ASTM D1748-02(2008)
(Test Method)Standard Test Method for Rust Protection by Metal Preservatives in the Humidity Cabinet
Standard Test Method for Rust Protection by Metal Preservatives in the Humidity Cabinet
SIGNIFICANCE AND USE
This test method is used for measuring the relative abilities of metal preservatives to prevent the rusting of steel panels under conditions of high humidity. It should not be relied upon to predict the effectiveness of a metal preservative in which high humidity is not the principal factor in the rusting.
Comparisons made by this test method should normally be limited to similar metal preservative combinations designed for similar applications. The test life required for each type of metal preservative and for each intended application should be based on actual experience with that type of preservative in the intended service.
Since the precision of the test method appears to be less than desired, a number of repeat tests may be necessary to establish the test life of a given metal preservative, and repeat tests by this test method in more than one cabinet are sometimes desirable.
The data obtained from this accelerated test is of interest only in eliminating the most unsuitable materials or for indicating a probable relative order of protection against rust under conditions of high humidity. This test method does not prescribe the exposure periods to be used for a specific product, nor the interpretation to be given to the results.
SCOPE
1.1 This test method covers the evaluation of the rust-preventive properties of metal preservatives under conditions of high humidity.
1.2 The values stated in SI units are to be regarded as the standard except where the test apparatus or consumable parts are only available in other units. In such cases these will be regarded as standard. The values given in parentheses are for information only.
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 consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D1748 – 02 (Reapproved 2008)
Designation: 366/84
Standard Test Method for
Rust Protection by Metal Preservatives in the Humidity
Cabinet
This standard is issued under the fixed designation D1748; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope QQ-S-698 Steel Sheet and Strip, Low Carbon
2.3 Military Standards:
1.1 This test method covers the evaluation of the rust-
MIL-C-5646F Cloth, Airplane
preventive properties of metal preservatives under conditions
MIL-C-15074E Corrosive Preventive Compound Finger
of high humidity.
Print Remover
1.2 The values stated in SI units are to be regarded as the
2.4 Society of Automotive Engineers:
standard except where the test apparatus or consumable parts
SAE 1009C Tee Reducer, Bulkhead on Side, Flareless Tube
are only available in other units. In such cases these will be
regarded as standard. The values given in parentheses are for
3. Summary of Test Method
information only.
3.1 Steel panels are prepared to a prescribed surface finish,
1.3 This standard does not purport to address all of the
dipped in the test oil, allowed to drain, and then suspended in
safety concerns, if any, associated with its use. It is the
a humidity cabinet at 48.9°C (120°F) for a specified number of
responsibility of the user of this standard to consult and
hours. The oil fails or passes the test in accordance with the
establish appropriate safety and health practices and deter-
size and number of rust dots on the test surfaces of the panels.
mine the applicability of regulatory limitations prior to use.
4. Significance and Use
2. Referenced Documents
2 4.1 This test method is used for measuring the relative
2.1 ASTM Standards:
abilities of metal preservatives to prevent the rusting of steel
A109/A109M Specification for Steel, Strip, Carbon (0.25
panels under conditions of high humidity. It should not be
Maximum Percent), Cold-Rolled
relied upon to predict the effectiveness of a metal preservative
D512 Test Methods for Chloride Ion In Water
inwhichhighhumidityisnottheprincipalfactorintherusting.
D516 Test Method for Sulfate Ion in Water
4.2 Comparisons made by this test method should normally
E11 SpecificationforWovenWireTestSieveClothandTest
be limited to similar metal preservative combinations designed
Sieves
for similar applications. The test life required for each type of
E323 Specification for Perforated-Plate Sieves for Testing
metal preservative and for each intended application should be
Purposes
3 based on actual experience with that type of preservative in the
2.2 Federal Standards:
intended service.
