ASTM_C_724_-_91_2015.pdf

Designation:C72491(Reapproved 2015)Standard Test Method forAcid Resistance of Ceramic Decorations on Architectural-Type Glass1This standard is issued under the fixed designation C724;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers qualitative determination of theacid resistance of the ceramic decoration on architectural glass.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Terminology2.1 Definitions:2.1.1 architectural glassglass used in the building indus-try.3.Summary of Test Method3.1 This test method qualitatively determines,by visualinspection,the degree of attack upon a ceramic decoration bya 10%citric acid solution and a nominal 3.7%hydrochloricacid solution.4.Significance and Use4.1 This test method evaluates the quality and serviceabilityof a ceramic decoration on architectural type glass.The degreeof attack is determined using an acidic solution both quantita-tively and qualitatively.4.2 This test method provides a convenient control testduring the manufacture of the ware.4.3 This test method is suitable for specification acceptance.5.Reagent5.1Purity of Reagents Reagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.2Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 Citric Acid Solution(1+9)Add 10 parts by mass ofreagent grade citric acid to 90 parts by mass of distilled water.Prepare fresh for each determination.5.3Hydrochloric Acid Solution(1+9)Add 10 parts bymass of reagent grade concentrated hydrochloric acid(HCl)(36 to 38%)to 90 parts by mass of distilled water.6.Procedure6.1 Place four drops of each acid solution on a separatelocation on the surface of the ceramic decoration of thearchitectural glass to be tested.Cover each spot with awatchglass to retard evaporation and prevent contamination.Acid should remain on the surface of the test specimen for 15min at 20 62C.6.2 After 15 min of exposure,wash the acid solutions(1+9)from the test specimen with tap water and allow it to airdry.7.Report7.1 Report the following information:7.1.1 The degree of attack by visual observation by gradingas follows:Grade 1No attack apparentGrade 2Appearance of iridescence or visible stain on theexposed surface when viewed at a 45 angle but not apparentat angles less than 30Grade 3A definite stain which does not blur reflectedimages and is visible at angles less than 301This test method is under the jurisdiction of ASTM Committee C14 on Glassand Glass Products and is the direct responsibility of Subcommittee C14.10 onGlass Decoration.Current edition approved May 1,2015.Published May 2015.Originallyapproved in 1974.Last previous edition approved in 2010 as C724 91(2010).DOI:10.1520/C0724-91R15.2Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Grade 4Definite stain with a gross color change orstrongly iridescent surface visible at angles less than 30 andwhich may blur reflected imagesGrade 5Surface dull or matte with chalking possibleGrade 6Significant removal of enamel with pinholingevidentGrade 7Complete removal of enamel in exposed area8.Precision and Bias8.1PrecisionIn round-robin testing and evaluation,thebetween-laboratory precision for citric-acid resistance determi-nation was found to be 61 grade(95%students t).Thewithin-laboratory precision for citric-acid resistance determi-nation is estimated at no greater than 61 grade.8.2BiasNo justifiable statement can be made about thebias of this test method,because the subjective nature ofgrading may vary considerably among operators.9.Keywords9.1 acid resistance;architectural decorations;ceramicenamels;chemical durabilityASTM International takes no position respecting the validity of any paten