GLOSSARY 

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O 

OIL-BASED COATING (PAINT)

A paint or varnish that contains resins or oil varnish and drying oils as the basic film-forming ingredients and is converted to a solid film primarily by chemical reaction (usually oxidation). 

OIL LENGTH

The ratio of oil to resin in a medium. For an oleo-resinous varnish, the oil length may be expressed in terms of parts by weight of oil to one part by weight of resin.

OIL STAIN

A solution of dye in a blend of oil or varnish and solvents. Some oil stains are pigmented in order to reduce the depth of penetration of the stain. 

OIL VARNISH

A varnish that contains resin and drying oil as the basic film-forming ingredients and is converted to a solid film primarily by chemical reaction. 

OLEORESIN

A natural plant product that contains oil and resins. Turpentine is an example. 

OLEORESINOUS VEHICLE

A vehicle prepared by the addition of a resin to a drying oil. 

OPACITY

The property of a paint that enables it to hide and colour a surface. 

OPEN ABRASIVE BLAST CLEANING

An air abrasive blast cleaning operation without any localized containment surrounding the blast stream. 

OPEN GRAIN WOOD

Wood that has loose, open formation with minute openings between the fibers. Examples: oak or walnut. 

OPEN TIME

The length of time a wallcovering adhesive is tacky and bondable.  

ORANGE PEEL

The dimpled appearance of a dried coating film resembling the skin of an orange. 

ORBITAL SANDER

A power sander with a flat abrasive pad that is vibrated in small, circular motions. 

ORGANIC ZINC-RICH COATING

Anti-corrosive primer for iron and steel incorporating zinc dust pigment in an organic vehicle. The most common types of binders for organic zinc-rich coatings are epoxy polyamide, urethane, vinyl, and chlorinated rubber. 

ORIFICE

Opening or hole in a spray or blast nozzle. 

OUTRIGGER BEAM

A fixed or movable arm that extends beyond the edge of a roof or structure. It is used for rigging scaffolds.

OVERLAP SEAM

See WALLCOVERING SEAM. 

OVERSPRAY

Spray particles that are not wet enough to fuse when they reach the surface being sprayed. 

OXIDATION

Corrosion of metals and degradation of other substances caused by oxygen in the air.