4.3 Since the precision of the test method appears to be less
This test method is under the jurisdiction of ASTM Committee D02 on
than desired, a number of repeat tests may be necessary to
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
establish the test life of a given metal preservative, and repeat
D02.L0.03 on Corrosion Testing of Sheet Fluids Metal Processing Fluids.
tests by this test method in more than one cabinet are
CurrenteditionapprovedMay1,2008.PublishedJuly2008.Originallyapproved
in 1960. Last previous edition approved in 2002 as D1748–02. DOI: 10.1520/
sometimes desirable.
D1748-02R08.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from Standardization Documents Order Desk, Bldg. 4, Section D,
the ASTM website. 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
3 5
Available from Superintendent of Documents, U.S. Government Printing Available from Society of Automotive Engineers, 400 Commonwealth Dr.,
Office, Washington, DC 20402. Warrendale, PA 15096.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D1748 – 02 (2008)
4.4 Thedataobtainedfromthisacceleratedtestisofinterest
Cover opening to a height of 355 mm (14 in.) at
the front
only in eliminating the most unsuitable materials or for
indicating a probable relative order of protection against rust
A
under conditions of high humidity. This test method does not Boil the water sample with 10 mL of saturated bromine water before making
the test for sulfates.
prescribetheexposureperiodstobeusedforaspecificproduct,
7.2 Rate of air to the cabinet, air temperature, pH, and water
nor the interpretation to be given to the results.
level shall be checked and regulated if necessary twice each
day, at 7- to 8-h intervals. Remaining standard conditions shall
5. Apparatus
be closely checked once each week.The pH measurement may
5.1 The apparatus shall conform to the details shown in the
be made with wide-range indicator paper.
Annex A1.
NOTE 4—Values for pH outside the limits shown indicate contamina-
6. Panel Cleaning Materials tion that should be investigated and corrected. A persistent low pH along
with a positive sulfate test indicates that the air supply is contaminated
6.1 Aluminum Oxide Cloth, 240-grit.
with sulfur oxides. In this case, the water in the cabinet should be
replaced, and a suitable alkali scrubber system installed in the air train.
NOTE 1—Paper-backed abrasives, wet or dry, waterproof, or iron oxide
NOTE 5—Details of the cabinet operation described in 7.1 and 7.2 and
abrasives are prohibited.
the details of panel preparation described in Section 8, must be carefully
6.2 Silica Sand, white, dry, sharp, chloride free, or alumi-
carried out. Only by such standardization can results be obtained that are
num oxide, blasting grade. (The size shall be such that it meets
significant and comparable to those run at another time or in another
the following sieve requirements of Specifications E11 and
laboratory.
E323.
8. Panel Preparation
6.2.1 One hundred percent must pass through a No. 10
(2.00-mm) sieve. 8.1 Remove the protective packaging from all the panels to
6.2.2 Minimum of 90 % must pass through a No. 20 be used for a particular day and wash away the rust preventive
material in a beaker of solvent selected in 6.3 (swabbing is
(850-µm) sieve.
6.2.3 Maximum of 10 % permitted to pass through a No. 50 permissible using materials defined in 6.4). Carefully inspect
(300-µm) sieve. eachpanelanduseonlythosewhichcomplywithrequirements
6.3 Cleaners—Select a cleaning media and method, which given in A1.10. Identify each panel by an appropriate number
is safe, non-film forming and which does not in any way attack in the right-hand lower corner, outside of the significant area,
or etch the surface chemically. In addition, no Class 1 ozone or by attaching a small metal tag to the outside wire hook after
depletingsubstancesconformingtoSection602(a)oftheClean the panel is polished.
Air Act Amendments of 1990 (42USC7671a) as identified in 8.2 The following are pertinent to the polishing operations:
Section 326 of PL102-484 should be used. Use a procedure as 8.2.1 Do not allow the bare fingers to touch the panel.
outlined in Test Method F22 to judge the merit of the selected Tongs, metal hooks, or pieces of lint-free paper are suitable
cleaning technique. helpers for manipulating and holding the panel.
8.2.2 Always keep the panel on a clean, dry surface.
NOTE 2—Atypical solvent found acceptable for this purpose is hexane
8.3 Alternative Surface Finishes—Polishing:
or Stoddard solvent.
