Gonioma kamassi (Kamassi boxwood)


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Scientific Name
Gonioma kamassi

Trade Name
Kamassi boxwood

Family Name
Apocynaceae

Common Names
African boxwood, Boxwood, Cape boxwood, East London boxwood, Kamassi, Kamassi boxwood, Kamassie, Kamassihout, Knysna, Knysna boxwood

Regions of Distribution
Africa

Countries of Distribution  [VIEW MAP]
South Africa, Swaziland

Common Uses
Agricultural implements, Boat building (general), Carvings, Engraving, Flooring, Food containers, Furniture, Handles, Joinery, Mathematical instruments, Millwork, Musical instruments, Precision instruments, Shade rollers, Shafts/Handles, Shuttles, Sills, Specialty items, Sporting Goods, Textile equipment, Tool handles, Turnery, Vats, Vehicle parts

Environmental Profile

Status unsure as a result of insufficient information
Extinct, Endangered, Vulnerable, or Rare in some parts of its natural range
Data source is World Conservation Monitoring Center

Extinct, Endangered, Vulnerable or Rare within its natural growth range in Swaziland. Its status in South Africa is currently unknown because of inadequate information

Distribution Overview
Confined mainly to the midland coastal districts of South Africa.

Heartwood Color

Brown
Red
Yellow
Purple
Orange
Pink
Yellow to golden-yellow to orange
Pale brown
Yellowish brown
Greenish to greyish

The heartwood is a uniform yellow or yellow-brown color. The presence of incipient decay may produce a greenish tinge

Sapwood Color

White
Yellow
Brown
Red
Green/Grey
Same as heartwood
Color not distinct from heartwood

Grain

Straight
Weak (figure)
Figure
Even
Crossed
Spiral

 

Straight
Weak figure
Spiral grain occasionally
Even

Texture

Medium
Coarse
Fine
Fine
Very fine

Luster

Medium

Natural Growth Defects
Incipient decay often discolors the center of logs

Natural Durability

Susceptible to insect attack
Moderately durable
Non-resistant to powder post beetles
Non-durable
Resistant to termites
Durable
Non-resistant to marine borers
Non-resistant to termites
Perishable
Resistant to marine borers
Durable
Resistant to attack from powder post (Lyctid & Bostrychid) beetles
Sapwood is susceptible to wood staining fungal attack
Pinworms (ambrosia beetles) often present in the standing tree
Pinworms (ambrosia beetles) may be present in the felled log
Pinworms (ambrosia beetles) are commonly present
Little natural resistance

Untreated wood is prone to staining and severe splitting.

Odor

No specific smell or taste

Toxicity

Some toxic effects
Unspecified toxicity
Respiratory effects
Poisonous
Sawdust can cause ear, eye or nose irritation in some individuals
Dermatitic effects

Kiln Schedules

Dry at a slow speed
UK=C US=T3C2/T3C1 Fr=3
UK=B US=T2C2/T2C1 Fr=2
UK=A US=T2D4/T2D3 Fr=1
T3 – C2 (4/4); T3 – C1 (8/4) US

Drying Defects

Checking
Splitting
Distortion
Internal Honeycombing Possible
Severe surface checking
Severe end splitting

Rapid drying may cause excessive surface checking and severe splitting.

Ease of Drying

Fairly Easy
Slowly
Moderately Difficult to Difficult
Easy
Dries well
Dries slowly with little degrade

Timber is reported to season well, with few defects if dried slowly.

Kiln Drying Rate

Naturally dries slowly
Slow
Drying rate is fairly rapid to fast
Drying rate is slow

Tree Size

Sapwood width is 0-5 cm
Bole length is 0-10 m
Tree height is 30-40 m
Tree height is 20-30 m
Bole length is 10-20 m
Tree height is 40-50 m
Trunk diameter is 100-150 cm
Trunk diameter is 150-200 cm

The timber is available in logs of small sizes only, often up to 10 inches (25 cm) in diameter. Logs are often fluted and of poor form.

