Surface Prep Flashcards
Proper surface preparation is necessary for
Adequate bonding of coating
full protection of substrate
avoiding early paint failure
which of the following presents the least coating problem
surface texture
what is a consideration in determining the best method of surface preparation
-generic type of coating
-type of substrate
-type of environment presetn
which of the following will cause loss of adhesion on a surface to be coated
-loosepaint chalk
-rust
-oil
pinpoint rusting of recently coated steel is frequently related to
too high a surface profile
which of the following surface preparation systems pose a health or safety hazard
-abrasive blasting
-flame cleaning
-solvent cleaning
oil and grease are best removed from steel by
solvent washing or steam cleaning
hand tool cleaning effectively removes from steel
loose paint or rust
inhibitors are used in wet or water blasting of steel to
prevent flashing rusting
abrasive blasting
is best when a high level of surface preparation is required
what are the best methods for removing contaminants
hand power tool-loose mill scale, rust and paint
solvent cleaning-oil and grease
water blasting-marine growth and loose chalk
abrasive cleaning-all rust and mill scale
what method of solvent cleaning is more effective than the rag or brush scrubbing method
immersion method
when is it most advantageous to use steel grit or shot for abrasive cleaning
when cleaning ferrous metals
What additive is blended with teh wet sand to prevent rusting while wet blasting
rust inhibitors
what are the main advantages of wet blasting
reduces the dust
in order to prevent discoloration of latex paint on a masonry surface, what preparation must be accomplished before painting
all alkalinity must be neutalized
what procedure is used for removing grease oil soil and other contaminants from steel surfaces manually
solvent cleaning
what type of blasting system is used for removal of paint marking from concrete paving
the portable abrasive blaster
what is the minimum allowable flash point for solvent used for surface cleaning
100 degrees F
what problems are created for the painter when steel is coated with zinc metal and chemical treatment that prevents corrosion
adhesion of coatings after exposure
what is white rust? when is it encountered
white deposit on zinc when in humid area
what blast cleaning method is considered to provide a high degree of cleaning for paoint systems under normal exposure conditions
commercial blast
which method of abrasive cleaning is used for cleaning loose paint from masonry
commercial
what type of mateial is most often cleaned by the blat method
metal
when the maximum performance is required from a pain system, what type of blast system is called for
white metal blast
which of the following powdered abrasives is best for all around use
pumice stone
a major advantage of the use of power tools is
the reduced time in preparation substrate required
what balst cleaning method should be sued to prepare the surface for coatings that are exposed to corrosive atmospheres
white metal blast
when a power wire wheel is used for cleaning metal surfaces, why must polishing the surface be avoided
reduces the adhesive property for future coat
a scaling hammer must not be used on plate heavier than one-fourth inch (t/f)
false
what additional cleaning is required following a flame type cleaning of a painted surface
wire brushing
when would a blast cleaning operation call for the use of sand as the abrasive particle
when grit is unavailable
what is the dominant factor to be considered when selecting a grit for a particular blast cleaning job
the surface contamination to be removed
what preparation should be made for painting corrosion resistant metals
minimum surface roughening
what is one of the requirements when wet blasting is used
special hoses are necessary
what degree of abrasive blast cleaning is the most time consuming
white metal
when is the vacuum blast method most efficint and economical
when it is semi-open
what type of blasting requires the surface to be vacuumed to remove grit residue
dry conventional blasting
the terms vacuum blasting and dry honing are synonymous (T/F)
True
what is another name for dry honing
vacuum blasting
why do all blasted metal surfaces require prime painting be started and completed the same day
to prevent rust from forming upon the surface
the reason extra care is taken in painting metal is
-to prevent rust
-to be sure paint adheres
iron is primed with blue lead, or zinc chromate properties in the primer to prevent rust (t/f)
true
Excess moisture will cause
blistering and peeling
what is the most important thing when doing a paint patch
surface preparation
to finish paint grade wood, the first step is to
fill holes
the most important thing to do before repainting is to
prepare the surface