8.3.1 The amount of polishing of the panel by the operator
NOTE 3—The original precision was developed using a combination of
conducting the humidity cabinet test should only be that
petroleum naphtha and methanol.These are no longer used due to toxicity
issues.
required to give it a fresh, clean, and active surface. This
requires only a few minutes per panel. A fast-moving belt
6.4 Gauze, lint free cotton or gauze pads.
sandershouldnotbeusedsincetheheatoffrictionmaychange
the surface characteristics of the panel. Surface finish limits for
7. Humidity Cabinet Operating Conditions
the panel are not defined here. There should be no appreciable
7.1 During evaluation of a sample the cabinet shall be run
change of the finish from the 0.25 to 0.51 µm (10 to 20 µm)
continuously with the following standard conditions being
obtained by the original surface grinding A1.10.1.3.
maintained:
8.3.2 Divide the 240-grit aluminum oxide abrasive cloth
Air temperature:
into convenient size strips for the subsequent polishing opera-
Inside the cabinet 48.9 6 1.1°C (120 6 2.0°F)
Outside the cabinet 24.1 6 5.5°C (75.4 6 10.0°F)
tions. Observing the precautions given in 8.2 and 8.3, buff all
Rate of air to the cabinet (31.0 6 1ft /h) at 25.0°C and
four of the rounded edges with even strokes in the direction of
0.878 6 0.028 m /h 760 mm Hg
each edge. Ream out the two holes used for suspension and
Water in cabinet:
Level 203.0 6 6.4mm(8.0 6 ⁄4 in.)
wipe clean, using gauze wet with solvent selected in 6.3.
pH 5.5 to 7.5
8.3.3 While polishing, place the panel on a clean, dry
Oil content clear with no evidence of oil
surface with a suitable thickness of clean paper under it to help
Chlorides less than 20 ppm (Test Methods
D512)
prevent contamination. The panel may be held by hand, using
A
Sulfates and sulfites less than 20 ppm as sulfate (Test
paper between the fingers and the steel surface.Alternatively it
Method D516)
maybeheldinaspecialholdersuchasawoodenblock,having
Speed of rotating 0.33 6 0.03 rpm
about a 1.6-mm ( ⁄16-in.) depression slightly larger in area than
Cover close fitting
Cloth layers in cover shall not be torn, contaminated, the 51- by 102-mm (2- by 4-in.) dimension of the panel. The
nor contain droplets of water
abrasive cloth may be held in the palm of the hand with the
D1748 – 02 (2008)
fingers applying pressure to the panel. Alternatively, the 8.3.9 Spray the test surface, then the back of the panel, and
aluminum oxide cloth may be held on a block of size the test surface again.
convenient to the hand and convenient for polishing with 8.3.10 Rinse the panels in hot solvent selected in 6.3, and
smooth strokes without marking the ends of the panel. store in a desiccator until cool.
8.3.11 Use panels the same day as prepared.
8.3.4 Polish the unnumbered or leading surface of the panel
with careful even strokes, always parallel to the 102-mm 8.4 Alternative Surface Finishes—Sand or Aluminum Oxide
Blasting:
(4.0-in.) dimension. Use a polishing pressure of about 4.5 to
8.9 N (1.0 to 2.0 lb). Do not scratch the surface by using short 8.4.1 Blast the edges and lightly blast the backs of the
panels with the blasting material.
or curved strokes. Ensure that the panel is held firmly so that
only the abrasive cloth moves.After several polishing strokes, 8.4.2 Blast the unnumbered side, or test surface, of the
panels to a fresh, uniformly abraded surface. (Operation
inspect the abrasive cloth and when necessary make another
fold to expose a new and effective area. Continue to polish the 177.9–355.8 N of the blasting equipment at 40- to 80-lb
pressureandholdingtheworkpiece50.8to76.2mm(2to3in.)
leadingsurfaceuntilitcontainsacompletelyfreshsurface.The
finish should be within the range from 0.25 to 0.51 µm (9.8 to from the nozzle is recommended.)
