ASTM D6958-03(2014)

Standard Test Methods for Evaluating Side-Bonding Potential of Wood Coatings

SIGNIFICANCE AND USE
4.1 This test method was originally designed as a means of quantitatively measuring the level of adhesion of the wood-wood interface caused by a wood coatings system applied to the substrate. The tensile test is useful in measuring bonding strength of coatings, such as gymnasium coatings, in which the wood strip flooring primarily expands or contracts in response to changes across the cross-sectional width of the strip floor.  
4.2 This test method was further designed as a means of measuring the side-bonding potential of wood coating systems.
SCOPE
1.1 These test methods describe an evaluation procedure for the determination of undesirable side-bonding of coatings for wood flooring. They provide two mechanical properties tests for the quantitative determination of the cohesive strength of wood coatings (tensile and lap shear); they also provide a wood floor simulation test for the qualitative determination of side-bonding potential of wood coatings.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
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 establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Jul-2014
• ICS: 79.080 - Semi-manufactures of timber
• Technical Committee: D07 - Wood
• Drafting Committee: D07.01 - Fundamental Test Methods and Properties

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D6958 − 03 (Reapproved 2014)
Standard Test Methods for
Evaluating Side-Bonding Potential of Wood Coatings
This standard is issued under the fixed designation D6958; 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.
1. Scope 2.3 Maple Flooring Manufacturers Association (MFMA):
Guide Specification for Double Plywood Floor System
1.1 These test methods describe an evaluation procedure for
Guide Specification for Sleeper and Sleeper with Plywood
the determination of undesirable side-bonding of coatings for
Floor Systems
wood flooring. They provide two mechanical properties tests
for the quantitative determination of the cohesive strength of 2.4 Wood Flooring Manufacturers Association (NOFMA):
woodcoatings(tensileandlapshear);theyalsoprovideawood Cracks in Hardwood Floors
floor simulation test for the qualitative determination of side- 6
2.5 National Wood Flooring Association (NWFA):
bonding potential of wood coatings.
Hardwood Floors Trouble Shooting Manual
1.2 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical
3. Terminology
conversions to SI units that are provided for information only
3.1 Definitions:
and are not considered standard.
3.1.1 Definitions used in these test methods are in accor-
1.3 This standard does not purport to address all of the
dance with terminology used inTerminology D9.Afew related
safety concerns, if any, associated with its use. It is the
terms not covered in these test methods are as follows:
responsibility of the user of this standard to establish appro-
3.1.2 panelization—adjacent boards acting as a composite
priate safety and health practices and determine the applica-
panel instead of individual strips when subjected to changes in
bility of regulatory limitations prior to use.
temperature and humidity as well as other site conditions.
3.1.3 panelization failure—the condition where localized
2. Referenced Documents
excessive gaps beyond specified limits develop between some
2.1 ASTM Standards:
strip flooring boards due to panelization.
D9 Terminology Relating to Wood and Wood-Based Prod-
3.1.4 percent wood failure—the rupturing of wood fibers in
ucts
strength tests on bonded specimens usually expressed as the
D2370 Test Method for Tensile Properties of Organic Coat-
percentage of total area involved, which shows such failure.
ings
The inverse of adhesive failure.
D4444 Test Method for Laboratory Standardization and
Calibration of Hand-Held Moisture Meters 3.1.5 side-bonding—the bonding of adjacent strips of wood
flooring caused by the floor coating resulting in panelization.
2.2 British Standards:
B.S. 1204 British Standard Test for Synthetic Resin Adhe- This is one possible cause of panelization failure.
sives
3.1.6 side-bonding wood failure—the failure of the wood
within a strip, as in classic wood failure, when the movement
of the strip within the floor is restrained from moisture-related
movement by excessive side-bonding. In this situation, the
toughness or “work-to-break” of the side-bonding is sufficient
to overcome the tensile strength perpendicular to the grain of
These test methods are under the jurisdiction of ASTM Committee D07 on
the wood strip.
Wood and are the direct responsibility of Subcommittee D07.01 on Fundamental
Test Methods and Properties.
