Timber

of Dry Wt. of Timber

Moisture content after kiln Seasoning 5-6%
Moisture content in good timber 10 - 12 %
weight of the timber is to be reckoned at a moisture content 10 - 12 %
wt. of the Structural timber (beam & door) is to be reckoned at a moisture 10 - 20 %
Fungi genrated in timber if moisture contant more than 18 - 20 %
At Fibre Saturation point (FSP) of timber w/c 25 - 30 %
Fresh Timber Moisture Content 50%
Properties of Timber
Item Conifers [Softwood] Deciduous]
Leaf Shape Needle shaped Broad & Well Defined leaves
Annular Rings (Comp. strength) Distinct Indistinct
Medullary Rays (Shear Strength) Indistinct Distinct
Structure Resinous & Split Easily Non- Resinous
Shape Light Dark
Density/Strength Less/less More/More
Fibres Coarse grained fine grained
Example Chir, Deodar,Pine Babul Mahogony, Teak, Sal
Pith/Medulla - Heartwood- Sapwood- Cambium layer- Inner bark- Outer bark/Cortex
Specific Gravity of Timber [Elastic, Non Homogenous, Ansitropic] 1.54
Compressive Strength of Timber Max. parallel to Grain 30 - 70 N/mm2
Tensile Strength Max. Parallel to grain (2-3 Times) of Compressive Strength 90 - 200 N/mm2
Shear Strength Max. Perpendicular to grains 7 - 14 N/mm2
Elastic Modulus 0.5 to 1.2 x 104 N/mm2
E(parallel) = 10 -20 % more to E(perpendicular)
Deflection [Overhang, Cantilever, Simply Supported beam] l/180, l/240, l/360
Age of falling Tree 50 - 100 Year
Sap Content More (Undermature) Less than 50 year
Pith Content More (Overmature) More than 100 year
Annular Rings & Carbon Dating Age of Trees Timber