20.0 µin.) (rms). Examine the entire surface, and if scratches or 8.4.3 Immediately after blasting, place the panels in a
beaker of nonreactive solvent or an ultrasonic cleaning bath
other imperfections are noted, continue polishing until cor-
rected. In the same manner polish the second side of the panel, containing nonreactive solvent.
8.4.4 Heat the solvent selected in 6.3 so that the solvent will
unless the test specification requires only one polished side per
panel. evaporate from the panels immediately upon withdrawal from
the solvent.
NOTE 6—It is advisable for each operator to finish several panels to
8.4.5 Remove remaining residue by holding the panels in a
determine exactly what technique is required to attain the correct surface
rack at 20° from the vertical and spraying downward with
finish using a profilometer or other surface roughness gage. After
solvent selected in 6.3.
techniques have been established, the use of visual comparison standards
is sufficient as a check on surface roughness. 8.4.6 Spray the test surface, then the back of the panel, and
the test surface again.
8.3.5 Remove the dust from the abrasive operation, using
8.4.7 Rinse the panels in hot solvent selected in 6.3, and
clean gauze wet with solvent selected in 6.3. Finally, wipe with
store in a desiccator until cool.
clean surgical gauze until there is no dark stain on a clean
8.4.8 Panels are to be used the same day as prepared.
section of the gauze. Remove any dust in the holes by use of a
pipe cleaner. (This may be followed by an ultrasonic cleaning
9. Procedure
bath procedure.) Submerge the panel completely in solvent
9.1 Bring the sample oil to a temperature of 23.3 6 0.5°C
selected in 6.3 at room temperature.
(74.0 6 1.0°F) and pour into a clean, dry 400-mL tall-form
glass beaker (for example, borosilicate glass) to a height of at
NOTE 7—The following should be carried out periodically as a check
on surface cleanliness: Place the cleaned panel directly under a buret on least 114 mm (about 375 mL). By use of one clean suspension
atablefreeofvibrationsanddrafts.Placetheburetsothatitstipisexactly
hook remove a panel from the methanol and hang it in the
300 mm above the panel.The buret contains distilled water and shall have
vapor space above boiling solvent selected in 6.3 for 5 min,
a tip of proper dimensions to deliver 0.05 6 0.01 mLof distilled water per
ensuring that the panel is completely wet with the refluxing
drop.Allowonedropofdistilledwatertofallontothepanelsurface.Ifthe
solvent.
surface is absolutely clean, successive droplets on various parts of the
surface will spread out completely in spots of closely reproducible
NOTE 8—Cleaning the panel with solvent vapors is conveniently done
dimensions. A clean panel should give a spread of 21 to 23 mm for each
using approximately 100 mL of solvent selected in 6.3 in a 400- to
0.05 mLof distilled water.This test is considered necessary and important
600-mLtall-form beaker. Perform this operation in a well-ventilated hood
because of variations found in different abrasive materials and the
and make sure there are no sources of ignition in the area. Heat-resistant
personal factors involved in the
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
An American National Standard
Designation:D1748–00 Designation: D 1748 – 02 (Reapproved 2008)
Designation: 366/84
Standard Test Method for
Rust Protection by Metal Preservatives in the Humidity
Cabinet
This standard is issued under the fixed designation D 1748; 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.
This test method standard has been adoptedapproved for use by government agencies to replace Method5310of the Department of
Federal Test Method Standard No791b. Defense.
1. Scope
1.1This test method is used for evaluating the rust-preventive properties of metal preservatives under conditions of high
humidity.
1.2The values stated in SI units are to be regarded as the standard.
1.1 This test method covers the evaluation of the rust-preventive properties of metal preservatives under conditions of high
humidity.
1.2 The values stated in SI units are to be regarded as the standard except where the test apparatus or consumable parts are only
available in other units. In such cases these will be regarded as standard. The values given in parentheses are for information only.
