Coating Types, Failure Modes, & Inspection Criteria Flashcards
What are the types of curing mechanisms?
- Convertible (chemical change during cure cycle)
- Non-Convertible (no chemical change during cure cycle)
What is a convertible curing mechanism?
Chemical change during cure cycle
What is a non-convertible curing mechanism?
No chemical change during cure cycle
What are some examples of non-convertible coatings
- Chlorinated rubber
- Vinyl coatings
- Acrylic coatings
- Bituminous coatings
What are common failure modes for chlorinated rubber?
- Blistering
- Pinholes
Name critical inspection criteria for chlorinated rubber.
- Thickness tolerance
- Substrate temperature
What are common failure mode(s) for vinyl coatings (non-convertible)?
- Blistering
Name critical inspection criteria for vinyl coatings (non-convertible).
- Thickness tolerance: minimal
- Substrate temperature
- Ventilation: adequate
What are common failure mode(s) for bituminous coatings?
- Cracking
- Delamination
Name critical inspection criteria for bituminous coatings.
- Thickness tolerance
- Application technique
What are common failure mode(s) for epoxy coatings (two component)?
- Failure to cure
- Pinholes
- Sagging
- Delamination
- Chalking
- Blushing
What are common failure mode(s) for zinc rich epoxy?
- Failure to cure
- Pinholes
- Sagging
- Delamination
- Chalking
- Blushing
same as regular epoxy coatings
Name critical inspection criteria for epoxy coatings (two component)
- Mixing
- Thinning
- Thickness tolerance
- Enivronmental conditions
Name critical inspection criteria for zinc rich epoxy
- Mixing
- Thinning
- Enivronmental conditions
What are common failure mode(s) for polyester and vinyl ester coatings?
- Failure to cure
- Blistering
- Delamination
Name critical inspection criteria for polyester and vinyl ester coatings
- Environmental conditions
- Application equipment and process
What are common failure mode(s) for polyurethanes (thin film)?
- Cracking
- Loss of gloss
- Uneven color appearance
Name critical inspection criteria for polyurethanes (thin film)
- Mixing
- Environmental conditions
- Thickness tolerance
What are common failure mode(s) for polyurethanes (thick film & hybrids)?
- Failure to cure
- Delamination (won’t coat itself)
Name critical inspection criteria for polyurethanes (thick film & hybrids)
- Mixing
- Environmental conditions
- Thickness tolerance
What are common failure mode(s) for siloxanes?
- Cracking
- Delamination
- Improper curing
Name critical inspection criteria for siloxanes
- Mixing
- Environmental conditions
- Thickness tolerances
What are common failure mode(s) for silicones?
- Peeling
- Flaking
- Delamination
Name critical inspection criteria for silicones
- Heating schedule
- Thickness tolerance
What are common failure mode(s) for inorganic zincs?
- Mud cracking
- Failure to cure
Name critical inspection criteria for inorganic zincs
- Environmental conditions
- Thickness tolerance
- Mixing
- Application process
A coating film that involves a chemical change within the resin/binder during curing is called a _______.
A. Non-convertible coating
B. Vinyl
C. Chlorinated rubber
D. Convertible coating
D. Convertible coating
Which resin type is commonly blended with other resin types because of its excellent resistance to UV degradation?
A. Epoxy
B. Aromatic polyurethane
C. Alkyd
D. Acrylic
D. Acrylic
Coatings that cure by a chemical reaction yet are packaged in a single container are?
A. Alkyds/oil enamels
B. Amine epoxy
C. Moisture cured urethane
D. Polyurea
A. Alkyds/oil enamels
C. Moisture cured urethane
Which of the listed coatings failures is common to both convertible and nonconvertible coatings?
A. Incorrect film thickness
B. Failure to add the ‘B’ component
C. Improper formulation
D. Wicking due to glass fiber in film
A. Incorrect film thickness
Pure silicone coatings typically require a two-step cure process where the first step is solvent evaporation. What is the second step?
A. Oxidation curing
B. Heat (fusion) curing
C. Hydrolysis
D. Co-reaction curing
B. Heat (fusion) curing
heat cycle