Liner Shinkage along Fibre 0.1 to 0.3 %

Shrinkage in Timber Radial Direction 3 to 6 %
Tengential Direction 7 to 12 %
Seasoning of Timber
Softwood - 6 Months Hardwood - 1 Year
Natural Air Seasoning
Economical Method less Shrinkage & Warping
Water Seasoning Prevention of twist & Warping
Boiling Very Quick Hot Steam & Expensive Method
Kiln Seasoning Large Scale at any Moisture Contant [Case hardening occurs]
Electric Seasoning Most Rapid & Uniform Seasoning [Timber may be Splited]
Chemical/Salt Seasoning Nacl, uria, Alumnium Sulphate [Corrosive Effect]
Neil Process Combustion of fuel in Chamber (Best Method)
Conversion of Timber [Unit -sqm]
Oridinary / Flat Sawing Tengential to Annular Rings, Twisting & Warping Most Economical
Quatar Sawing Cuts are Right Angles to Each Other where indistinct (Narrow) Medullary Rays
Tengential Sawing (Min. Strength) Tengential to Annular Rings at Right Angle to Each Other where indistinct Medullary Rays
Radial/Rift Sawing (Max. Strength) Radially / Parallel to Medullary Rays , High Wastage
Conversion - Radial >Ordinary>Quater> Tengential
Presarvation of Timber
Solignum Oil Preserve timber from White Ant
Oil Type Perservatives
Creosote Oil/Bethel Process Used Distilled Wood/Coal Tar [wooden Pole, Railway Sleeper] Pumped creosote 1N/mm 2
Arsenic Pentaoxide, Copper Sulphate, K2Cr2O7 [1:3:4] FRI Develop, For White Ants
Water Soluble Preservatives As-Cu Treatment [6;100]
6 part As Cu & 100 Part Water [Colorless & Transperent]
Organic Solvent Preservatives Painted, Waxed, Polished Pentachlorophenol, Benzene Hexa Chloride, DDT,
Sir, Abel Process Sodium Silicate , Borex & Sodium Arsenate, NH 3SO4 [Penetration 2 -4 cm]
Make Timber Fire Resistance Tarring Apply Hot Tar, [Fire Resistance] Railway Sleeper Dull smelll & Appearance
Charring Timber Burnt at 15 mm Depth
Method of Application of Preservatives
Injecting under pressure>Hot & Cold Treating> Dipping>Spraying>Brushing
 Defect in Timber - Due to Conversion/Cutting [CDWT]
Chip Mark Pointed mark placed by sawing tools
Diagonal grain Due to Improper Sawing/Diagonal Sawing
Torn grain Small Depression on the surface due to falling to tool
Wane Original Rounded mark on timber surface
Defects Due to Natural Forces develop in Timber [Abnormal Growth,Rupture of Tussues]
Burls/Excrescences] Abnormal growth due to shock or Injury
Ring galls Ring means bark, gall means abnormal growth & Curved Swelling due to Cut off branch
Cullus Soft Tissue which covers the wound of tree
Chemical Stain Color Change inner to outer
Foxiness Reddish or Yellow stains around pith due to lack of ventilation OR Overmatrity of Tree
Duruxiness White decayed spot Naturally
Twisted Fibre Twisting of young trees by fastblowing winds
Upsets Rupture due to improper falling of Tree
End Splits Greater Evaporation of Sap at the end grain of log
Coarse grain Cracks due to larger Annular rings spacing by Rapidly growth trees
Shakes [longitudinal Seperation] Most harmful
Star shake Split medullary Rays direction Bark to sapwood [wide at outside ]
Heart shake Split medullary Rays direction Pith to sapwood [wide at centre]
Cup shake Partially separate Annular Rings
Ring shake Entirely separate Annular Ring
bases of branch are broken or cut from tree [Reduce strength along the grain]
Knots Pin Knot - upto 6mm small knot - 6 - 20mm
Medium knot - 20 - 40 mm Large knot - more than 40 mm
Defect due to Seasoning
Bow Curvature along length
Cup Curvatue along lateral direction
Warp Timber has twisted out of shape
Twist Spirally distorted along length
Checks Longitudinal Cracks in wood perpendicular to Annular Rings
Honey combing During Drying various Radial or Circular Crakcs
Case hardening Timber External surface in Compression & Internal in Tension
Diseases in Timber
Dry Rot Timber to fine powder from lack of ventilation & Fungi
moisture content above 20 %
Fungi formation condition
Presence of Air & warmth for growth of fungi
Note - Bluw stain, sap stain, brown Rot, Heart Rot, White Rot are also caused by fungi
Wet Rot Caused by Alternate Wet & Dry Conditions, Greyesh timber color
Defects Due to Insects
Beetles make pin hole on timber about 2 mm dia
Marine bores found in salty water
Termite these are dimak [white ants]

Products of Timber
Bolt Wooden log length < 1.25 m
Post/Pole/Span Long wodden log Dia/Side < 30 cm
Thickness > 50 mm
Scantling [mota or chota]
Length < 200 mm
Thikness < 50 mm
Plank [patla or chowda]
Width > 50 mm
Thikness < 50 mm
Batten [patla or not chowda]
Width < 50 mm
Thikness < 50 mm
Board [patla or jda chowda]
Width > 150 mm
Quartering A Square piece of Timber
Baulk A Roughly Square piece obtained by only bark & sapwood
 Industrial/Artificial Timber
Sun Mica Thin hard decorative sheets [0.6 to 1.5 mm]
Veneer Thin sheet of timber cut by sharp cutter [0.6 to 6 mm]
Succesive layers of veneer at right angle to each other to get same strength in both direction
Plywood
No. of venner [3 - 13] odd No. [Teak Walnut, Rosewood] [No Expension & Shrinkage]
AA plywood Top & Bottom Face both same High Quality
AB plywood Top Face High Quality & Bottom Face Low Quality
BB Plywood Top & Bottom Face both High Quality
Plywood Thin veneers glued in Right Angle Direction to each other Door, Panels Furniture
Medium Density Fibreboard[MDF] fine wood fiber bounded with wax/resin underpressure Moldings, Shelving, Cbinet
High Density Fibreboard[HDF] Compressed wood fibres into a Dense Board Wall Panel, Drawer Bottom Cbinet Block
Practicle/Chip Board Wood Particle/Chips are bounded with Synthetic Resin Low Cost Furniture, Desk [Less Durable,Light wt.]
Laminated Veneer lumber[LVL] Layers of Veneers glued in the same Direction Beams, Headers, Door/Window Frame
Block Board Softwood Strips are Sandwiched b/w Veneers Table Chair, Door, Window
Oriented Stand Board [OSB] Strands of wood arranged in Layers and Compressed Roofing, Flooring [Strong, Water Resistant]