Current edition approved Aug. 1, 2014. Published August 2014. Originally
approved in 2003. Last previous edition approved in 2009 as D6958 – 03 (2009).
DOI: 10.1520/D6958-03R14. Available from the Maple Flooring Manufacturers Association, Inc. (MFMA),
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 111 Deer Lake Road, Suite 100, Deerfield, IL 60015, http://www.maplefloor.org.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from the Wood Flooring Manufacturers Association (NOFMA),
Standards volume information, refer to the standard’s Document Summary page on formerly known as the National Oak Flooring Manufacturers Association, 22 N.
the ASTM website. Front Street, Suite 1080, Memphis, TN 38103, http://www.nofma.org.
3 6
Available from British Standards Institute (BSI), 389 Chiswick High Rd., Available from the National Wood Flooring Association (NWFA), 111 Ches-
London W4 4AL, U.K., http://www.bsi-global.com. terfield Industrial Boulevard, Chesterfield, MO 63005, http://www.woodfloors.org
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6958 − 03 (2014)
3.1.7 tensile stress (nominal)—as used in Test Method 6.5 Test assemblies consist of two test blocks “edge-glued”
D2370,theloadperoriginalunitareaatwhichaspecimenfails using the floor coating as an adhesive (see Fig. 1). The coating
or yields in a tension (pull) test. to be evaluated shall be applied using a polybrush to the
smooth edge of both test blocks at a rate of 500 65ft /gal
(12.3 6 0.1 m /L) or as specified by the coating manufacturer.
SECTION I—MECHANICAL PROPERTIES TESTS
After a 5 min open time the test block pairs shall be assembled
by placing the coated surfaces together and clamping the joint
TEST METHOD A—MAPLE BLOCK TENSILE
at 100 psi (690 kPa) pressure. Test assemblies shall remain
STRENGTH TEST
clamped for a minimum of 48 h.
4. Significance and Use
6.6 Test assemblies shall be cured at 75 6 5°F (24 6 3°C)
and 50 6 2 % relative humidity for a minimum of seven days
4.1 This test method was originally designed as a means of
including the clamp time. After equilibrating, use a moisture
quantitatively measuring the level of adhesion of the wood-
meter to determine the EMC of all test assemblies, and
wood interface caused by a wood coatings system applied to
calculate the average EMC.
the substrate. The tensile test is useful in measuring bonding
strength of coatings, such as gymnasium coatings, in which the
6.7 Measure and record the length and width of the test
wood strip flooring primarily expands or contracts in response assembly to the nearest 0.01 in. (0.3 mm). Calculate the test
to changes across the cross-sectional width of the strip floor.
area of each test assembly.
4.2 This test method was further designed as a means of 6.8 Test assemblies shall be secured in a test machine (see
measuring the side-bonding potential of wood coating systems.
Fig. 2) and pulled apart in tension at a rate of 0.1 in./min (2.54
mm/min).
5. Apparatus
6.9 Record the ultimate load, location of failure (coating-
5.1 Tensile Tester, of the constant rate of jaw separation coating interface, coating-wood interface, within wood), an
type, equipped with load cells having capacities of 100 to 1000 estimate of the percent wood failure and the average EMC.
lb (445 to 4452 N), and equipped with an indicating device
7. Report
such as an electronic constant speed chart recorder, a digital
device that displays numerical values, or a printer that records
7.1 Report the number of samples tested, the location of
the numerical values and suitably sized grips to hold the test
failure (coating-coating interface, coating-wood interface,
specimens in place during testing. The machine must be
within wood), an estimate of the percent wood failure, and the
capable of maintaining a cross head velocity during testing of
average EMC.
0.1 in./min (2.54 mm/min), and if using a strip chart recorder,
8. Precision and Bias
a chart speed during testing of 10 in./min (254 mm/min).
8.1 Until sufficient data are available as a result of perform-
5.2 Clamp Assembly, capable of holding assembled test
ing these tests, no specific precision and bias statement can be
specimen and maintaining a clamp pressure of 100 psi (690
expressed.
kPa).
