ASTM C724-91(2020)

Standard Test Method for Acid Resistance of Ceramic Decorations on Architectural-Type Glass

SIGNIFICANCE AND USE
4.1 This test method evaluates the quality and serviceability of a ceramic decoration on architectural type glass. The degree of attack is determined using an acidic solution both quantitatively and qualitatively.  
4.2 This test method provides a convenient control test during the manufacture of the ware.  
4.3 This test method is suitable for specification acceptance.
SCOPE
1.1 This test method covers qualitative determination of the acid resistance of the ceramic decoration on architectural glass.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jul-2020
• ICS: 81.040.20 - Glass in building
• Technical Committee: C14 - Glass and Glass Products
• Drafting Committee: C14.10 - Glass Decoration

Relations

• Replaces: ASTM C724-91(2015) - Standard Test Method for Acid Resistance of Ceramic Decorations on Architectural-Type Glass
• Effective Date: 01-Aug-2020
• Referred By: ASTM C1048-18 - Standard Specification for Heat-Strengthened and Fully Tempered Flat Glass
• Effective Date: 01-Aug-2020
• Referred By: ASTM E3223/E3223M-20 - Standard Guide for Specifying and Testing Field-Constructed Exterior Building Wall System Mockups in New Construction
• Effective Date: 01-Aug-2020
• Referred By: ASTM E2813-18 - Standard Practice for Building Enclosure Commissioning
• Effective Date: 01-Aug-2020

Overview

ASTM C724-91(2020): Standard Test Method for Acid Resistance of Ceramic Decorations on Architectural-Type Glass establishes a qualitative procedure to determine how well ceramic decorations, such as enamels and decorative coatings, withstand acid attack when applied to architectural glass. This standard is maintained by ASTM International and is widely recognized as an essential quality control and specification acceptance tool in the building and glass manufacturing sectors.

The test utilizes specified acid solutions to simulate aggressive environments that architectural glass may encounter. Results are visually graded, offering a practical method for evaluating the durability and serviceability of decorative finishes in real-world applications.

Key Topics

• Acid Resistance Assessment: Focuses on the qualitative evaluation of the chemical durability of ceramic decorations when exposed to acidic environments.
• Test Solutions: Uses citric acid and hydrochloric acid in controlled concentrations to assess the level of attack on decorated glass surfaces.
• Visual Grading: The degree of damage is determined via inspection, using a defined grading scale ranging from no apparent attack to complete removal of enamel.
• Manufacturing Control: Provides a standardized test to monitor quality during production, ensuring consistent performance of ceramic decorations.
• Specification Acceptance: Suitable as a benchmark test for compliance with contract or regulatory requirements in the architectural glass industry.
• SI Units: All measurements and values are stated in International System (SI) units, promoting international consistency.
• User Responsibility: Emphasizes that users must implement appropriate safety, health, and environmental practices and comply with all applicable regulations.

Applications

ASTM C724-91(2020) is widely applied in the following areas:

• Architectural Glass Manufacturing: Ensures quality and durability of decorative finishes on glass panels used in buildings, facades, and interior partitions.
• Quality Control Laboratories: Provides a repeatable method for routine in-process and final product testing.
• Product Development: Assists manufacturers in formulating ceramic enamels and decorations with proven acid resistance to enhance product performance.
• Specification and Procurement: Used by architects, builders, and specifiers as a criterion for selecting glass products with durable decoration.
• Regulatory and Contract Compliance: Serves as a reference test method in bidding documents, standards compliance, and product certification.

By following this standard, stakeholders help ensure that decorated architectural glass products can withstand urban, industrial, and environmental exposures that involve acidic substances, maintaining both aesthetic and structural integrity.

Related Standards

For comprehensive quality assurance in architectural glass and ceramics, consider these related ASTM standards:

• ASTM C1048 – Standard Specification for Heat-Treated Flat Glass-Kind HS, Kind FT Coated and Uncoated Glass
• ASTM C1503 – Standard Specification for Silvered Flat Glass Mirror
• ASTM C205 – Standard Test Methods for Chemical Durability of Vitreous China, Fireclay, and Porcelain Enamels
• ASTM C1376 – Standard Specification for Pyrolytic and Vacuum Deposition Coatings on Flat Glass

These standards, when used in conjunction with ASTM C724-91(2020), provide a robust framework for ensuring the durability, safety, and visual quality of architectural glass products.

Keywords: ASTM C724-91, acid resistance, ceramic decorations, architectural glass, enamel durability, glass quality control, acid test method, specification acceptance

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C724 − 91 (Reapproved 2020)
Standard Test Method for
Acid Resistance of Ceramic Decorations on Architectural-
Type Glass
This standard is issued under the fixed designation C724; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4.2 This test method provides a convenient control test
during the manufacture of the ware.
1.1 This test method covers qualitative determination of the
acid resistance of the ceramic decoration on architectural glass. 4.3 This test method is suitable for specification acceptance.
1.2 The values stated in SI units are to be regarded as
5. Reagent
standard. No other units of measurement are included in this
5.1 Purity of Reagents—Reagent grade chemicals shall be
standard.
used in all tests. Unless otherwise indicated, it is intended that
1.3 This standard does not purport to address all of the
all reagents shall conform to the specifications of the Commit-
safety concerns, if any, associated with its use. It is the
tee onAnalytical Reagents of theAmerican Chemical Society,
responsibility of the user of this standard to establish appro-
where such specifications are available. Other grades may be
priate safety, health, and environmental practices and deter-
used, provided it is first ascertained that the reagent is of
mine the applicability of regulatory limitations prior to use.
sufficiently high purity to permit its use without lessening the
1.4 This international standard was developed in accor-
accuracy of the determination.
dance with internationally recognized principles on standard-
5.2 Citric Acid Solution(1+9)—Add ten parts by mass of
ization established in the Decision on Principles for the
reagent grade citric acid to 90 parts by mass of distilled water.
Development of International Standards, Guides and Recom-
Prepare fresh for each determination.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
5.3 Hydrochloric Acid Solution (1 + 9)—Add ten parts by
mass of reagent grade concentrated hydrochloric acid (HCl)
2. Terminology
(36 to 38 %) to 90 parts by mass of distilled water.
2.1 Definitions:
6. Procedure
2.1.1 architectural glass, n—glass used in the building
6.1 Place four drops of each acid solution on a separate
industry.
location on the surface of the ceramic decoration of the
architectural glass to be tested. Cover each spot with a
3. Summary of Test Method
watchglass to retard evaporation and prevent contamination.
3.1 This test method qualitatively determines, by visual
Acid should remain on the surface of the test specimen for
inspection, the degree of attack upon a ceramic decoration by
15 min at 20 62 °C.
a 10 % citric acid solution and a nominal 3.7 % hydrochloric
6.2 After 15 min of exposure, wash the acid solutions
acid solution.
(1 + 9) from the test specimen with tap water and allow it to air
4. Significance and Use dry.
4.1 This test method evaluates the quality and serviceability
7. Report
of a ceramic decoration on architectural type glass. The degree
7.1 Report the following information:
of attack is determined using an acidic solution both quantita-
7.1.1 The degree of att
...