Week 2 Quiz Flashcards
The two broad classification for curing mechanisms are
convertible and non-convertible
the two non-convertible coating types are
chlorinated rubber and vinyl
the primary convertible coating curing mechanisms are
Oxidation, Co-reaction (polymerization), Hydration, and Fusion
The characteristics of oxidation cure coatings are
Not suitable for immersion service.
Not suitable for use over alkaline substrates.
Limited dry film thickness per coat.
List the coating types that cure by polymerization
Epoxies Polyurethanes Polyureas Polyaspartics Polysiloxanies
Induction time is
The time required by the product data sheet (coatings manufacturer) between mixing the coating and the start of application.
What is the main requirement for a hydrolysis coating to cure?
Moisture
Industrial and marine coatings are commonly referred to by
Generic resin type
Oil based coatings applied over alkaline surfaces may result in
Saponification
List the formal sections usually contained in a good specification
Scope of work Terms and Conditions Reference standards and codes Safety Pre-job conference Surface preparation Coating Materials (includes the coating schedule) Sampling Coatings Workmanship Application Work Schedule (sequence of work to be done) Repairs and remedial coating work Inspection Documentation
What are two of the inspector’s responsibilities as it relates to the specification?
Verify the specification and not to make changes to the specification.
During the surface preparation, surface cleanliness should be inspected (as minimum) the following three times:
Before any surface preparation activities.
After surface preparation, before coating begins.
Between each application of coating in a multi-coat system.
Factors during surface preparation that may effect service life include:
Residues of oil, grease, and soil Residues of (non-visible) chemical salts Rust on the surface Loose or broken mill scale Rust scale Anchor pattern Defects mechanical cleaning equipment Surface condensation Old coatings that may have poor adhesion or may be too deteriorated for recoating Existing coatings that may be incompatible
Common design defects include
Hard-to-reach or inaccessible areas
Rivets, bolts, or other connectors
Welds
Gaps (particularly skip welds or surfaces close together)
Overlapping surfaces (e.g., roof plates in water tanks)
Angle iron badly oriented or in complex arrangements
Threaded areas
Dissimilar metals
Sharp edges, particularly on corners or rough cut plate
Construction aids
Common fabrication defects include
Weld Spatter
Skip Welds
Rough Welds
Sharp Corners & Edges
SSPC SP1 pre-cleaning methods include:
Solvent wipe with cloth or rag Immersion or the substrate in solvent Solvent spray Vapor degreasing Steam cleaning Emulsion cleaning Chemical Paint Stripping Use of alkaline cleaners
The standards for Power Tool Cleaning
SSPC-SP3
SSPC-SP 15
SSPC-SP11
ISO 8501-1, St2 or St3
Tools used for Power Tool Cleaning are
Rotary Wire Brushes Impact tools Needle Scaler Rotary Scalers Piston Scalers Grinders and sanders Disc Sanders
Abrasive Blasting methods include
Centrifugal blasting Sand-injected water blast Slurry blast Wet abrasive blast Dry grit Blast Cleaning (Air Blasting)
Visual Standards for abrasive blasting include
SSPC-Vis 1
ISO 8501-1
SSPC SP 10/NACE 2 limits staining to
5% per each unit area
SSPC SP 5/NACE 1 limits staining to
0% per each unit area
SSPC SP 6/NACE 3 limits staying to
33% per each unit area
The two types of abrasive blasting nozzles include:
Straight
Venturi
The specified level of surface cleanliness must be achieved and maintained
immediately prior to coatings application
Advantages of centrifugal blast equipment include:
Dust and Fines are contained
Abrasives are easily recycled
Blasting and priming can be an inline operation
General overall economy compared to air blasting
No compressors, piping, or air handling equipment needed for wheel blasting
The Inspectors checklist for surface preparation should include:
Ambient conditions Conditions of substrate Pre-Blast surface cleanliness Shot/Grit size selection Shot/Grit Cleanliness Abrasive Blasting Equipment Surface Profile Surface Cleanliness after abrasive blasting Operator qualifications Safety
Abrasive media types include:
Shot & Grit (metallic) Crushed Slag Ceramic Grit Silica Sand Garnet Agricultural Abrasives Specialty Abrasives
Abrasive media typically used for recycling include:
Steel Shot
Steel Grit
List the pressure ranges that categorize:
Low Pressure Water Cleaning: <34 MPa (5,000 psi)
High-Pressure Water Cleaning: 34 to 70 MPa (5,000 to 10,000 psi)
High-Pressure Water Jetting: 70 to 210 MPa (10,000 to 30,000 psi)
Ultrahigh=Pressure Water Jetting: >210 MPa (30,000 psi)
Three types of Water-Blasting include:
Grit blasting with a shroud
Sand injected Water Blast
Slurry Blast with Grit/Water Mix
The NACE/SSPC Waterjetting Standard is
SSPC/VIS 4 and VIS 7 are visual comparators to be used with the standard
Three Test Methods for surface profile include:
Comparator and coupons
Replica tape
Digital Surface Profile Gauge
Types of Soluble Salt Contamination include:
Chlorides
Sulfates
Nitrates
If inspection is to be effective with regards to soluble salts, the specification should very clearly state:
Limits to be accepted Specific salts to be limited Test method to be used Frequency of testing Locations in which tests should be administered
Test for soluble salts include
Bresle Patch
Sleeve Test
Soluble Salt Meters
Conductivity Meters
Depth of surface profile can be evaluated by several methods
ISO comparator
Replica Tape
Digital Profile Gauge
The ISO Comparator grades may be recorded
Finer-than-Fine Grade Fine Grade Medium Grade Coarse Grade Coarser-than-Coarse Grade
The two types of replica tape are commonly used:
Coarse - for 20 to 64 um (0.8 to 2.5 mils)
X-Coarse - for 38 to 115 um (1.5 to 4.5 mils)
List the standards for using the Replica tape
ASTM D 4417 Method C
NACE SP 0287-2002
When using Replica tape common errors include:
Variation in the point-to-point over the surface being tested
The presence of particles of dirt on either the replica tape or gauge
Gauge Accuracy
The rubbing or burnishing technique
