Fritz Kohl Furnierwerk

Glossary

Know-how about wood and veneer – from A - Z

A | B | C | D | E | F | G | H | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | Y |

A

Air Drying

Earlier the most usual method of drying veneers. These were placed as single or double leaves in so-called stacking carriages and were dried completely without any technical aids or fan. Very time-consuming. Natural drying has been replaced by jet drying.

Air-Dried Lumber

Solid wood which has been air dried without kiln drying.

Archtectural Grade

Top quality log and veneer length over 2.65 m.

B

Backing

The lowest grade veneer which is generally only used yet as cross- band veneers or for non-visible surfaces. Sold generally by the ton.

Backing Board

The boards which remain after slicing wood. Much appreciated as so- lid wood because these generally include the standing years and thus are relatively free of tension.

Birdseye

The term given to eye-shaped marking of the veneer, especially in the case of Birdseye Maple.

Block Mottle Figure

An irregular form of figuring which runs over the complete surface of the veneer.

Blue Stain

Blue stains on the surface of the veneer which occur through insuffi- cient water extraction when slicing (too low heating capacity on the pressure bar or when slicing too fast) because water remaining on the surface of the veneer turns blue through oxidation.

Book

The most commonly used term for a bundle of veneer, especially
by carpenters. This term comes from the veneer leaves following one after the other like pages in a book.

Book Match

A procedure in the further processing of veneers by which the succes- sive veneer leaves are glued alternately with the front and rear side to retain a mirror-inverted sequence.

Buckle

Corrugation caused in the veneer leaf when drying as a result of dif- ferent drying runs and irregular annual ring development within the veneer leaf. The veneer has to be flattened again to make the veneer saleable.

Bundle

Cut bundles of veneer generally containing 24 or 32 consecutive leaves in cutting sequence.

Burl

A term for veneers which are produced from the burr or burl formation. Differentiation is generally made between burl or burr growth above ground (Elm, Ash, Oak) and root burl or burr growth which develops below ground in the root (Californian Walnut, Madrone, Vavona, Myrtle).

Burl-Log

Term used for a burly trunk, log or veneer cut.

Butt

The bottom end of a log or veneer frequently featuring coarse annual ring development and undesired color variations caused by its root- stock.

C

Cancer

A disease of the European Oak which destroys the structure in the veneer and appears as open defect in advance stadium. Very difficult to recognize in the bark.

Cathedral Structure

Much sought after structure in crown cut bundles. Considered to be very elegant.

Chatter Marks

Deviation in veneer thickness caused through vibration of the veneer block on the slicing machine or by wrong pressure setting on the machine, showing on the veneer leaf as regularly distributed cross running strips. The veneer block vibrates when the log is not firmly clamped flat on the cutting table.

Clipping

The clipping of veneers on the veneer cutter whether the veneers are in their initial or in final production.

Cluster

Only partially burled logs.

Complete Flitch

Veneers which are not only produced from one log but where all leaves remain in their exact original log sequence.

Compression Wood

The zones given in soft wood through irregular annual ring structure which are particularly hard and, therefore, cause difficulties when slicing the veneer.

Condensate

The tannic acid which is yellow in color and deposits on the surface of the veneer when it is dried too sharply.

Cross Grain

Buckling of the veneers given through irregular growth or through logs under high tension. It shows itself also as darker coloring down the annual rings.

Crotch

Crotch veneer figuring sometimes termed “curl” which is manufac- tured from the intersection of the limb or branch with the main trunk (see page 273). The quality is all the better the more precise and distinct the curl or crotch and feather are.

Crown Cut

The first bundles from a log when sliced over the heart. Produces the so-called cathedral structure.

Curl

»Crotch

Curly Fishbone Figure

Typical figure development especially in beech which is generally
considered to be degrading.

D

Defect

Overgrown branch which leaves a clearly distinct bark pattern. The earlier the tree has got rid of its branch the less visible is this characteristic in the bark.

Din

The standards valid in Germany for the production of veneer. The standard thicknesses are laid down therein.

Discoloration

Undesirable color variations in the veneer, e.g. green stripes in European Cherry.

Divider

A strip of wood placed between the veneers to increase the strength of a pallet or to ensure the stability of the flitches stacked in log-form. Also separates the different logs from each other.

Door Length

Log and veneer lengths between 2.05 m and 2.40 m required by the door industry.

Drier Prints

Black patches are given on the surface of the veneer caused by defec- tive, uncleaned or unserviced drier belts. These black patches cause problems when sanding and treating the surface of veneers.

E

Egg Shape

A structure in the crown cut bundle desired by the piano industry. Required by them for the fronts and lids of their instruments.

F

Fiddle, Fiddleback, Figure

Clearly visible and more or less regular streaks running across the grain in different species of wood (e.g. in Sycamore, Macore, Peartree, Ash). The more regular these streaks are the more valuable
the veneer.

Fingered Heart

Irregularly developed heart.