5.3 Moisture Meter, meeting the requirements of Test
TEST METHOD B—MAPLE STRIP LAP SHEAR TEST
Method D4444.
9. Significance and Use
5.4 Foam Polybrushes, 1 in. (25.4 mm) wide.
9.1 This test method was originally designed as a means of
quantitatively measuring the level of adhesion of the wood-
6. Procedure
woodbondinterfacecausedbyawoodcoatingssystemapplied
6.1 Material for testing shall be #2 or better, MFMA
to the substrate. The lap shear test is useful for measuring
certified hard maple (Acer saccharum) tongue and groove strip
bonding strength of coatings used on parquet or other similar
1 25
flooring, 2 ⁄4 6 0.03 in. (57.2 6 0.8 mm) in width by ⁄32 6
types of flooring, where longitudinal movement of the flooring
0.01 in. (19.8 6 0.3 mm) in thickness.
is a concern (for example, the shear force as the individual
6.2 Test stock shall be prepared by cutting off the tongue
wood pieces slide past each other).
and planing the edge smooth. Blocks for testing shall be cut to
9.2 This test method was further designed as a means of
a length of 3.00 6 0.01 in. (76.2 6 0.3 mm).
measuring the side-bonding potential of wood coating systems.
6.3 Test blocks shall be conditioned at 75 6 5°F (24 6 3°C)
and 50 6 2 % relative humidity for a minimum of seven days. 10. Apparatus
These conditions equate to an equilibration moisture content
10.1 Tensile Tester, of the constant rate of jaw separation
(EMC) of ~9 % (see X1.3).After equilibrating, use a moisture
type, equipped with load cells having capacities of 100 to 1000
meter to determine the EMC of all test blocks, calculate and
lb (445 to 4452 N), and equipped with an indicating device
report the average EMC.
such as an electronic constant speed chart recorder, a digital
6.4 A minimum of twenty test blocks shall be used to device that displays numerical values, or a printer that records
prepare a minimum of ten assemblies for testing of each the numerical values as well as suitably sized grips to hold the
coating to be evaluated (see Fig. 1). test specimens in place during testing. The machine must be
D6958 − 03 (2014)
FIG. 1 Test Method A, Maple Block Tensile Strength Test-Test Blocks (top), Test Assembly (bottom)
capable of maintaining a cross head velocity during testing of 11.1.3 A minimum of twenty test strips shall be used to
0.1 in./min (2.54 mm/min), and if using a strip chart recorder prepare a minimum of ten assemblies for testing of each
a chart speed during testing of 10 in./min (254 mm/min). coating to be evaluated (see Fig. 3).
11.1.4 Test assemblies consist of two test strips “face-
10.2 Clamp Assembly, capable of holding assembled test
glued”usingthefloorcoatingasanadhesive.Thecoatingtobe
specimen and maintaining a clamp pressure of 100 psi (690
evaluated shall be applied using a polybrush on a one-inch
kPa).
overlap test area on the ends of the test strips at a rate of 150
10.3 Moisture Meter, meeting the requirements of Test 2 2
65ft /gal (3.7 6 0.1 m /L) or as specified by the coating
Method D4444.
manufacturer (see Fig. 3).After a 5 min open time the test strip
10.4 Foam Polybrushes, 1 in. (25.4 mm) wide. pairs shall be assembled by placing the coated surfaces
together and clamping the joint at 100 psi (690 kPa) pressure.
11. Procedure
Test assemblies shall remain clamped for a minimum of 48 h
(see Figs. 4 and 5).