Product Sources
The timber is exported from South Africa in small quantities at a regular rate. It is usually shipped in squared billets cut to small sizes for manufacture.

Comments
General finishing qualities are rated as good

Blunting Effect

Blunting effect on machining is moderate
Medium effect

Boring

Fairly easy to very easy
Fair to good results
Very good to excellent results
Good (75+ pieces out of 100 will yield good to excellent results)

Carving

Fair to Good Results
Fairly Easy to Very Easy
Works well with hand tools

Cutting Resistance

Easy to saw
Gum-Up
Fairly Difficult to Very Difficult to saw
Moderate to saw
Cutting Resistance with dry wood is easy
Easy to saw

Logs left exposed for long periods of time tend to develop deep splits along their entire length. Combined with spiral grain, this may cause a high percentage of waste factor during conversion.
Waste Factor

Gluing

Fairly Difficult to Very Difficult
Fair to Good Results
Fairly Easy to Very Easy
Fairly difficult to glue
Easy to glue

Mortising

Fairly Easy to Very Easy
Fair to Good Results
Very Good to Excellent Results
Fairly Difficult to Very Difficult
Good mortising properties

Moulding

Fairly Easy to Very Easy
Fair to Good Results
Very Good to Excellent Results
Fairly Difficult to Very Difficult
Wood has tendency to ride on cutters
Good moulding properties

Movement in Service

Fair to Good Stability – Medium Movement

Nailing

Poor to Very Poor Results
Fair to Good Results
Fairly Easy to Very Easy
Very Good to Excellent Results
Difficult to nail
Tends to split during nailing

Planing

Fairly Easy to Very Easy
Fair to Good Results
Very Good to Excellent Results
Fairly Difficult to Very Difficult
Planes well, to a good finish
Difficult to plane

The material planes with some difficulty. It has a tendency to ride on cutters.

Resistance to Impregnation

Resistant heartwood
Permeable sapwood
Permeable heartwood
Resistant sapwood
Heartwood is very resistant
Heartwood is extremely difficult to treat with preservatives

Resistance to Splitting

Very Poor

Response to Hand Tools

Easy to Work
Responds Readily
Fairly Difficult to Difficult to Work
Easy to machine
Moderate working qualities
Good response to hand tools
Difficult to machine

Routing & Recessing

Fair to Good Results
Fairly Easy to Very Easy
Good in both routing and recessing.

Sanding

Fair to Good Results
Fairly Easy to Very Easy
Easy to sand
Sanding finish is excellent

Screwing

Possible if prebored
Screwing yields good results
Good screw holding properties

Turning

Poor to Very Poor Results
Fairly Easy to Very Easy
Very Good to Excellent Results
Easy to turn
Turns well

The timber is reported to turn exceptionally well, and is a preferred stock in making precision instruments. Also used for engraving and shuttles.

Veneering Qualities

Suitable for peeling
Veneers easily
Suitable for slicing
Difficult to veneer
Veneers moderately easy
No drying degrade

Steam Bending

Fair to Good Results

Polishing

Fair to Good Results
Very Good to Excellent Results
Satisfactory results
Good results
Easy

Staining

Fair to Good Results
Very Good to Excellent Results
Fairly Easy to Very Easy
Finish is generally satisfactory
Finish is generally good

Strength Properties

Density (dry weight) = 53-60 lbs/cu. ft
Modulus of Elasticity (stiffness) = high
Max. crushing strength = high
Bending strength (MOR) = high
Shrinkage, Tangential = large
Shrinkage, Radial = large
Shearing strength (parallel to grain) = medium
Hardness (side grain) = hard
Shrinkage, Tangential = fairly large
Shrinkage, Radial = fairly large
Hardness (side grain) = very hard
Density (dry weight) = 61-67 lbs/cu. ft