Flake

The typical figuring of wood when the pithrays are cut across, i.e. at an angle of 180 degrees when slicing. This is particularly strongly pronounced in Oak. It is generally considered as inferior veneers except from Brown Oak, Silky Oak or Plane for example, where this figuring is in special demand.

Flares

Irregular veneer marking which generally is not desired.

Flashy Look

Expression for irregularly alternating spiral grain which causes more or less irregular markings in the veneer. Especially found in Black Cherry veneers.

Flat Cut

»Crown cut

Flitch

»Log-end

Flitch Stock

»Complete flitch

Four Pices Match

Special method used for burl veneers to produce highly decorative surfaces and patterns. Four veneer leaves in succession are turned twice and folded up once.

Furniture Grade

Veneer differing in length from 1.00 m to 4.00 m within one log which can be worked by the living room furniture industry.

G

Grading

Quality-related grading of veneers and the pricing of the various grades.

Grading Price

Price determination for a veneer log.

Gum

Black spots or patches which can occur in Black Cherry veneer.
They are not arranged in a regular pattern but can be positoned quite differently from one veneer leaf to the next.

H

Hairs

Fine hair streaks which particularly occur in Pear and Maple. They can be distributed over the entire surface of the veneer and are considered to be degrading in quality.

Half Round Cut

Type of conversion on the stay-log machine. Also called eccentric peeling.

Heart

The term used for the core wood area in veneer which
is different in color to the remaining part of the veneer leaf.

Heart

The annual ring structure of fast growing trees which produce the undesirable coarse marking in the veneer.

Horizontal Slicer

A slicing machine on which the counter movements of the log and knife are horizontal.
Bark occurring especially in burl or burr logs within the heart wood which has been overgrown.

J

Jet Drier

Veneer drying machine which dries the veneer in a continuous operation using hot air.

K

Kiln

Equipment for artificial drying of solid lumber with the help of computer-control.

Kiln-Dried Lumber

Solid wood which has been artificially dried in a kiln.

Knot

»Defect

L

Leaf

Veneer leaf.

Light Scratch

Very fine knife scratch which disappears from the veneer when the surface is sanded and as a result does not degrade the veneer

Lip Veneers

»Turning Veneers

Log

The section of a tree that can be sawn or used for veneer.

Log Run Parcel

A completely converted log parcel which is offered and sold as veneer with all its grades included in it.

Log-End Flitch

Term used for a log or part of a log in log or veneer form.

Lumber

Already converted solid wood.

Lumber Logs

Sawing quality logs.

M

Mesh Belt Jet Veneer Drier

»Jet drier

Mild Texture

Very fine and slow growing wood which produces a beautiful, even marking in the veneer.

Minerals

Dark patches or pockets in wood, especially occurring in the Ameri- can Oak.

Miscut

Veneer defect caused in the processing, generally leading to fluctuat- ing veneer thicknesses.

N

Number of Leaves

The number of veneer leaves in a bundle; generally 24 or 32 leaves.

O

Offcut

»Slab

Open Defect

Faults in veneer which produce holes.

P

Panel Length

Log and veneer lengths between 2.65 m and 3.20 m required by the panelling industry. Quality generally not as good as bedroom furniture length.

Parcel

A quantity of veneer prepared for the customer, often sorted into uniform qualities.

Partial Burl

»Cluster

Pepper

The thin black knots in yew veneer which are the typical figuring of yew veneer. The more pepper there is and the more regular this pepper is distributed over the surface the more valuable the veneer.

Pin Knot

Fine, overgrown pin knots which can only be seen with great difficulty on the bark. Appears as a black streak at the end of the log.

Pommele

Comes from the French word “Pommelé” (Pomme = Apple).
The term given to a regular veneer marking which resembles apples.

Press Drier

In this equipment the veneers are pressed between large rotating drums in addition to running through the jet drier to avoid waviness.

Pressure

Slicing fault which occurs when the gap between the knife and the pressure bar is too small or too large to clear the veneer.
Different thicknesses are given and to some extent bad cuts, too.

Pressure Bar

The bar opposite the knife. The gap between the knife and pressure bar is slightly narrower than the thickness of the veneer to generate the necessary counterpressure for a smooth cut.

Pressure Wood

»Compression wood

Q

Quartered

Conversion of veneer logs which have been quartered.
Produces quarters and half crowns.

Quarters

The bundles from a log which are given after opening the flitch (and, sometimes, cutting out of the heart) where the annual rings are cut radially at an angle of 90 degrees by the knife.
Typical stripy structure of the veneer.

R

Resin Pockets

Resin pockets in softwood which produce holes in the veneer and are thus degrading.

Rift

Quartered veneer flitches converted on the stay-log machine thus resulting in broad quarters being in sequence.

Rift, also Faux Quartier

Quartered flitches which are sliced on the knife in a normal way (see page 274). It produces half crown and quarters.

Rotary Slicer

Veneer cutting machine on which the log is clamped centrally when brought up to the knife while rotating so that the veneer leaves are peeled off spirally. Used for almost all burl veneers, Birdseye Maple or Birch.