11.1 Material for testing shall be #2 or better, MFMA
11.1.5 Test assemblies shall be cured at 75 6 5°F (24 6
certified hard maple (Acer saccharum) tongue and groove strip
1 25
3°C) and 50 6 2 % relative humidity for a minimum of seven
flooring, 2 ⁄4 6 0.03 in. (57.2 6 0.8 mm) in width by ⁄32 6
days including the clamp time. After equilibrating, use a
0.01 in. (19.8 6 0.3 mm) in thickness.
moisture meter to determine the EMC of all test assemblies,
11.1.1 Test stock shall be prepared by cutting off the tongue
calculate and report the average EMC.
and planing the edge smooth. Strips for testing shall be planed
11.1.6 Measure and record the length and width of the test
from this test stock to a width of 1.0 6 0.01 in. (25.4 6 0.3
area to the nearest 0.01 in. (0.3 mm). Calculate the test area of
mm), a length of 4.5 6 0.01 in. (114 6 0.3 mm) and a
each test assembly.
thickness, 0.125 6 0.006 in. (3.18 6 0.15 mm) (see Appendix
11.1.7 Test assemblies shall be secured in a test machine
X2).
11.1.2 Test strips shall be conditioned at 75 6 5°F (24 6 (see Fig. 2) and pulled apart in tension at a rate of 0.1 in./min
(2.54 mm/min).
3°C) and 50 6 2 % relative humidity for a minimum of seven
days. These conditions equate to an EMC of ~9 % (see X1.3). 11.1.8 Recordtheultimateload,locationoffailure(coating-
Afterequilibrating,useamoisturemetertodeterminetheEMC coating interface, coating-wood interface, within wood), an
of all test strips, and calculate the average EMC. estimate of the percent wood failure and the average EMC.
D6958 − 03 (2014)
FIG. 2 Assembly Secured in Testing Machine
12. Report systems. The flooring simulation test is helpful in giving a
visualizationofthesignificanceofthetensile/lapshearstrength
12.1 Report the number of samples tested, the location of
numbers generated. Dependent on the specific end use of the
failure (coating-coating interface, coating-wood interface,
coating, other flooring types, for example, plank, parquet,
within wood), an estimate of the percent wood failure, the
could also be evaluated under this test method.
average EMC and the average shear strength.
15. Apparatus
13. Precision and Bias
15.1 Moisture Meter, meeting the requirements of Test
13.1 Until sufficient data are available as a result of per-
Method D4444.
forming these analyses, no specific precision and bias require-
ments can be expressed. 15.2 Face Nailing Machine, capable of face nailing 2 in.
(50.8 mm) nail cleats.
15.3 Side Nailing Machine, capable of nailing 2 in. (50.8
SECTION II
mm)nailcleatsintotongueandgroove2 ⁄4in.(57.2mm)wide,
TEST METHOD C—FLOOR SIMULATION TEST
⁄32 in. (19.8 mm) thick, maple strip flooring.
15.4 Foam Polybrushes, 2 in. (50.8 mm) wide.
14. Significance and Use
15.5 120-Grit Sandpaper.
14.1 This test method was designed as a means of qualita-
tively measuring the side-bonding potential of wood coating 15.6 Test Panels, (prepared as described in Section 16).
D6958 − 03 (2014)
FIG. 3 Test Method B, Maple Strip Lap Shear Test-Test Strips (top), Test Assembly (bottom)
FIG. 4 Front View of Clamp Assembly
D6958 − 03 (2014)
FIG. 5 Side View of Clamp Assembly
16. Floor Simulation Test Panels 16.2 Side-Bonding Test Panel Design:
16.2.1 Test panels shall be constructed using two pieces of
16.1 The panel design (see F
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM 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.
Designation: D6958 − 03 (Reapproved 2009) D6958 − 03 (Reapproved 2014)
Standard Test Methods for
Evaluating Side-Bonding Potential of Wood Coatings
This standard is issued under the fixed designation D6958; 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.
1. Scope
1.1 These test methods describe an evaluation procedure for the determination of undesirable side-bonding of coatings for wood
flooring. They provide two mechanical properties tests for the quantitative determination of the cohesive strength of wood coatings
(tensile and lap shear); they also provide a wood floor simulation test for the qualitative determination of side-bonding potential
of wood coatings.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
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 establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D9 Terminology Relating to Wood and Wood-Based Products
D2370 Test Method for Tensile Properties of Organic Coatings
D4444 Test Method for Laboratory Standardization and Calibration of Hand-Held Moisture Meters
2.2 British Standards:
B.S. 1204 British Standard Test for Synthetic Resin Adhesives
These test methods are under the jurisdiction of ASTM Committee D07 on Wood and are the direct responsibility of Subcommittee D07.01 on Fundamental Test Methods
and Properties.
