CENTRAL AMERICAN ‘TRUE’ MAHOGANY: B
There are a number of interesting characteristics found in this production which would normally be downgraded or cut out. We have therefore established a number of ‘new’ grades incorporating characteristics which would have been classed as defects in the past.
B: Illustrate some of the many different wild grains which include wild interlocked and curl figure, which can be used to a stunning effect in the right application.
Considering the large variety of grain variations and character found in our Mahogany production, we feel re-grading the downgraded stock is the way forward for this and other species in limited supply. FSC Certified.
Production: S/E, S/E PTW, DIM.
Swietenia macrophylla
Family: Meliaceae
Common/vernacular names: Honduras mahogany, Bay-mahogany or Bay-wood (old UK name for timber shipped from the ‘Bay of Belize’), Brazilian mahogany (contemporary UK name), Big-leaved mahogany, Caoba (main South American and USA name), Araputanga, Acajou (French speaking areas), Mogno, Aguano (Brazil and Peru) and several more depending on the country of origin.
Distribution: ‘Swietenia’ spp - are often termed as the only 'true' mahoganies and are widely distributed throughout Central and South America from Mexico southwards through the region of Central America including, Guatemala, Honduras and well into mainland South America where they are also found in Brazil, Peru and Bolivia.
The Tree: The trees are found scattered in all forest types from savanna to rainforest, but mainly in mixed forest types (hardwoods) often along river valleys where rich alluvial soils are found. 'Swietenia' spp are reported to be able to live for 350 years producing large trees which can attain heights of around 150' (46m) with trunk diameters up to 7’ (2m) or more being found. The trunk is generally very heavily buttressed, although long clear boles of 60' to 80' (18m to 24m) can be obtained. Due to its fast-growing nature it has been widely planted (in plantations) some of which are found in other parts of the world, including Fiji and Indonesia.
The Timber: General characteristics: The timber from this species can be very variable in colour and ranges from pale reddishbrown to a deep rich red. The darkest of these is said to resemble 'Cuban mahogany', S. mahogani (a CITES Annex B/ Appendix II listed species), which was traditionally revered as one of the finest cabinet woods and is now very scarce. The whitish to yellowish sapwood is about 25mm to 50mm wide and is distinct from the heartwood. Dark coloured gum and white deposits can be found in the pores of the timber. The grain is reported as being straight to interlocked and is renowned for producing very attractive figure, including wavy, mottled, curly, blister and roe figure. The texture can vary from fine to medium and uniform. A high, golden lustre is characteristic for this species. The timber is much prized by furniture manufacturers and is used for a variety of other highquality end uses.
Density/Weight: This species is very variable and there are a wide range of densities cited for mahogany, depending on where it is sourced from. According to 'The Wood Exchange' on the World Agroforestry's density website it is listed as having a (seasoned) density ranging from 485 to 840 kg/m3. This concurs with information in the TRADA 'Red book' No 2 - South America and lists the dry weight as 640 kg/m3 noting that in general material sourced from Brazil is some 20 per cent heavier than material from Central America. The publication 'Tropical Timbers of the World' reports that the basic specific gravity (oven-dry weight/green volume) for this species is 0.40 to 0.68 and the airdry density is listed as 30 to 52 Ibs/ft3.
Drying and Shrinkage: Central American Mahogany dries easily both by air-drying and with kiln-drying without appreciable warping or checking. Tension wood can sometimes be a problem which can result in longitudinal shrinkage in kiln drying. Reported to have a moderate air-drying rate with few or no drying defects. The radial shrinkage from green to oven-dry is reported to be 3.0% and for tangential 7.4%, with a volumetric rate of 7.8%. Movement in service is rated as small and after working it generally remains stable and does not warp.
Durability: The heartwood is rated as durable in resistance to fungi, but has little resistance against marine borers.
Preservation: The heartwood and sapwood are very resistant to impregnation with wood preservatives.
Strength: The bending strength, stiffness and compressive strength along the grain are good for its weight. This relatively high strength-weight ratios for the above properties made 'Swietenia' spp a popular choice for the manufacture of propellers. In general, the strength is reported to be about half-way between obeche and European beech.