Composition of Paints
Metalllic oxide, Opaque paint film & possing binding props.
White Lead- Suitable for wood Surface
Base
Red lead - Suitable for Iron Surfaces[Corrosive resistance]
Lithophone - Only for Interior Surface
create liquid suspension & binder for other ingredients
Vechile/carrier/Binder/Drying oils
Linssed oil, tung Soil, Poppy Oil, Nut Oil, Varnish
Inert material to improve Strength & Hardness also Reduces Cost
Extenders/Extrude/Fillers Main purpose Pigment Volume Concentration
/Adulterants [Max. Qty - 25 %]
Gypsum, Tale, Calcium Carbonte, AlSiO2 & Mg SiO2
Volatile solvent adjust consistancy of paint, thin paint & Increse opaqucity
Thinner/Solvent/Diluent Turpentine, White Spirit, Neptha, Benzine, Petrolium
Turpentine best - High solvent power, High Rate of Evaporation, Flattening Props.
Oxygen carrying catalyst Increase Drying power of Vechile
Driers [Max. 8 %] Litharge, Lithophone, Red lead, sulphte
It reduces Elasticity & flaking failure
provied Color & opacity and appearnce to paint
Pigmet
Green color - Copper Sulphate White Color - Zinc
Types of Paint
Enamel Paint [Zn oxide, White lead] [Vechile - Varnish] for wood work, water & Acid resistance [Internal & External Works]
Aluminum Paint [ Vechile - Varnish] for wood & Iron, Visible in Darkness, corrosion & Weather Resist
Water Paints/ Distemper/wall paint [vechile - water, base - chalk lime, white chalk] only Interrior Surface white washing
Cement paint/snowcem/snowcrete [vechile - water, base - white portland cement] It is water proof paint
Bitumenous paint [vechile - Spirit/neptha, base - Asphalt bitumen] used Iron under water
Asbestos/Fire proof paint [Vechile spirit/neptha, base - fibrous material] water & fire proof
Cellulose/Duco/Spry Paint [Vechile - All type, base - Nitro-cellulose] evaporate Quickly used in Airoplane, Automobile,
Putty Powdered chalk + Linseed oil [High plasticity]
Varnish [Resin + Solvent + drier ]
[Resin+Turpentine+ Linseed Oil], Most Durable Varnish for External & Internal surfaces
Oil varnish
Oil used is Linseed Oil, Require Frequently cleaning form Dust & Dirt
Asphalt Varnish [Asphalt + Turpentine + Linseed Oil], Used Shop fabricated steel work
Water Varnish [Shellac+ Hot water] Borox, Soda potash Used
[ Lac/Shellac+ Spirit] Easily affected by Weathering action
Spirit Varnish/Polish French polish Lacquer is used
Wax polish [bee wax + Turpentine]

Paint Applying in three Coat Priming Coat - Intermediate Coat - Finishing Coat
Munsell System Classify colors according to hue, lightness & Darkness, Chorma