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 consult and establish appropriate safety and health practices and determine the applicability of
regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
A 109/A 109M Specification for Steel, Strip, Carbon, Cold-Rolled Specification for Steel, Strip, Carbon (0.25 Maximum
Percent), Cold-Rolled
D 512 Test Methods for Chloride Ion inIn Water
D 516 Test Method for Sulfate Ion in Water
E 11Specification for Wire-Cloth Sieves for testing Purposes Specification for Wire Cloth and Sieves for Testing Purposes
E 323 Specification for Perforated-Plate Sieves for testingTesting Purposes
2.2 Federal Standards:
QQ-S-698 Steel Sheet and Strip, Low Carbon
2.3 Military Standards:
MIL-C-5646F Cloth, Airplane
MIL-C-15074E Corrosive Preventive Compound Finger Print Remover
2.4 Society of Automotive Engineers:
SAE 1009C Tee Reducer, Bulkhead on Side, Flareless Tube
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.L0.03
on Corrosion Testing of Sheet Metal Processing Fluids.
´1
Current edition approved Dec. 10, 2000. Published February 2001. Originally published as D1748–60T. Last previous edition D1748–83 (1993) .
Current edition approved May 1, 2008. Published July 2008. Originally approved in 1960. Last previous edition approved in 2002 as D 1748–02.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 01.03.volume information, refer to the standard’s Document Summary page on the ASTM website.
Annual Book of ASTM Standards, Vol 11.01.
Available from Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.
Annual Book of ASTM Standards, Vol 14.02.
Available from Standardization Documents Order Desk, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Available from Superintendent of Documents, U. S. Government Printing Office, Washington, D.C. 20402.
Available from Society of Automotive Engineers, 400 Commonwealth Dr., Warrendale, PA 15096.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 1748 – 02 (2008)
3. Summary of Test Method
3.1 Steel panels are prepared to a prescribed surface finish, dipped in the test oil, allowed to drain, and then suspended in a
humidity cabinet at 48.9 6 °C48.9°C (120°F) for a specified number of hours. The oil fails or passes the test in accordance with
the size and number of rust dots on the test surfaces of the panels.
4. Significance and Use
4.1 Thistestmethodisusedformeasuringtherelativeabilitiesofmetalpreservativestopreventtherustingofsteelpanelsunder
conditionsofhighhumidity.Itshouldnotbereliedupontopredicttheeffectivenessofametalpreservativeinwhichhighhumidity
is not the principal factor in the rusting.
4.2There are published data indicating a useful degree of correlation with service performance, though these data are not
extensive. Comparisons 4.2 Comparisons made by this test method should normally be limited to similar metal preservative
combinations designed for similar applications. The test life required for each type of metal preservative and for each intended
application should be based on actual experience with that type of preservative in the intended service.
4.3 Since the precision of the test method appears to be less than desired, a number of repeat tests may be necessary to establish
the test life of a given metal preservative, and repeat tests by this test method in more than one cabinet are sometimes desirable.
D 1748 – 02 (2008)
4.4 The data obtained from this accelerated test is of interest only in eliminating the most unsuitable materials or for indicating
a probable relative order of protection against rust under conditions of high humidity. This test method does not prescribe the
exposure periods to be used for a specific product, nor the interpretation to be given to the results.
5. Apparatus
5.1 The apparatus shall conform to the details shown in the Annex A1.
6. Panel Cleaning Materials
6.1 Aluminum Oxide Cloth, 240-grit.
NOTE 1—Paper-backed abrasives, wet or dry, waterproof, or iron oxide abrasives are prohibited.
6.2 Silica Sand, white, dry, sharp, chloride free, or aluminum oxide, blasting grade. (The size shall be such that it meets the
following sieve requirements of Specifications E 11 and E 323.