Numerical Data

Item Green Dry English
Bending Strength 13576 21177 psi
Density 57 lbs/ft3
Hardness 2653 lbs
Maximum Crushing Strength 6899 10339 psi
Shearing Strength 2385 psi
Static Bending 11143 psi
Stiffness 2167 2544 1000 psi
Specific Gravity 0.67 0.85
Weight 55 44 lbs/ft3
Radial Shrinkage 5 %
Tangential Shrinkage 8 %
Item Green Dry Metric
Bending Strength 954 1488 kg/cm2
Density 913 kg/m3
Hardness 1203 kg
Maximum Crushing Strength 485 726 kg/cm2
Shearing Strength 167 kg/cm2
Static Bending 783 kg/cm2
Stiffness 152 178 1000 kg/cm2
Specific Gravity 0.67 0.85
Weight 881 705 kg/m3
Radial Shrinkage 5 %

References
Banks, C.H., Schoeman, J.P., Otto, K.P.,1977,The Mechanical Properties of Timbers with particular reference to South,Africa,South African Forestry Research Institute Bulletin,(Ed.,Schoeman, J.P. 1973 & Otto K.P. 1976,No.48

Banks, C.H.,1954,The Mechanical Properties of Timbers with Particular Reference to those,grown in the Union of South Africa,Journal of the South African Forestry Association,No. 24 pp.44-65,[South,African Forestry Journal]

Bolza, E., Keating, W.G.,1972,African Timbers – the Properties, Uses and Characteristics of 700 Species,C.S.I.R.O. Div. of Building Research

Bolza, E.,1976,Timber and Health,Div. Building Res. C.S.I.R.O. Australia

Chalk, L. et al.,1935,Fifteen South African High Forest Timber Trees,Forest Trees and Timbers of the British Empire, Imperial Forestry,Institute, Oxford,Part 3

Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison.

Cox, H.A.,1939,A Handbook of Empire Timbers,Forest Products Research Laboratory, Princes Risborough

Desch, H.E.,1948,The Boxwoods,Wood,13(5,pp130-1

Farmer, R.H.,1972,Handbook of Hardwoods,HMSO

Forest Products Research Laboratory, U.K.,1955,Kiln-Drying Schedules,Forest Products Research Laboratory, Princes Risborough, Department of,Science and Industrial Research, Building Research Establishment Leaflet,No.42

Forests Products Research Laboratory, U.K.,1956,A Handbook of Hardwoods,Forest Products Research Laboratory, Princes Risborough, Department of,Science and Industrial Research, Building Research Establishment

HMSO. 1972. Handbook of Hardwoods. 2nd Edition. Revised by R.H. Farmer. Department of the Environment, Building Research Establishment, Princes Risborough Laboratory, Princes Risborough, Aylesbury, Buckinghamshire.

Howard, A.L.,1948,A Manual of Timbers of the World.,Macmillan & Co. Ltd. London 3rd ed.

Palgrave, K.C.,1977,Trees of Southern Africa,Cape Town South Africa

Patterson, D.,1988,Commercial Timbers of the World, 5th Edition,Gower Technical Press

Record, S.J., Mell, C.D.,1924,Timbers of Tropical America,Yale Univ. Press

Scott, M.H. 1953. Utilization Notes on South African Timbers. Bulletin No. 36. Department of Forestry, Union of South Africa. The Government Printer, Pretoria, South Africa.

Scott, M.H.,1935,Weights of South African Growth Timbers,South African Department of Agriculture and Forestry Bulletin,No.145,Forest Products Institute, Forestry Series No.1

Scott, M.H.,1953,Utilisation Notes on South African Timbers,South African Forestry Department Bulletin No.36

Sim, T.R.,1906,The Forests and Forest Flora of Cape Colony,Taylor & Henderson, Aberdeen

Sim, T.R.,1921,Native Trees of South Africa,Union of South Africa Department of Mines and Industries Memoir No.3

Takahashi, A.,1978,Compilation of Data on the Mechanical Properties of Foreign Woods (Part,III) Africa,Shimane University, Japan, Research Report on Foreign Wood No. 7

Titmuss, F.H.,1965,Commercial Timbers of the World,Technical Press Ltd., London, 3rd edition

Wood, B., Calnan, D.,1976,Toxic Woods,British Journal of Dermat 94 Suppl. 13