development, quality control, appearance evaluation, comparative testing, and lab simulation of factory/field coating application.

What are the uses of ASTM D823 practices? 

ASTM D823 helps laboratories prepare consistent coating films before they perform other coating evaluations. This standard is especially helpful when the film thickness or application method may affect the test result. This standard-

• Helps technicians prepare uniform coating films on test panels. 
• Supports evaluation of coatings designed for spray application. 
• Provides several application techniques for different laboratory requirements. 
• Supports evaluation of metallic coatings for appearance properties such as gloss and color. 
• Helps laboratories produce comparable panels for coating-performance studies. 
• Allows suitable wire-wound drawdown-bar application through ASTM D4147 where appropriate.

Which Materials Can Be Tested Under ASTM D823? 

ASTM D823 applies to paints, coatings, and related coating materials that laboratories can apply to suitable test panels. The method of application will vary depending on the coating properties and the application process. Technicians can apply the coating using spray, dip or blade depending on the need for the evaluation of the coating.

Why is ASTM D823 Important?

A uniform film preparation provides a controlled starting point for coating evaluation. Differences in coating thickness or application technique can influence appearance and other measured coating properties, so laboratories need a repeatable application process before comparing materials.

ASTM D823 Testing Process and Data Collection 

During ASTM D823 film preparation, technicians document the coating identification, test-panel information, selected application practice, application equipment, and relevant application conditions. Analysts verify the resulting film thickness with an appropriate measurement procedure and retain the information needed to reproduce or compare the coating application. For spray application, personnel should also control compressed-air quality when compressed air atomizes the coating.

Common Challenges and Troubleshooting 

ASTM D823 film uniformity can vary when technicians do not control application speed, coating viscosity, fluid delivery, spray-gun tip size, nonvolatile content, blade movement, or panel preparation. A slight orange-peel or spray wave may also be visible on spray-applied coatings. Technicians must choose the proper application practice, keep equipment clean, create panels consistently, control application conditions as they relate to the material, and check wet or dry film thickness using the proper ASTM measurement technique.

Common Challenges and Troubleshooting 

ASTM D823 film uniformity can vary when technicians do not control application speed, coating viscosity, fluid delivery, spray-gun tip size, nonvolatile content, blade movement, or panel preparation. A slight orange-peel or spray wave may also be visible on spray-applied coatings. Technicians must choose the proper application practice, keep equipment clean, create panels consistently, control application conditions as they relate to the material, and check wet or dry film thickness using the proper ASTM measurement technique.

• Laboratories report the measured coating-film thickness using the applicable units and thickness-measurement method, such as an appropriate wet- or dry-film thickness procedure. 
• Technicians record the primary film-preparation result together with the coating identification, test-panel information, and selected ASTM D823 application practice. 
• Analysts document the application configuration, specimen or panel identification, equipment, relevant application conditions, and any visible observations such as uneven coverage, orange-peel, or spray-wave characteristics. 
• Engineers and analysts compare the prepared film thickness and coating observations with the requirements of the applicable coating specification or subsequent ASTM test method.

Link  to ASTM D823