quality control of Surface preparation

3.27 Hydro-Blasting See water blasting.

3.28 Inhibitor
General term for compounds or materials that slow down or stop an undesired chemical change
such as corrosion, oxidation or polymerization, drying, skinning, mildew growth, etc.

3.29 Laitance
A milky white deposite on new concrete.

3.30 Manual Cleaning
Includes hand cleaning and power tool cleaning.

3.31 Masonry
Construction composed by shaped or molded units, usually small enough to be handled by one
man and composed of stone, ceramic, brick or tile, concrete, glass, or the like.

3.32 Masonry Cement
A hydraulic cement for use in mortars for masonry construction, containing a type of cement plus one or more material such as hydrated lime, limestone chalk, talc, slag or clay.

3.33 Maximum Amplitude
The term “maximum amplitude” as used in this Standard is defined as the greatest vertical
distance between the summit of any peak on the blast-cleaned surface and the bottom of an
immediately adjacent trough, but without taking into account any exceptionally high “rogue peaks”

which are liable to occur on a blast-cleaned surface as a result of embedded particles of
abrasive. Such peaks are very undesirable and their size and number may be the subject of special agreement between the parties to a contract. quality control of surface preparation

3.34 Metal Spraying
Application of a spray coat of metal (usually zinc or aluminum) onto a prepared surface. The metal
to be sprayed is rendered molten by passing it, in wire or powder form, through a flame pistol that
projects the semi molten metal onto the surface by means of a jet of compressed air.

3.35 Mill Scale
Mill scale is the term used for the surface oxides produced during hot rolling of steel. It breaks and
flakes when the steel is flexed and paint applied over it may fail prematurely. The extent of such
failures is unpredictable but they frequently occur within a few weeks of painting, particularly in
aggressive environments.

No protective coating can give long-life protection unless both the scale and rust are
removed.

3.36 Passivation
Act of making inert or unreactive.

3.37 Phosphating
Pretreatment of steel and certain other metal surfaces by chemical solutions containing metal
phosphates and phosphoric acid as the main ingredients, to form a thin, inert, adherent,
corrosion-inhibiting phosphate layer which servies as a good base for subsequent paint coats