1、Designation: D 6206 09Standard Practice forSampling of Coating Films1This standard is issued under the fixed designation D 6206; 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 ind
2、icates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers methods to remove samples ofcoating films for subsequent analysis related to identification ofgeneric coating type and failure analysis or
3、other reasons.These techniques can be used in the field, the fabricating shop,or laboratory.1.2 The method for obtaining coating samples for heavymetal analysis is presented in Practice D 5702.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are fo
4、r informationonly.1.4 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 u
5、se.2. Referenced Documents2.1 ASTM Standards:2D 4840 Guide for Sample Chain-of-Custody ProceduresD 5702 Practice for Field Sampling of Coating Films forAnalysis for Heavy Metals3. Significance and Use3.1 Specimens for analysis must be adequately sampled,packaged, and documented to obtain meaningful
6、informationfrom the laboratory. The sampling procedure and packagingwill be dependent upon the reason for taking the sample.4. Procedure4.1 General:4.1.1 Contaminating samples must be avoided. Hands mustbe kept clean by washing or wearing protective covers such aslatex gloves. Contact the laboratory
7、 that will perform theanalysis to determine if any other precautions are needed.Clean blades or knife between each sample with a rag soakedin solvent, or change blades between each sample.4.1.2 The number and location of samples will vary depend-ing upon the reason for sampling. Document the samplin
8、glocation prior to obtaining the sample. Measure and record dryfilm thicknesses. If delamination is present, measure and recorddry film thickness of the coating remaining in the delaminatedarea as well as the intact area. Record the type of delamination,that is, adhesive or cohesive, and the color o
9、f the coatinglayer(s) where the delamination occurred. Document any othervisual defects such as alligatoring, mudcracking, checking,blistering, non-uniform appearance, or chalking.4.1.3 Obtain any history of the coating system available.This should include when the coating was applied, the type ofco
10、ating, and intended dry film thicknesses. Obtain a copy of thepainting specification, if possible, to verify the information.4.1.4 Photograph the sample area before and after obtainingthe sample.4.1.5 Samples should be sent to the laboratory with achain-of-custody form, especially if there are exist
11、ing orpotential legal ramifications to the results of the laboratoryanalysis. Guide D 4840 presents the minimum requirements forsample chain-of-custody procedures.4.2 Peeling Paint or Paint with Poor Adhesion:4.2.1 Samples should be taken that have not had both sidesexposed to the elements. Make an
12、incision approximately 5 cm(2-in.) long in the coating using a sharp knife blade (such as autility knife). Hold the blade at a low angle to the surface andprobe the incision by pushing forward on the knife. Alterna-tively, it may be possible to remove the sample by cutting a 5cm (2-in.) square in th
13、e coating and peeling a sample byinserting the knife blade held at a low angle to the surface atone of the edges of the incision. For brittle coatings, maskingtape may be used to hold the film together during removal.4.2.2 Obtain at least three samples, each sample being atleast 5 cm (2-in.) square.