Current edition approved May 1, 2009Aug. 1, 2014. Published June 2009August 2014. Originally approved in 2003. Last previous edition approved in 20032009 as
D6958 – 03.D6958 – 03 (2009). DOI: 10.1520/D6958-03R09.10.1520/D6958-03R14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from British Standards Institute (BSI), 389 Chiswick High Rd., London W4 4AL, U.K., http://www.bsi-global.com.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6958 − 03 (2014)
2.3 Maple Flooring Manufacturers Association (MFMA):
Guide Specification for Double Plywood Floor System
Guide Specification for Sleeper and Sleeper with Plywood Floor Systems
2.4 Wood Flooring Manufacturers Association (NOFMA):
Cracks in Hardwood Floors
2.5 National Wood Flooring Association (NWFA):
Hardwood Floors Trouble Shooting Manual
3. Terminology
3.1 Definitions:
3.1.1 Definitions used in these test methods are in accordance with terminology used in Terminology D9. A few related terms
not covered in these test methods are as follows:
3.1.2 panelization—adjacent boards acting as a composite panel instead of individual strips when subjected to changes in
temperature and humidity as well as other site conditions.
3.1.3 panelization failure—the condition where localized excessive gaps beyond specified limits develop between some strip
flooring boards due to panelization.
3.1.4 percent wood failure—the rupturing of wood fibers in strength tests on bonded specimens usually expressed as the
percentage of total area involved, which shows such failure. The inverse of adhesive failure.
3.1.5 side-bonding—the bonding of adjacent strips of wood flooring caused by the floor coating resulting in panelization. This
is one possible cause of panelization failure.
3.1.6 side-bonding wood failure—the failure of the wood within a strip, as in classic wood failure, when the movement of the
strip within the floor is restrained from moisture-related movement by excessive side-bonding. In this situation, the toughness or
“work-to-break” of the side-bonding is sufficient to overcome the tensile strength perpendicular to the grain of the wood strip.
3.1.7 tensile stress (nominal)—as used in Test Method D2370, the load per original unit area at which a specimen fails or yields
in a tension (pull) test.
SECTION I—MECHANICAL PROPERTIES TESTS
TEST METHOD A—MAPLE BLOCK TENSILE STRENGTH TEST
4. Significance and Use
4.1 This test method was originally designed as a means of quantitatively measuring the level of adhesion of the wood-wood
interface caused by a wood coatings system applied to the substrate. The tensile test is useful in measuring bonding strength of
coatings, such as gymnasium coatings, in which the wood strip flooring primarily expands or contracts in response to changes
across the cross-sectional width of the strip floor.
4.2 This test method was further designed as a means of measuring the side-bonding potential of wood coating systems.
5. Apparatus
5.1 Tensile Tester, of the constant rate of jaw separation type, equipped with load cells having capacities of 100 to 1000 lb (445
to 4452 N), and equipped with an indicating device such as an electronic constant speed chart recorder, a digital device that
displays numerical values, or a printer that records the numerical values and suitably sized grips to hold the test specimens in place
during testing. The machine must be capable of maintaining a cross head velocity during testing of 0.1 in./min (2.54 mm/min) ,
mm/min), and if using a strip chart recorder, a chart speed during testing of 10 in./min (254 mm/min).
5.2 Clamp Assembly, capable of holding assembled test specimen and maintaining a clamp pressure of 100 psi (690 kPa).
5.3 Moisture Meter, meeting the requirements of Test Method D4444.
5.4 Foam Polybrushes, 1 in. (25.4 mm) wide.
6. Procedure
6.1 Material for testing shall be #2 or better, MFMA certified hard maple (Acer saccharum) tongue and groove strip flooring,
1 25
2 ⁄4 6 0.03 in. (57.2 6 0.8 mm) in width by ⁄32 6 0.01 in. (19.8 6 0.3 mm) in thickness.
