A-A: An APA panel rating that refers to a sanded plywood panel with A-grade face and back plies, D grade inner plies and bonded with interior glue.

A-A Exterior grade: An APA panel rating that refers to an exterior grade sanded plywood panel with A-grade pace and back plies and C-grade inner plies. Bonded with exterior glue and commonly used for fences, built ins, signs, boats, cabinets, commercial refrigerators, shipp

A-B: An APA panel rating that refers to a sanded plywood panel with an A-grade face, B-grade back and D- grade inner plies. Can be bonded with interior or exterior glue. Commonly used as a substitute for A-A when the appearance of one side is less important.

A-B Exterior: An APA panel rating that refers to an exterior grade sanded plywood panel with A-grade face, B-grade back, and C-grade inner plies. Bonded with exterior glue. Commonly used as a substitute for A-A exterior where the appearance of one face is less importan

A-C exterior: An APA panel rating that refers to an exterior grade of sanded plywood panel with A-grade face, C-grade back, and C-grade inner plies. Bonded with exterior glue. Commonly used for soffits, boxcar and truck linings, and other high moisture applications whe

A-D: An APA panel rating that refers to a sanded plywood panel with A-grade face, D-grade back and D-grade inner plies. Bonded with interior or exterior glue. Commonly used for paneling, built-ins, shelving, partitions where only one side is important.

abrasion: The process of wearing down of a surface due to rubbing by course objects that cause small portions of the surface to be removed.

abrasion resistance: The property of a surface that resists being worn away by a rubbing or friction process. Abrasion resistance isn’t necessarily related to hardness, as believed by some, but is more closely comparable to, or can be correlated with the toughness ability of

abrasive: A substance that is very rough and which is used to wear down a surface. Sandpaper is an abrasive.

absorption: The process by which wood takes in water or other liquids such as finishing agents.

accelerator: Any substance that speeds up the curing time of an adhesive or the drying time of a finishing agent.

accent strip: A strip of wood flooring used in contrasting color to the rest of the flooring. Often used around the edges of a room or other areas.

acclimation: The act of allowing wood moisture content to become at equilibrium with the environment in which it will perform. Also see EMC.

acetone: The simplest ketone, a highly flammable organic compound, widely used as a solvent.

across the grain: The direction at right angles to the length of the longitudinal elements of wood.

acrylic: This refers to both a finishing agent and a chemical compound that is used in some other finishes.

acrylic lacquers: A high quality clear system for finishing cabinets, furniture and a wide variety of wood and novelty items. They are water white in color with excellent non-yellowing qualities. Available in both solvent type and water reducible products.

activator: The curing agent of a two component/compound adhesive system such as a two part epoxy.

actual size: The true exact measured width or length of a piece of lumber.

add-on: The dimension that represents the difference between the cabinet opening and the finish door size. Typically ½ to 1” added to the width and length of the cabinet opening, resulting in the door finish size.

additives: Chemicals added to paint/primer to affect performance, prevent mold/mildew or block tannin bleed and stain.

adhesion: The property causing one material to stick to another, the strength with which an adhesive acts. The degree of attachment between a finish step and the underlining material .

adhesive: A substance that is capable of bonding two materials together by surface attachment. Types include cement, mucilage, paste, and glues.

adhesive joint: A joint that uses adhesive instead of nails or screws. A location at which two objects are held together with a layer of adhesive Term synonymous with glue-joint.

adsorption: The adhesion of molecules of a liquid or gas to the surface or a solid. This is a weak bond and is generally much weaker and less permanent than absorption.

adult wood: A term synonymous with mature wood.

advanced decay: The latter stage of decay in which destruction is readily recognized by soft, pitted, or crumbly areas, frequently accompanied by obvious discoloration of the wood.

AFA: The abbreviation for the American Forestry Association

air bubble: A dry bubble in coating film caused by entrapped air. Often caused by applying the finish coat too heavily or due to excessive brushing.

air drying: A finishing material is said to be air drying when it is capable of hardening or curing at ordinary room temperature i.e., 60 to 80 degrees F.

air entrapment: Inclusion of air bubbles in coating film.

air – dried: Dried by exposure to air in a yard or shed without artificial heat. Not kiln dried.

airborne contaminants: Foreign substances introduced into the air which can cause film defects.

alcohol: A group of solvents of relatively high evaporation rate but with relatively low solvent strength. Commonly used as a solvent in shellac, some stains, dyes, inks and lacquer.

alkyd: A type of synthetic resin used as the vehicle or modifier in coating, usually to increase such things as hardness, toughness, and flexibility.

all heart: Refers to lumber that is pure heartwood, no sapwood.

alligatoring: The appearance of a paint, varnish or lacquer film that is cracked into large segments, resembling the hide of an alligator. Caused by heavy coats, by recoating before the bottom coat is completely dry, by the use of thinners that evaporate too quickly, o

amber: An orange color found in some resins and varnishes; a yellowish translucent resin formerly used in the manufacture of varnish.

ambient moisture content: The moisture content of wood when it has come to equilibrium with the ambient humidity and temperature. Also called equilibrium moisture content.

ambrosia: The name of a beetle which attacks some woods, particularly maple. The beetles share a symbiotic relationship with the ambrosia fungus. This fungus causes a discoloration found radiating up and down the grain from the holes that the beetle creates as it b

ammonia: A pungent gas compounded of nitrogen and hydrogen that is used in woodworking in the process of fuming wood.

aniline (acid) dye: Synthetic colors which dissolve in the solvent for which they are formulated. I.e. - water, alcohol, or oil. Aniline dye stains must be specified, and are always applied to the raw wood before sealing in any system.

annual growth rings: The layer of wood growth, including spring and summer wood formed on a tree during a single growing season.

Appalachian: Lumber logged from the region along both sides of the Appalachian range, running thru western Tennessee, Kentucky, West Virginia, Virginia, Maryland, Pennsylvania, and New York.

appearance grade: A grade for wood or composite material (Plywood) that is concerned only with the surface appearance and make no direct statement about structural characteristics. Clear is an appearance grade for lumber.

application: The process by which a finishing agent is put on a surface. Techniques include: brush, dip, pad, pour, roll, spray, wipe.

applicator: A device with which the application of a finishing agent to a surface is accomplished. Ex: brushes, cloth, spray guns, etc.

applied carving: A wood carving worked separately and then applied (glued on) rather than being worked in place.

apron: A rail from one leg to another of a table or chair. The bottom piece of a sill. Wood flooring outside the border Also called frame of skirting.

arbor: A rotating shaft driven by a motor and serving as an axis for larger rotating parts such as a blade on a saw or the cutting head on a shaper. A structure designed to be covered in plants to provide shade.

arris: The sharp edge where two surfaces meet at an angle- the corner where the face and an edge of a plank meet.

aspect ratio: The ratio of width to height. It is relevant to woodworking in that the creation of rectangles with identical aspect ratios, albeit different sizes is the goal particularly in artistic creations.

asphalt saturated felt paper A#15: A commonly used as a vapor retarder.

atomization: formation of tiny droplets of liquid in a spraying process. A finish that is properly atomized will produce tiny droplets of mist that will easily coat a surface uniformly. A poorly atomized coating will consist of larger droplets that may not flow out to