Post on 27-May-2018
transcript
International Roof Coatings Conference
Coatings Forensics
For
Roofing
Steven Heinje
Technical Service Manager
Quest Construction Products
July 17, 2012
International Roof Coatings Conference Coatings Forensics for Roofing
The Author: Micro-Bio
Scope & Goals
The Forensic Investigation Nature and Dynamics
Science & Presentation
Failure Risk Model
Defect Occurrence Model
Pattern Recognition
Field Tests Moisture Survey
Sampling
Methods Performance
Descriptive
Case Study
Field Flow Chart
Analytical Methods
“Finger Print” methods
Photomicroscopy Digital Image Processing
Laboratory Flow Chart
Resources
Questions
Outline
Micro-Bio
International Roof Coatings Conference Coatings Forensics for Roofing
Education: Bachelorette in Biology/Chemistry („83)
MBA (‟11)
Work: United Coatings/QCP Mfg. for >28 years Primary Roles:
Product Development (esp. Formulation)
Management & Environmental
Codes, Regulation, Standards
Industry and Advocacy ASTM, RCMA, RRCI, RCI, ACS, NPCA, ASQ
V.P. of RCMA
Treasurer of Inland Northwest ACS
Scope of Forensics
International Roof Coatings Conference Coatings Forensics for Roofing
Service Life Prediction
& Material Science
Early Failures
Reverse Engineering
Building Science
Early Failures
International Roof Coatings Conference Coatings Forensics for Roofing
Jonathon W. Martin, A Systems Approach to Service Life Prediction Problems for Coatings Systems,
ACS Series 722, NIST, 1999
A C
B
Region A: Early Failures
Mostly installation, less often Material Defects,
sometimes “Lack of Robustness”.
Region B: Random Failures
Region C:
Wearing Out, Capability
The Forensic Investigation
International Roof Coatings Conference Coatings Forensics for Roofing
Nature and Dynamics
Similar to Litigation:
a solution/settlement is the goal, not blame/science
Root cause is often known by one stakeholder
Appearing to have a vigorous defense is key
Science & Presentation
Be professional, but not erudite
Burn no bridges, and avoid prognostications on job site
The Forensic Investigation
International Roof Coatings Conference Coatings Forensics for Roofing
The stakeholders have biases that
are not data-based
Our products are sight manufactured
- We have a built-in credibility
problem
There are far more variables with
coatings than with prepared roofing
- We carry a high burden of proof
Failure Risk Model
International Roof Coatings Conference Coatings Forensics for Roofing
J.M. Juran, Quality Control Handbook, 3rd edition; 1979
Failure
Risk
Model
International Roof Coatings Conference Coatings Forensics for Roofing
Category Factor Varia t ion (2d)
Solids (SBV) +/- 2%
Resin (PVC) +/- 2/3% (depends on metering)
Color +/- 1%
Air Entrainment +/- 3% (in >120KU “latex” mastics)
Overa ll +/- 5%
Adhesion Overa ll +/- 20% min
1 coat +/- 10% / coat
Overa ll: 3
coa t s
+/- 17% or less (cross ha t ch ing
mit iga t es)
Solar/HeatUp to 100% as temperature, but possibly
3200% from a kinetics perspective
Solar/UV Up to 100%, typically less
Moisture
Often low, <10% in open areas/low slope;
but in steep slope/prevailing wind over
100%
AbrasionFollows wind turbulence dynamics, over
100%.
Overa ll 173%
Substrate
surface cohesive
strength
>200% on wood; >100% on concrete;
<50% on polymeric's
Trapped water 10X [1000%] or much higher
Overa ll ~10X [1000%]
Coat ing
Materia l
Physica l and
Flu id
Propert ies
DFT
Weather
Prepara t ion
Defect Occurrence Model
International Roof Coatings Conference Coatings Forensics for Roofing
Under cured sealant over leak
Leading to blisters
Poor Workmanship
Blisters
Photos courtesy of CFS
Pattern Recognition
International Roof Coatings Conference Coatings Forensics for Roofing
Chalk: North/South Light Corrosion: Random Crack: DFT
Crack: Right vs. Left…
Preparation: Contaminants
on substrate
What was root cause?