6.2.1 One hundred percent must pass through a No. 10 (2.00-mm) sieve.
6.2.2 Minimum of 90 % must pass through a No. 20 (850-µm) sieve.
6.2.3 Maximum of 10 % permitted to pass through a No. 50 (300-µm) sieve.
6.3 Solvent, safe, non-filming, non-chlorinated. (Naphtha, petroleum naphtha, precipitation naphtha, and methanol were
formerly selected as solvents to be used in this test method but have been eliminated due to possible toxic effects. Each user shall
select a solvent that can meet applicable safety standards and that can thoroughly clean all parts.) Cleaners—Select a cleaning
media and method, which is safe, non-film forming and which does not in any way attack or etch the surface chemically. In
addition, no Class 1 ozone depleting substances conforming to Section 602(a) of the Clean Air Act Amendments of 1990
(42USC7671a)asidentifiedinSection326ofPL102-484shouldbeused.UseaprocedureasoutlinedinTestMethodF 22tojudge
the merit of the selected cleaning technique.
NOTE 2—A typical solvent found acceptable for this purpose is hexane or Stoddard solvent.
NOTE 3—The original precision was developed using a combination of petroleum naphtha and methanol. These are no longer used due to toxicity
issues.
6.4 Gauze, lint free cotton or gauze pads.
7. Humidity Cabinet Operating Conditions
7.1 During evaluation of a sample the cabinet shall be run continuously with the following standard conditions being
maintained:
Air temperature:
Inside the cabinet 48.9 6 1.1°C (120 6 2°F)
Inside the cabinet 48.9 6 1.1°C (120 6 2.0°F)
Outside the cabinet 24.1 6 5.5°C (75 6 10°F)
Outside the cabinet 24.1 6 5.5°C (75.4 6 10.0°F)
Rate of air to the cabinet
0.878(31 6 1ft /h) at 25°C and 760
Rate of air to the cabinet
0.878 6 0.028 m /h) at 25°C and
6 0.028 m /h mm Hg
3 3
6 0.028 m /h (31.0 6 1ft /h) at 25.0°C and
760 mm Hg
Water in cabinet:
Level 203 6 6.4mm(8 6 ⁄4 in.)
Level 203.0 6 6.4mm(8.0 6 ⁄4 in.)
pH 5.5to7.5
Oil content clear with no evidence of oil
Chlorides less than 20 ppm (Test Method
D 512)
Chlorides less than 20 ppm (Test Methods
D 512)
A
Sulfates and sulfites less than 20 ppm as sulfate (Test
Method D 516) A Boil the water sample
with 10 mL of saturated bromine water
before making the test for sulfates.
Speed of rotating 0.33 6 0.03 rpm
Cover close fitting
Cloth layers in cover shall not be torn, contaminated,
nor contain droplets of water
Cover opening to a height of 355 mm (14 in.) at
the front
D 1748 – 02 (2008)
A
Boil the water sample with 10 mL of saturated bromine water before making the test for sulfates.
7.2 Rate of air to the cabinet, air temperature, pH, and water level shall be checked and regulated if necessary in the morning
and afternoon of each day.twice each day, at 7- to 8-h intervals. Remaining standard conditions shall be closely checked once each
week. The pH measurement may be made with wide-range indicator paper.
NOTE2—Values 4—Values for pH outside the limits shown indicate contamination that should be investigated and corrected.Apersistent low pH along
with a positive sulfate test indicates that the air supply is contaminated with sulfur oxides. In this case, the water in the cabinet should be replaced, and
a suitable alkali scrubber system installed in the air train.
NOTE 35—Detailsofthecabinetoperationdescribedin7.1and7.2andthedetailsofpanelpreparationdescribedinSection8,mustbecarefullycarried
out. Only by such standardization can results be obtained that are significant and comparable to those run at another time or in another laboratory.
8. Panel Preparation
8.1 Remove the protective packaging from all the panels to be used for a particular day and wash away the rust preventive
materialinabeakerofsolventselectedin6.3(swabbingispermissibleusingmaterialsdefinedin6.4).Carefullyinspecteachpanel
and use only those which comply with requirements given in Annex A1.10. Identify each panel by an appropriate number in the
right-hand lower corner, outside of the significant area, or by attaching a small metal tag to the outside wire hook after the panel
is polished.
