ASTM_D_7072_-_04_2013.pdf

Designation:D707204(Reapproved 2013)Standard Practice forEvaluating Accelerated Efflorescence of Latex Coatings1This standard is issued under the fixed designation D7072;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 practice covers the evaluation of the degree towhich a latex paint resists the formation of efflorescence andalkali burnout on the exposed paint surface.1.2 This practice is designed primarily to relate efflores-cence originating in the substrate to the deposit appearing onthe surface of latex paints.This practice relates chiefly to thepainting of masonry-type substrates such as concrete block,brick,mortar,stucco,poured concrete and similar materials.1.3 The values in SI units are to be regarded as the standard.The values in parenthesis are for information only.1.4 This method does not purport to address all of the safetyconcerns,if any,associated with its use.It is the responsibilityof whoever uses this standard to consult and establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1475 Test Method For Density of Liquid Coatings,Inks,and Related ProductsD1734 Practice for Making Cementitious Panels for TestingCoatingsD4585 Practice for Testing Water Resistance of CoatingsUsing Controlled CondensationD5068 Practice for Preparation of Paint Brushes for Evalu-ation3.Terminology(Specific to this Practice)3.1 Definitions of Terms Specific to This Standard:3.1.1 efflorescence,nthe deposition of soluble salts on theexposed paint surface.Efflorescence is characterized by a lightcolored,nonuniform,powdery incrustation which detractsfrom the paint film appearance.The discoloration occurs whensoluble salts in the substrate or paint migrate to the surface bythe leaching and evaporating action of the water carrier.Theefflorescence originating within the substrate is that with whichthis method is concerned.3.1.2 alkali burnout,nthe premature fading or decompo-sition of paints that are sensitive to the high pH of the substrate.The high alkaline content of the substrate can alter the color.4.Summary of Practice4.1 Panels known to have a level of salts capable of beingeasily and quickly transported to the paint surface are used.Since tinted paints show the efflorescence most clearly,allwhite paints should be tinted before application.The panel isplaced face down over the surface of the test chamber whichcontains heated water,so that moisture condenses and remainson the painted surface of the panel for a period of 48 h.Afterdrying at ambient conditions,the panels are rated for thedegree of efflorescence which has formed.5.Significance and Use5.1 Latex paints are sometimes applied over substrates thatcontain a high level of water soluble salts that result inefflorescence.This practice evaluates a coatings vulnerabilityto efflorescence.6.Apparatus6.1 Condensation Test ChamberAs described in PracticeD4585.6.2 Test SubstrateFiber-cement siding3or a substrateagreed upon by the purchaser and seller.The substrate sizewould depend on the number of test paints.6.3 White Portland Cement and Graded Standard Sand(asdescribed in Practice D1734).6.4 Trowel(as described in Practice D1734).6.5 Paint BrushNylon/polyester brush of good quality.6.6 Electronic Scale capable of 0.1 g.1This practice is under the jurisdiction of Committee D01 on Paint and RelatedCoatings,Materials,and Applications and is the direct responsibility of Subcom-mittee D01.42 on Architectural Coatings.Current edition approved on July 1,2013.Published July 2013.Originallyapproved in 2004.Last previous edition approved in 2009 as D7072 04(2009).DOI:10.1520/D7072-04R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Hardieplank,a registered trademark of James Hardie,was found to beacceptable but others may be used.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.Reagents and Materials7.1 Control Paint(s)(preferably tinted)The use of twocontrols(a pass and fail)may help gage the performance of thetest paints.7.2 Test Paints(preferably tinted)Since there are nostandard panels,photographs,or paints for this test method,anagreed-upon control paint should be included as one of the testpaints.7.3 Using identical or similar tints for control(s)and testpaints may aid in relative evaluation of different formulations.7.4 If the goal is to evaluate alkali burnout,usually brightorganic colors will be more susceptible.8.Procedure8.1 Mix the cement:sand:water in