ASTM D7087-05

Standard Test Method for An Imaging Technique to Measure Rust Creepage at Scribe on Coated Test Panels Subjected to Corrosive Environments

SCOPE
1.1 This test method covers the measurement of rust creepage area from a scribe line on painted/coated flat test panels after exposure to corrosive environments. This test method has the advantage of simplicity and ease of use. Expensive equipment is not required, and the results are more accurate than visual evaluation but not as precise as advanced digital imaging.
1.2 This test method uses visual imaging software to determine the area damaged by rust creepage from the scribe.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2005
• ICS: 77.060 - Corrosion of metals
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.25 - Evaluation of Weathering Effects

Relations

• Replaced By: ASTM D7087-05a - Standard Test Method for An Imaging Technique to Measure Rust Creepage at Scribe on Coated Test Panels Subjected to Corrosive Environments
• Effective Date: 01-Jul-2005
• Referred By: ASTM D1654-08(2016)e1 - Standard Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments
• Effective Date: 01-Apr-2005

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D7087–05
Standard Test Method for
An Imaging Technique to Measure Rust Creepage at Scribe
on Coated Test Panels Subjected to Corrosive
Environments
This standard is issued under the fixed designation D 7087; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 6695 Practice for Xenon-Arc Exposures of Paint and
Related Coatings
1.1 This test method covers the measurement of rust creep-
G85 Practice for Modified Salt Spray (Fog) Testing
age area from a scribe line on painted/coated flat test panels
after exposure to corrosive environments. This test method has
3. Significance and Use
the advantage of simplicity and ease of use. Expensive equip-
3.1 This test method provides a means of evaluating and
ment is not required, and the results are more accurate than
comparing development of corrosion at scribe on painted/
visual evaluation but not as precise as advanced digital
coated flat test panels after exposure to corrosive environ-
imaging.
ments.
1.2 This test method uses visual imaging software to deter-
mine the area damaged by rust creepage from the scribe.
4. Apparatus
1.3 The values stated in SI units are to be regarded as the
4.1 Transparent Plastic Sheet—Use transparent plastic
standard. The values given in parentheses are for information
sheet with thickness approximately 0.085 mm (0.0034 in. or
only.
3.4 mil). The sheet material must be transparent enough for
1.4 This standard does not purport to address all of the
easy tracing and must be sufficiently absorbent to provide good
safety concerns, if any, associated with its use. It is the
ink adhesion.
responsibility of the user of this standard to establish appro-
4.2 Tracing Pen—A black permanent marker with ultrafine
priate safety and health practices and determine the applica-
tip approximately 0.5 mm (0.02 in.) in diameter.
bility of regulatory limitations prior to use.
4.3 Ruler—Any transparent ruler with 1-mm black divi-
sions.Thislengthshallbeshorterthaneitherlengthorwidthof
2. Referenced Documents
2 glass surface of scanner.
2.1 ASTM Standards:
4.4 Computer and Scanning System—Any computer and
B117 Practice for Operating Salt Spray (Fog) Apparatus
compatible scanning system is applicable. A computer with at
D 1014 Practice for Conducting Exterior Exposure Tests of
least32MBofRAMisrecommended. Aflatbedscannerwith
Paints and Coatings on Metal Substrates
1200 dpi optical, 120032400 dpi hardware resolution is
D 1654 Test Method for Evaluation of Painted or Coated
suggested.The scanner must have a feature where it selects the
Specimens Subjected to Corrosive Environments
bestpossibleresolutionrequiredforscanning.Thereisnoneed
D 4585 Practice for Testing Water Resistance of Coatings
to calibrate or change settings while scanning.
Using Controlled Condensation
4.5 Image Software—Use any image software capable of
D 4587 Practice for Fluorescent UV-Condensation Expo-
reading an image file generated from the computer and
sure of Paint and Related Coatings
scanning system, calibrating length, and integrating area rap-
D 5894 Practice for Cyclic Salt Fog/UV Exposure of
idly and accurately.
Painted Metal, (Alternating Exposures in a Fog/Dry Cabi-
net and a UV/Condensation Cabinet)
5. Specimen Scribing
