ANSWERS FIRM A+
✔✔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 (0.8 - 2.5 mils)
-X-Coarse (1.5 - 4.5mils)
✔✔List the Standards for using Replica tape: - ✔✔ASTM D 4417 Method C
NACE SP 0287-2002
✔✔When using Replica tape common errors include: - ✔✔variation in point-to-point
profile 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
✔✔Good records allow management to: - ✔✔1. Detect design defects 2. Evacuate
coating performance 3. Develop ongoing maintenance program 4. Determine annual
cost data
✔✔One guide for enclosures for coatings projects is: - ✔✔SSPC Technology Guide No.
12, SSPC Technology Update No. 6 Guide for Containing Surface Preparation Debris
Generated During Paint Removal Operations
✔✔Low temperature concerns during coating application include: - ✔✔-Slow the curing
of chemically curing coatings
-Will increase the viscosity of material
-Some coatings may use special cure
✔✔High Temperatures concerns during coatings application include: - ✔✔Solvent
evaporating too fast
Will reduce pot life
Decrease the viscosity of many two-component materials
✔✔High humidity during coating application: - ✔✔Slows the evaporation of the solvent,
can leave moisture on the surface of the coating, may effect the gloss or color, may
cause amine blush (must be removed prior to top coating)
✔✔Some of the problems that can be caused by amine blush are: - ✔✔surface
tackiness or greasiness, incomplete curing, poor adhesion, coating discoloration, poor
gloss retention
, ✔✔Runs, sags and wrinkles are caused by: - ✔✔1. Coating applied too thickly 2. Too
much thinner 3. Surface too hot 4. Improper spray technique
✔✔What percentage of NACE Standards relate to coatings? - ✔✔50%
✔✔Chalking - ✔✔Powdery deposit being formed on a dry paint film surface. Most
common with Epoxy coatings.
✔✔Cratering may be caused by: - ✔✔Air trapped in coating
✔✔A common cause of blistering is: - ✔✔Surface Contamination under the applied
coating
✔✔Vacules or voids are typically caused by: - ✔✔running the mixer too fast
✔✔Pinholes are: - ✔✔Very small holes in a coating typically caused by air or solvent
trapped in porous film and escaping.
✔✔Cracking of a coat is noted: - ✔✔When the crack extends to the substrate
✔✔Checking can be Described as: - ✔✔fine cracks in the surface of a coating that don't
extend through to the substrate
✔✔Adhesion Failures May be Caused by: - ✔✔1. Contaminated surface 2. Wrong
surface prep. 3. Insufficient profile 4. Exceeding topcoat window
✔✔General types of holiday detectors include: - ✔✔Low-voltage DC, High-voltage DC,
High-voltage AC
✔✔Low-voltage (wet sponge) holiday detectors are powered by batteries with output
voltages ranging from ______. - ✔✔5 - 120 V DC
✔✔What is a Standard? - ✔✔An established norm or requirement that is written by
industry professionals.
A formal document that establishes uniform engineering or technical criteria, methods,
processes and practices
✔✔Describe low voltage holiday detectors - ✔✔-Ground cable attached directly to
substrate
-Sponge saturated with a solution of tap water
-maximum rate of (1 linear ft/sec) double stroke
-used on coatings up to (20 mils)