Available from the Maple Flooring Manufacturers Association, Inc. (MFMA), 111 Deer Lake Road, Suite 100, Deerfield, IL 60015, http://www.maplefloor.org.
Available from the Wood Flooring Manufacturers Association (NOFMA), formerly known as the National Oak Flooring Manufacturers Association, 22 N. Front Street,
Suite 1080, Memphis, TN 38103, http://www.nofma.org.
Available from the National Wood Flooring Association (NWFA), 111 Chesterfield Industrial Boulevard, Chesterfield, MO 63005, http://www.woodfloors.org
D6958 − 03 (2014)
6.2 Test stock shall be prepared by cutting off the tongue and planing the edge smooth. Blocks for testing shall be cut to a length
of 3.00 6 0.01 in. (76.2 6 0.3 mm).
6.3 Test blocks shall be conditioned at 75 6 5°F (24 6 3°C) and 50 6 2 % relative humidity for a minimum of seven days.
These conditions equate to an equilibration moisture content (EMC) of ~9 % (see X1.3). After equilibrating, use a moisture meter
to determine the EMC of all test blocks, calculate and report the average EMC.
6.4 A minimum of twenty test blocks shall be used to prepare a minimum of ten assemblies for testing of each coating to be
evaluated (see Fig. 1).
6.5 Test assemblies consist of two test blocks “edge-glued” using the floor coating as an adhesive (see Fig. 1). The coating to
be evaluated shall be applied using a polybrush to the smooth edge of both test blocks at a rate of 500 6 5 ft /gal (12.3 6 0.1
m /L) or as specified by the coating manufacturer. After a 5 min open time the test block pairs shall be assembled by placing the
coated surfaces together and clamping the joint at 100 psi (690 kPa) pressure. Test assemblies shall remain clamped for a minimum
of 48 h.
6.6 Test assemblies shall be cured at 75 6 5°F (24 6 3°C) and 50 6 2 % relative humidity for a minimum of seven days
including the clamp time. After equilibrating, use a moisture meter to determine the EMC of all test assemblies, and calculate the
average EMC.
6.7 Measure and record the length and width of the test assembly to the nearest 0.01 in. (0.3 mm). Calculate the test area of
each test assembly.
6.8 Test assemblies shall be secured in a test machine (see Fig. 2) and pulled apart in tension at a rate of 0.1 in./min (2.54
mm/min).
6.9 Record the ultimate load, location of failure (coating-coating interface, coating-wood interface, within wood), an estimate
of the percent wood failure and the average EMC.
7. Report
7.1 Report the number of samples tested, the location of failure (coating-coating interface, coating-wood interface, within
wood), an estimate of the percent wood failure, and the average EMC.
FIG. 1 Test Method A, Maple Block Tensile Strength Test-Test Blocks (top), Test Assembly (bottom)
D6958 − 03 (2014)
FIG. 2 Assembly Secured in Testing Machine
8. Precision and Bias
8.1 Until sufficient data are available as a result of performing these tests, no specific precision and bias statement can be
expressed.
TEST METHOD B—MAPLE STRIP LAP SHEAR TEST
9. Significance and Use
9.1 This test method was originally designed as a means of quantitatively measuring the level of adhesion of the wood-wood
bond interface caused by a wood coatings system applied to the substrate. The lap shear test is useful for measuring bonding
strength of coatings used on parquet or other similar types of flooring, where longitudinal movement of the flooring is a concern
(for example, the shear force as the individual wood pieces slide past each other).
9.2 This test method was further designed as a means of measuring the side-bonding potential of wood coating systems.
10. Apparatus
10.1 Tensile Tester, of the constant rate of jaw separation type, equipped with load cells having capacities of 100 to 1000 lb (445
to 4452 N), and equipped with an indicating device such as an electronic constant speed chart recorder, a digital device that
displays numerical values, or a printer that records the numerical values as well as suitably sized grips to hold the test specimens
D6958 − 03 (2014)
in place during testing. The machine must be capable of maintaining a cross head velocity during testing of 0.1 in./min (2.54
mm/min), and if using a strip chart recorder a chart speed during testing of 10 in./min (254 mm/min).