5.1 Scribe test specimens in accordance with Test Method
D 1654, section on Preliminary Treatment of Test Specimens.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
The panels should be scribed in a single straight line.
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.25 on Evaluation of Weathering Effects.
Current edition approved April 1, 2005. Published April 2005.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The transparent plastic sheet material of one-gallon size zipper freezer bag
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM without surface texture was found acceptable in round robin testing.
Standards volume information, refer to the standard’s Document Summary page on APC compatible computer with the Windows 95, Windows 98, Windows ME,
the ASTM website. Windows NT, Windows 2000 or Windows XP operating system is applicable.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7087–05
6. Exposure of Test Specimens of the scribe. Ensure that the plastic does not move during the
rotation. Make sure the traced lines at both ends of scribe line
6.1 Prior to exposure, measure the width of the scribe.
are connected.The traced line must have uniform intensity and
Record this information.
good continuity.
6.2 Expose test specimens in accordance with any of the
(b) On the plastic sheet, mark points i, j, k, and l on the
following PracticesB117, D 1014, D 4585, D 4587, D 5894,
outside edge of the traced line.Atypical trace of creepage area
D 6695, and G85, or any other applicable test method, as
developed around the scribe line (ab) and marking points i, j,
agreed upon between the producer and the user. The exposure
k, and l for area integration are shown in Fig. 1. Note that
cycle, length of test and evaluation intervals shall be agreed
scribe line ab should not be traced. Remove the plastic sheet
upon prior to exposure of specimens.
from the panel. With the tracing pen, use a ruler to draw lines
7. Procedure – Evaluation of Scribed Specimens cd and ef on the plastic sheet.
7.1 Prepare Specimens for Evaluation—Prepare the scribed
NOTE 1—Stain beyond the creepage area should not be traced.
specimens in accordance with Test Method D 1654.
NOTE 2—The tracing must be conducted carefully under good light
7.2 Quantification—Quantify the corrosion or loss of paint
condition and by an operator with good eyesight.
extending from a scribe mark, that is, manual tracing followed
NOTE 3—The intensity and continuity of traced line may be examined
by an imaging analysis.
with a magnifying glass or an optical microscope.
7.2.1 Creepage Area Tracing Technique—Trace the rust
NOTE 4—For some people, orienting the panel with scribe line hori-
zontallymaybeeasier.Tracethebottomsideofthecreepageareafirstand
creepage area based on the procedure described in 7.2.1.1 and
then trace the topside of creepage area later. Make sure the traced lines at
7.2.1.2.
both ends of the scribe line are connected.
7.2.1.1 Marking Test Specimen—Place the ruler immedi-
ately below and parallel to the scribe line ab of the test panel
7.2.2 Trace Scanning—Place the transparent plastic sheet
(refer to Fig. 1 for geometry terms). Use the tracing pen to
with the traced creepage or undercutting area with marked
mark points g and h on the test panel so that gh is the center
points i, j, k, and l and lines cd and ef onto the glass of the
line that represents 80 % of the scribe line. Mark points i, j, k,
flatbed scanner. Place a ruler next to the trace area with the
and l with the pen on the borderline of creepage area such that
dimension markings facing the light source. Back the tracing
lines ig and kh are perpendicular to the scribe line (See Fig. 1).
and the ruler with a sheet of white paper or cardstock. Scan the
Remove the ruler.
image that must include all the traced line and the ruler. Save
7.2.1.2 Area Tracing—Place a single sheet of the transpar-
this image as a .xxx file in the computer with a unique
ent plastic that is 50 % larger than the panel over the entire
filename.
corroded side of the scribed panel. Do not stretch the plastic
7.2.3 Imaging and Integrating Creepage Area—Use image
sheet and ensure there are no folds or creases. Press the sheet
software capable of capturing and opening image file of trace.
tightly against the panel and fold the excess around the back of
Calibrate distance by selecting a known length with the ruler
the panel. To av
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