14、 Smaller samples are allowed ifa5cm(2-in.) square piece cannot be removed. Ensure that the threesamples represent the same system. Place the samples in aplastic bag, aluminum foil, or envelope. Mark the outside of1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coat
15、ings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved Feb. 1, 2009. Published February 2009. Originallyapproved in 1997. Last previous edition approved in 2003 as D 6206 - 03.2For referenced ASTM standards,
16、 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 194
17、28-2959, United States.the bag or envelope with the identity of the sample, includingdate, name of person taking the sample, project location, arealocation, and type of sample. Use a different container for eacharea sampled.4.2.3 Place a mark on the outer surface of the coating chipusing a felttippe
18、d pen or other available marker. If analysis ofthe topcoat is desired, identify the topcoat and disbondmentsurfaces in the documentation using attributes such as color,gloss, or obvious presence of a foreign substance. Record thelocation where the sample was obtained, whether the failureplane was be
19、tween coats or within a coat, and the identificationof the top coat and disbondment surfaces. Request the labora-tory to identify cause of disbondment.4.3 Paint with Solvent Odor or Suspected Volatile Material:4.3.1 The important step in obtaining samples of paint filmsfor identification of retained
20、 solvents is to deposit the sample ina tightly closed container as quickly as possible. A septum-topvial is the preferred container. A screw-top vial or jar isacceptable. The vial or jar should have the top removed priorto obtaining the sample.4.3.2 For samples of peeling paint, select an area of po
21、oradhesion where the paint is not visually disbonded. Remove asample as described in 4.2.1. Place it immediately in thecontainer and screw the top tightly onto the vial or jar. Do notreopen the jar. Other samples are to be placed in differentcontainers. Take a minimum of three samples.4.3.3 Record t
22、he location where the sample was obtained.Request the laboratory to identify the solvent odor.4.4 Sampling of Top Coat:4.4.1 It may be necessary to identify the generic coatingtype of a top coat in order to determine its compatibility withovercoating materials. There are the following three possible
23、sampling methods: paint chip, paint sanding, and paint scrap-ings.4.4.1.1 Paint Chip Method: If it is possible to obtain a paintchip, even if it contains multiple layers, the best method is tolet the laboratory obtain a sample of the top coat. A sample atleast 10 cm (5-in.) square should be obtained
24、. Identify the colorof the top coat if there is more than one layer in the paint chip.4.4.1.2 Paint Sanding Method: Sanding is used to obtainsamples of top coat of tightly adherent coatings (or samples ofexposed coating) from a delaminated area. Clean the surface ofdust, dirt, and debris by washing
25、with clean water and a rag.Fold a piece of paper lengthwise to make a trough, and tape itimmediately below the sampling location. Using a fine-gradesandpaper or emery cloth, rub the surface in a circular patternuntil enough coating to cover a fingernail has been removedfrom the surface. Examine the
26、sampling location to determineif the top coat had been penetrated and the next coat is visible.(Discard the sample if the next coat is visible at the samplinglocation.) Place the sample in a small vial. If no vial isavailable, take the paper and place the sample in the middle ofthe trough by lifting
27、 the ends of the trough. Fold the paper inthirds lengthwise, and then in half in the opposite direction.Place the paper in a plastic bag or envelope, and seal. Mark theoutside of the bag or envelope with the identity of the sample,including date, name of person taking the sample, projectlocation, ar
28、ea location, and type of sample.4.4.1.3 Paint Scrapings Method: Scraping with a sharpblade is used to obtain samples of the top coat of tightlyadherent coatings (or samples of exposed coating) fromdelaminated areas. The procedure is the same as sanding excepta sharp blade such as a single-edge razor
29、 blade or utility knifeblade is used. The blade edge is held perpendicular to thesurface. The long edge of the blade is pressed with sufficientpressure over the surface so that tiny pieces of the coating areremoved. However, greater care is needed when using a bladeas it is easier to cut into the co
30、ating and obtain small specimensof lower coating layers. The surface must be examined morecarefully after taking the sample to determine that the samplehas not been contaminated.4.4.2 Document the sample location and method used toobtain the sample. Request the laboratory to identify thegeneric type
31、 of coating.5. Report5.1 Maintain field notes that include the following informa-tion: structure sampled, date, name of sampler, unique identi-fication number for each sample, location on the structure ofeach sample, location in coating film of failure (if applicable),dry film thickness measurements
32、, film condition, and any otherobservations.5.2 When using a chain-of-custody form, include uniqueidentification number, type of sample, number of samples, andtype of container for each sample. Sign and date the chain-of-custody form just prior to sealing the package, or whenhanding the package to t
33、he next person who takes custody.5.3 Provide information to the laboratory on tests to performor information desired using an analysis request form,chainofcustody form, or letter.6. Keywords6.1 coating films; paint and coating; sampling methodsD6206092ASTM International takes no position respecting
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