10.2 Clamp Assembly, capable of holding assembled test specimen and maintaining a clamp pressure of 100 psi (690 kPa).
10.3 Moisture Meter, meeting the requirements of Test Method D4444.
10.4 Foam Polybrushes, 1 in. (25.4 mm) wide.
11. Procedure
11.1 Material for testing shall be #2 or better, MFMA certified hard maple (Acer saccharum) tongue and groove strip flooring,
1 25
2 ⁄4 6 0.03 in. (57.2 6 0.8 mm) in width by ⁄32 6 0.01 in. (19.8 6 0.3 mm) in thickness.
11.1.1 Test stock shall be prepared by cutting off the tongue and planing the edge smooth. Strips for testing shall be planed from
this test stock to a width of 1.0 6 0.01 in. (25.4 6 0.3 mm), a length of 4.5 6 0.01 in. (114 6 0.3 mm) and a thickness, 0.125
6 0.006 in. (3.18 6 0.15 mm) (see Appendix X2).
11.1.2 Test strips shall be conditioned at 75 6 5°F (24 6 3°C) and 50 6 2 % relative humidity for a minimum of seven days.
These conditions equate to an EMC of ~9 % (see X1.3). After equilibrating, use a moisture meter to determine the EMC of all test
strips, and calculate the average EMC.
11.1.3 A minimum of twenty test strips shall be used to prepare a minimum of ten assemblies for testing of each coating to be
evaluated (see Fig. 3).
11.1.4 Test assemblies consist of two test strips “face-glued” using the floor coating as an adhesive. The coating to be evaluated
shall be applied using a polybrush on a one-inch overlap test area on the ends of the test strips at a rate of 150 6 5 ft /gal (3.7
6 0.1 m /L) or as specified by the coating manufacturer (see Fig. 3). After a 5 min open time the test strip pairs shall be assembled
by placing the coated surfaces together and clamping the joint at 100 psi (690 kPa) pressure. Test assemblies shall remain clamped
for a minimum of 48 h (see Figs. 4 and 5).
11.1.5 Test assemblies shall be cured at 75 6 5°F (24 6 3°C) and 50 6 2 % relative humidity for a minimum of seven days
including the clamp time. After equilibrating, use a moisture meter to determine the EMC of all test assemblies, calculate and report
the average EMC.
11.1.6 Measure and record the length and width of the test area to the nearest 0.01 in. (0.3 mm). Calculate the test area of each
test assembly.
FIG. 3 Test Method B, Maple Strip Lap Shear Test-Test Strips (top), Test Assembly (bottom)
D6958 − 03 (2014)
FIG. 4 Front View of Clamp Assembly
FIG. 5 Side View of Clamp Assembly
11.1.7 Test assemblies shall be secured in a test machine (see Fig. 2) and pulled apart in tension at a rate of 0.1 in./min (2.54
mm/min).
11.1.8 Record the ultimate load, location of failure (coating-coating interface, coating-wood interface, within wood), an estimate
of the percent wood failure and the average EMC.
12. Report
12.1 Report the number of samples tested, the location of failure (coating-coating interface, coating-wood interface, within
wood), an estimate of the percent wood failure, the average EMC and the average shear strength.
D6958 − 03 (2014)
13. Precision and Bias
13.1 Until sufficient data are available as a result of performing these analyses, no specific precision and bias requirements can
be expressed.
SECTION II
TEST METHOD C—FLOOR SIMULATION TEST
14. Significance and Use
14.1 This test method was designed as a means of qualitatively measuring the side-bonding potential of wood coating systems.
The flooring simulation test is helpful in giving a visualization of the significance of the tensile/lap shear strength numbers
generated. Dependent on the specific end use of the coating, other flooring types, for example, plank, parquet, could also be
evaluated under this test method.
15. Apparatus
15.1 Moisture Meter, meeting the requirements of Test Method D4444.
15.2 Face Nailing Machine, cap
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