test questions to study for 14-17-18 Flashcards
Dry film thickness matches up with
Applications
it is ______ to know surface conditions before preparation
important
how well just primer on the the steel be protected
it provides a corrosion free surface for the steel
SCAT stands for
surface contamination analysis test
it is t/f that baking soda is used as blasting material
true
t/f is coating specification a legal and enforceable document
true
t/f lead paint is dangerous
true
how does humidity effect life of coating
it shortens it. should not coat when relative humidity
below 5F or 3C
pinpoint corrosion is caused by
overspray
what does a contractor get out of the specifications
a clear understanding of the requirements of the specification
is writing a specification easy
no
is a good specification a guarantee against coating failure
no
is a specification for new construct same as for repair work
no there are more variables
does an application contractor help with developing specification
no
does a specification usually stipulate just one coating system
no 2 or more approved systems
should coating inspector attend pre-job meeting
yes
did osha and epa develop standards for coating specs
no
who determines method for preparing the surface coating
the specifier
what kind of failures are chalking, checking, and cracking
formulation- related failures
does substrate have effect on coating performance
yes
examples of surface preparation
white metal blast cleaning near white metal blast cleaning commercial blast cleaning acid pickling brush off blast cleaning solvent cleaning
application failures
poor workmanship runs,sags, curtains brush marks improper coating thickness overspray pinholes holidays spatter coat
where stripe coating is used
nuts bolts welds corners edges
construction aids
what causes rapid coating failure
exterior forces : chemical exposure abrasion reverse impact severe weathering
formulation failure can cause
chalking
checking
cracking
discoloration
checking failure
on surface only
what causes alligatoring
when a hard, tough coating is applied over a soft coating.
top coat shrinks and floats and bottom coat doesn’t .
mud cracking
similar to alligatoring but reaches the substrate
what kind of coating prone to Biological attack
Organic (polyamide coating)
How many ways microorganisms affect the coating
Bacteria (use coating for food and derive energy from them)
Fungi (highly humid atomsphere; northern hemisphere on the north sides of tank and building surfaces)
what kind of rusting does overspray cause
pinpoint rusting
which surfaces are easier to coat new or old
new is easier
will other coatings work well over galvanized surface
no they will fail rapidly
does substrate have effect on coating performance
yes
sulfate contamination can cause ________ to substrate
pinpoint rusting
remaining pits after blasting
rust
chlorides
sulfides
blushing
haze deposit on surface. was exposed to moisture while curing