8.2 The following are pertinent to the polishing operations:
8.2.1 Do not allow the bare fingers to touch the panel. Tongs, metal hooks, or pieces of lint-free paper are suitable helpers for
manipulating and holding the panel.
8.2.2 Always keep the panel on a clean, dry surface.
8.3 Alternative Surface Finishes—Polishing :
8.3.1 The amount of polishing of the panel by the operator conducting the humidity cabinet test should only be that required
to give it a fresh, clean, and active surface. This requires only a few minutes per panel. A fast-moving belt sander should not be
usedsincetheheatoffrictionmaychangethesurfacecharacteristicsofthepanel.Surfacefinishlimitsforthepanelarenotdefined
here. There should be no appreciable change of the finish from the 0.25 to 0.51 µm (10 to 20 µm) obtained by the original surface
grinding A1.10.1.3.
8.3.2 Divide the 240-grit aluminum oxide abrasive cloth into convenient size strips for the subsequent polishing operations.
Observing the precautions given in 8.2 and 8.3, buff all four of the rounded edges with even strokes in the direction of each edge.
Ream out the two holes used for suspension and wipe clean, using gauze wet with solvent selected in 6.3.
8.3.3 While polishing, place the panel on a clean, dry surface with a suitable thickness of clean paper under it to help prevent
contamination. The panel may be held by hand, using paper between the fingers and the steel surface.Alternatively it may be held
in a special holder such as a wooden block, having about a 1.6-mm ( ⁄16-in.) depression slightly larger in area than the 51- by
102-mm (2- by 4-in.) dimension of the panel. The abrasive cloth may be held in the palm of the hand with the fingers applying
pressuretothepanel.Alternatively,thealuminumoxideclothmaybeheldonablockofsizeconvenienttothehandandconvenient
for polishing with smooth strokes without marking the ends of the panel.
8.3.4 Polish the unnumbered or leading surface of the panel with careful even strokes, always parallel to the 102-mm (4.0-in.)
dimension. Use a polishing pressure of about 4.5 to 8.9 N (1.0 to 2.0 lb). Do not scratch the surface by using short or curved
strokes. Ensure that the panel is held firmly so that only the abrasive cloth moves. After several polishing strokes, inspect the
abrasive cloth and when necessary make another fold to expose a new and effective area. Continue to polish the leading surface
until it contains a completely fresh surface.The finish should be within the range from 0.25 to 0.51 µm (10(9.8 to 20.0 µin.) (rms).
Examine the entire surface, and if scratches or other imperfections are noted, continue polishing until corrected. In the same
manner polish the second side of the panel, unless the test specification requires only one polished side per panel.
NOTE4—It 6—Itisadvisableforeachoperatortofinishseveralpanelstodetermineexactlywhattechniqueisrequiredtoattainthecorrectsurfacefinish
using a profilometer or other surface roughness gage. After techniques have been established, the use of visual comparison standards is sufficient as a
check on surface roughness.
8.3.5 Remove the dust from the abrasive operation, using clean gauze wet with solvent selected in 6.3. Finally, wipe with clean
surgical gauze until there is no dark stain on a clean section of the gauze. Remove any dust in the holes by use of a pipe cleaner.
(Thismaybefollowedbyanultrasoniccleaningbathprocedure.)Submergethepanelcompletelyinsolventselectedin6.3atroom
temperature.
NOTE5—The 7—The following should be carried out periodically as a check on surface cleanliness: Place the cleaned panel directly under a buret on
a table free of vibrations and drafts. Place the buret so that its tip is exactly 300 mm above the panel. The buret contains distilled water and shall have
a tip of proper dimensions to deliver 0.05 6 0.01 mL of distilled water per drop. Allow one drop of distilled water to fall onto the panel surface. If the
surface is absolutely clean, successive droplets on various parts of the surface will spread out completely in spots of closely reproducible dimensions.
A clean panel should give a spread of 21 to 23 mm for each 0.05 mL of distilled water. This test is considered necessary and important because of
variations found in different abrasive materials and the personal factors involved in the
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