Mechanical Properties
(Ultimate stresses based on testing, not to be used for design)
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Working Properties: A timber which is very easy to work with both hand and machine tools. Some grades that display figured material are susceptible to torn and chipped grain, and boards that are found to be 'woolly' should be worked with sharp tools. It has good nailing and screwing properties, can be glued and stained effectively and will give excellent results with normal finishing techniques. The timber also produces a good veneer.
Uses: Central American Mahogany is a very versatile timber which is widely employed for a variety of end uses. The timber of this species was extensively employed in shipbuilding for planking and deck fittings of small motor craft and yachts. It is also used for furniture and high-class cabinet work, internal and external joinery, flooring, musical instruments, and pattern making (body shell mock-up for Aston Martin Lagonda, for example). It can also be used for turnery and carving. Note: Swietenia macrophylla is included in CITES Annex B/Appendix II. Technical information supplied by TRADA Technology.
Certification: This is possibly our most important certified species as it is now on CITES LIST II. Our stock is produced by a number of indigenous communities in Guatamala and Honduras, whom we have worked closely with for sometime to produce the correct grade for our market. Their lumber is produced from a well managed forest concession, independantly certified in accordance with the rules of the Forest Stewardship Council A. C. All our Certified timber is processed through our Chains of Custody which are audited by BM TRADA Certification.
JBT Comments: It has taken a great deal of time and considerable effort to establish a reliable supply of correctly graded material. Although we feel we have now established the correct grade for our market, in order to avoid any problems, we re-grade and remeasure every board following kiln drying at our mill. Note: Related species: Cuban or Spanish mahogany Swietenia mahogani which for 250 years was the most cherished cabinet wood in the world, has now become of more historical importance than commercial significance due to indiscriminate felling in the 19th and 20th Century.
Grades and Specifications:All random square edge boards, graded to NHLA rules.
Specials: Selects and better 6ft and longer, average 8ft or 60% FAS better. 18 ins and wider. Mainly 1ins thickness.
Longs: Selects and better 8ft and longer, average 10ft or 60% FAS better. 6ins and wider allowing 5% 4ins/5ins and 10% 6ft/7ft. 3/4ins, 1ins, 11/4ins, 11/2ins,2ins, 21/2ins, 3ins and 4ins thickness.
Mediums: Selects and better 6ft and 7ft, 5ins and wider allowing 5% 4ins. Mainly 1ins thickness. Smaller quantities 11/4ins through to 4ins.
Shorts: Prime Quality 3ft to 5ft, 4ins and wider. Maximum 25% 3ft. Mainly 1ins thickness. Smaller quantities 11/4ins through to 4ins.
Staining/Paint Grade: No1 & No2 6ft and longer. 4ins and wider.Common with good overall specification. Mainly 1ins and 11/4ins.
Wild Grain Grade: A Selection of wild grains & curl figure: No1 & No2 common 6ft and longer. 4ins and wider with good overall specification. Mainly 1ins and 11/4ins.
Squares: FAS and Selects 11/2”x11/2”, 2”x2”, 21/2”x21/2”, 3”x3”, 4”x4”, 5”x5” and 6”x6”. 30ins and longer can be produced to order cross cut to length.
Stockholding: 6000 cubic feet in kiln dried or stock in kiln available in 3/4ins, 1ins, 11/4ins, 11/2ins, 2ins, 21/2ins, 3ins and 4ins thickness.
FIJIAN MAHOGANY
Swietenia macrophylla
This timber is produced in Fiji from plantation grown trees and being plantation grown it is not CITES listed. FSC Certification is in hand and should be granted in early 2005. The timber is similar in every way to Central American Mahogany but as it is plantation grown it tends to have a uniform bland grain. The grading and specification is also as Central American Mahogany, however, as plantation grown trees produce more timber with pin knots evident. In FAS pin knots are classed as no defect. Available in 1ins, 11/4ins, 11/2ins and 2ins thicknesses. We normally have kiln dried stock available FAS in ‘longs’ in 1ins thickness, approximately 1000 cubic feet.