Rough Cut

When slicing veneers rough patches are caused in the surface because of bad clamping of the log, setting the machine wrongly or by too strong fluctuations in texture. The cause can also be that the flitch is not hot enough.

S

Sap

The outer cell layer of the wood between bark and heartwood. The supply of water and nutrients to the tree is only through the outer row of sap cells. The remaining layers of cells in the sapwood only serve to store water. Color offset in sapwood. The sapwood is cut away in veneers.

Scratch

A notch which runs across the veneer leaf caused by a faulty knife. Typical slicing fault which makes the further use of the veneer question- able. Fine knife scratches are eliminated by grinding the knife.

Sequence

The sequence of veneer leaves within a bundle and the complete log.

Shake

Cracks in the lumber which follow the course of the annual rings. Part of trunks with this defect are not suitable for producing veneer or sawn timber.

Short Length

Log and veneer between 0.80 m and 2.00 m in length.

Single Bundles

Bundles of veneer taken out of their regular sequence within the log so that the sequence is no longer given. Generally lower qualities or quarters.

Slab

First side board of the round trunk which is cut off when preparing for slicing, generally used for firing or as waste wood.

Slip Match

A method of further processing veneers by which the consecutive leaves are only glued with the front side.

Stacked in Log From

The presentation of veneers stacked in their original log form.

Stain

Color changes in the log when same has been stored too long.
Direct radiation from the sun or too dry an atmosphere furthers this development. This is why logs for storage are waxed on the ends or sprinkled with water to avoid this development.

Starter Bundles

The first bundles cut from a log.

Stay-Log

Special veneer cutting machine in which the line of cut sweeps across the growth rings in a circular direction to give eccentric cutting.

Stripy

More or less clearly contrasting color stripes in the veneer which are generally considered as degrading. Known above all in the European Oak.

Sugar

»Hairs

T

Tan Bark

Water containing tannin acid in Oak logs which causes very dark coloring. Moreover, Oak bark is also not suitable for mulching because of its high tannin acid content.

Tegernsee Custom

A recognized standard work used by the wood industry in Germany in which the general regulations for the sawing and veneer industries are laid down (i.e. quality designations for sawn timber, tolerances regarding veneer thickness and leaves with defects, etc.).

Tension

Differences in density occur in a trunk through different growth zones and growth speeds (weatherside) which can lead to tension in the log. When a tree is felled cracking as a result of tension can occur making its use as veneer questionable. Problem especially with Beech.

Thick Cut

Veneers which are produced in other thicknesses than those laid down in the DIN Standard. Usual thicknesses are 0.9 mm, 1.2 mm, 1.5 mm, 2.0 mm and 2.5 mm. Larger thicknesses are usually produced as sawn veneers, i.e. cut on the block bandsaw.

To Grade

»To sort

To Grind The Knife

Small nicks and burrs on the knife blade are made smooth by using
a grindstone.

To Handle

Clipping and bundling of veneers after drying in preparation for sale. Also cutting out defects and clipping to length.

To Open

»To split

To Sort

Cutting a log to the required length and/or the desired method
of slicing.

To Split

The cutting out of the heart of a log when defects or rough patches occur during slicing.

Top End

Top end of a log (trunk or veneers).

Top Grade Log

Used to express a particularly high quality of a log.

Tree Burl

Burl wood in which the burl is developed above ground in the tree. Such burls are Oak, Ash, Poplar, Elm.

True Quartier

The cutting of the log into four quarters (see drawing page 273).
In the case of Oak this gives a higher portion of veneers with fine flakes. However, the yield is generally smaller than when converting in other ways.

Turning Veneers

The presentation of a log which is shown bundle by bundle.

Twist

Spiral-shaped growth of a tree caused by external influences,
for example, wind. Slicing problems can occur through the annual rings breaking away from each other thus causing open spots where the spiral grain is strongly twisted.

U

Underground Burl

Burl log where the burl development is in the root and the burl is either completely or partially under the ground. These logs have to be dug out to obtain them, an operation which is generally done by hand in order not to damage high quality burls. Underground burls are Myrtle, Walnut, Maple and Vavona or Redwood Burl.

V

Vat

The pit used for steaming or cooking logs. Earlier it used to be brick- built, today such vats are generally lined with steel or aluminium to make the pit more durable.

Vertical Slicer

Vertical slicer on which the log and knife counter movements are carried out vertically.

Void of Grain

Broad, structureless areas in crown cut bundles between their annual rings if the latter are coarse.

W

Wavy Grain

Wavy marking of the veneer which is given through such annual rings.

Wrapping

A process to “wrap” three-dimensional areas (profiles, curved edges, etc.) with veneers. To some extent this has replaced the molded edges made of solid wood.

Wrong Pricing

Price assessment of a log which is not conform with market prices.

Y

Yellow Gum

Yellowish brown patches in American Black Cherry, which are consi- dered to be degrading because they are still visible after surface treatment.