Pattern Recognition
International Roof Coatings Conference Coatings Forensics for Roofing
1. Job was done in marginal/cold weather
2. Tint was done by “new guy”
3. Wrong colorant slowed cure and hurt adhesion
4. Potentially exposed to freezing due to long cure cycle
International Roof Coatings Conference Coatings Forensics for Roofing
The Author: Micro-Bio
Scope & Goals
The Forensic Investigation Nature and Dynamics
Science & Presentation
Failure Risk Model
Defect Occurrence Model
Pattern Recognition
Field Tests Moisture Survey
Sampling
Methods Performance
Descriptive
Case Study
Field Flow Chart
Analytical Methods
“Finger Print” methods
Photomicroscopy Digital Image Processing
Laboratory Flow Chart
Resources
Questions
Outline: Field Tests
Moisture Survey
International Roof Coatings Conference Coatings Forensics for Roofing
Scan with NDT methods: Direction/Wind/Shade
Biological growth
Plaster/Wood moisture meter
Tramex (Impedance)
NIR
Probe wet areas to substrate Delmhorst (Conductivity)
Probe various depths
Cores Bag cores quickly
Attics/ceilings (vapor drive)
Interior Moisture (bath/shower)
Recently insulated roof
prior to 4th coat of paint blistering
Pattern Recognition
International Roof Coatings Conference Coatings Forensics for Roofing
Chalk Light Corrosion DFT
Right vs. Left…
Contaminants
on substrate
Other Observations:
•100% No peeling on verticals
•~80% on South
•Really wet and cold!
Pattern Recognition
International Roof Coatings Conference Coatings Forensics for Roofing
Other Observations:
100%: No peeling on verticals
~70%: on South only
Its really green here!
Fairly uniform
Find a new metal area on north that peels/cracks too
0.21 correlation follows spray practice (edge)
High DFT is bad?
Chalks on wet/cold [south/lake] side?
Moisture Survey
International Roof Coatings Conference Coatings Forensics for Roofing
N
Wind
1
2
3 4
5 6
7
8
9
10
Moisture Survey
International Roof Coatings Conference Coatings Forensics for Roofing
1
2 3
11
12
14
SPF
11A
11B
11C
Moisture Survey
International Roof Coatings Conference Coatings Forensics for Roofing
0%
5% 4%
10%
2%
4%
SPF
12%
7%
3%
Conclusion:
Leak around protrusion- failed
flashing?
Only 6 small holes in roof
Sampling
International Roof Coatings Conference Coatings Forensics for Roofing
1
2
3 4
5
1
2
9
6
8
7
10
11
12
13
Determine
failed flashing
is not cause.
Explore DFT
and find a
problem!
Take enough
samples to
build a
correlation for
DFT to
moisture:
13 holes
Sales Rep’ Sampling
Methodology
International Roof Coatings Conference Coatings Forensics for Roofing
Performance Field Test Methods
International Roof Coatings Conference Coatings Forensics for Roofing
Tape Adhesion
Peel Adhesion
Reverse D471 “swell” D-903 Peel Adhesion
Bagged Wet sample
Loss-on-Dry Analyzer
Descriptive Field Tests
International Roof Coatings Conference Coatings Forensics for Roofing
DFT (ASTM D4138) Micrometers tend to give
higher results than actual
Macro Photography
Camera: Nikon D-90;
Lens: Micro Nikkor85mm
1:2.5G ED
Illumination: Natural Daylight
Descriptive Field Tests
International Roof Coatings Conference Coatings Forensics for Roofing
Microscopy (Finescale/Field Microscope)
Sampling Exudate Swabs
Syringe
Watch Glass
Stereo microscope:
A “sun-boiled” coating
(40X)
Micrometers
over state
DFT
Field Tests: Case Study
International Roof Coatings Conference Coatings Forensics for Roofing
Gardco Tape Adhesion Kit
Pfund WFT Gauge
Finescale Comparator
Coring Tool
Photo Backpack
Gardco Tape Adhesion Kit
Cutting Tools
Hotcake WFT Gauge
Replacement Insulation Cores
Field Tests: Case Study
International Roof Coatings Conference Coatings Forensics for Roofing
Droppers
DFT (magnetic)
Sharpies
Moisture Meter
Loupe
Tripod
Sampling supplies
Thermo/Hygro
85mm Micro lens
IR Thermo
Delmhorst
Micrometer
DSLR
Field Microscope
Numbers
Photocard & scale
Swabs, Syringes…
Analytical Tests
International Roof Coatings Conference Coatings Forensics for Roofing
“Finger Print” methods Low Temperature Ashing (ASTM D3723)
Water Absorption (ASTM D471/D570)
XRF (X-Ray Fluorescence Spectroscopy
FT-IR (Infrared Spectroscopy)
Photomicroscopy Digital Image Processing
Finger Prints
International Roof Coatings Conference Coatings Forensics for Roofing
Low Temperature Ashing (ASTM D3723) Ash is a simple method, but has very high precision
Requires a kiln, a desiccator and an analytical balance or
Automated Ash test (AZI Computrac Max 5000)
It is useful not only in forensics but also production/QC
Provides some qualitative information…
65.8% Pigment
- organic pigments
- waters of hydration
Finger Prints
International Roof Coatings Conference Coatings Forensics for Roofing
Water Absorption (ASTM D471/D570) Provides important qualitative information
Detects Production Defects
Can be used for chemical resistance/Crosslinking
0 1 7 14 28
Finger Prints
International Roof Coatings Conference Coatings Forensics for Roofing
XRF (X-Ray Fluorescence Spectroscopy) Identifies fillers, pigments & colorants & their sub-ingredients
High sensitivity but penetrates multiple coating layers
Allows factoring out of filler effects with IR
Can be used to identify contaminants
FT-IR (Infrared Spectroscopy) Limited usefulness within similar polymers
Can be quantitative
Can be combined will data mining tools
Well known, authoritative
Can do “archeology” with IR
Third party labs have IR records
Photomicroscopy
International Roof Coatings Conference Coatings Forensics for Roofing
Copy Stand and Macro set-up Use DSLR with professional macro lens
Need extension tubes and macro-stage
High ISO rating >3200 camera
Fiber Optic illumination
Can do UV and NIR photography
Photomicroscopy
International Roof Coatings Conference Coatings Forensics for Roofing
Standard Stereo Microscope w. DSLR Small DSLR/P&S with adapter tube
Used manually, but has video link
High ISO rating 3200-6400 camera
Fiber Optic illumination
Can do UV and NIR photography
Higher power CMO microscope available
Prefer trinoccular format
OEM camera also have software tools
Trapped moisture
under polyurethane
(40X)
Digital Processing
International Roof Coatings Conference Coatings Forensics for Roofing
Photoshop CS6
Color balance, lens correction…
Panoramic stitching
HDR (high dynamic range)
Helicon Focus Focus Stacking (EDF)
Ultimate solution is Keyence VHX-1000
Photomicroscopy
International Roof Coatings Conference Coatings Forensics for Roofing
NIR Photo, to prove color match
Camera: Nikon D-90
IR Filter: Hoya Infrared R72
Processing: Photoshop CS5
Composite Photo: 8 images
Camera: Nikon D-90
Copy Stand and Velbond Macro stage
Processing: Helicon Focus & Photoshop CS5
Photomicroscopy
International Roof Coatings Conference Coatings Forensics for Roofing
Macro Photo ~4X
Underside, looking up, of blister
Camera: Nikon D-90
Processing: Photoshop CS5
Macro Photo ~4X
Looking down into 45 degree cut
This is a chalking complaint
with a very thin layer of brown over white acrylic
Camera: Nikon D-90
Processing: Photoshop CS5
Photomicroscopy
International Roof Coatings Conference Coatings Forensics for Roofing
Macro Photo 1X, F-32
Asphalt Bleed Through
Camera: Nikon D-90
Resources
International Roof Coatings Conference Coatings Forensics for Roofing
Juran, J. M. (1979). Juran’s Quality Control Handbook. (3rd ed., pp. pg.
16-32). New York, New York: McGraw Hill.
Jones, P. (2011) Practical Forensic Digital Imaging: Baton Rouge, FL
Weldon, D.G. (2009) Failure Analysis of Paints and Coatings: West
Sussex, UK
Golton, W.C. (1992) ASTM STP1110 Analysis of Paint and Related
Materials: Current Techniques for Solving Coatings Problems.
Philadelphia, PA
Hamburg H.R. (1979) Hess Hess's Paint Film Defects, Their Causes and
Cure, (3rd Edition)
Koleske, J.V. (2012), Paint and Coating Testing Manual, 15th Edition of
the Gardner-Sward Handbook - ASTM MNL17-2ND: Philadelphia, PA