The A – Z of Trees : African Mahogany (Khaya genus) [Series]

Above photo By Andrew massyn – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4607724

Not to be confused with Sapele and Utile trees, the African Mahogany I’m focusing on in this article are from the Khaya Genus of trees, specifically:

  • Khaya Madagascariensis
  • Khaya Ivorensis
  • Khaya Grandifoliola
  • Khaya Anthotheca
  • Khaya Senegalensis

Colours of these woods vary greatly from a dark reddish brown to a rather pale pink.

 

Khaya_madagascariensis_02

The leaves of the Khaya Madagascarensis.

 

Above photo By Axel Strauß (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons

Khaya Madagascarensis

The Khaya Madagascarensis is found, no surprise, in Northern and Eastern Madagascar. An evergreen tree  it produces valuable timber and is known for its local medicinal use. It is reddish brown in colour and its timber uses include fine furniture, carving and its trunk is traditionally used for canoes. Unfortunately, it has been overexploited for its timber and has lost its natural habitat due to human activity, this has led to it being classified as endangered by the IUCN (International Union for the Conservation of Nature).

 

Khaya Ivorensis

The Khaya Ivorensis grows in Gabon, Cameroon, Cote D’Ivoire, Ghana, Nigeria and Angola; the tropical areas of Western Africa. The heartwood is a pale reddish brown and its timber is used for fine furniture and also for boat and ship construction. Its medicinal uses include being used in the treatment of whooping cough, diarrhoea, dysentery, back pain and rheumatism. Much like the Madagascarensis, Khaya Ivorensis is also under threat and is classified as vulnerable by the IUCN.

 

Khaya Grandifoliola

The Khaya Grandifoliola grows in Guinea-Bissau, Sudan and the Congo and is mainly a deciduous species in the dry season. The heartwood which darkens to a reddish brown after exposure is pinkish brown when first cut. The timber is used for fine furniture, veneer, ship building, toys, musical instruments and is traditionally used for furniture, canoes and household items. Medicinally the bark can be used as a washing cloth, as a treatment for the fever caused by malaria and also the treatment of gastric ulcers. A gum from the bark is used in the pharmaceutical industry as a slow release for tablets. Once again due to the high exploitation of this highly desired tree the IUCN list it as vulnerable.

 

Khaya Anthotheca

Also known as White Mahogany the Khaya Anthotheca is a semi deciduous tree found in Sierra Leone, Uganda, Angola and Mozambique. The heartwood can be a pinkish brown to copper red and is used for veneer and furniture making, traditionally the logs are carved out to form canoes. It can also be used to make charcoal. The bark is used traditionally to treat abdominal pain, gonorrhoea, colds and fevers. Lice can also be treated when oil from the seeds is rubbed into the hair. The bark is also sometimes used to treat ulcers and wounds and when pulverised is even used to combat male impotence and as an aphrodisiac. The IUCN rates the Khaya Anthotheca as vulnerable due to its heavy exploitation.

 

khaya_senegalensis_flower_02

The flower of the Khaya Senegalensis

Above photo By Forestowlet – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=33446266

Khaya Senegalensis

Found in Senegal, Sudan and Uganda, the evergreen tree Khaya Senegalensis has a dark red brown colour heartwood, sometimes with a hint of purple. The timber is used for fine furniture and boat building. Locally the wood is used for turning and railroad ties among other things. Once again the bitter bark is reported to be successful in the treating of fever but also syphilis. Bark extract is used as a disinfectant for various ailments. Unfortunately I have to once again type that this tree is also listed as vulnerable by the IUCN due to poor control of logging practices.

In Darwin, Australia there have been cases of falling branches of the African Mahogany killing people below when poorly maintained, as reported by NT News among others (African Mahogany in Darwin). One man was killed by a falling branch whilst on a golf course and a school boy was killed in the school playground in similar circumstances. It is theorised that planting African Mahogany trees in a wetter climate than their natural dry habitat causes them to grow larger faster, making them unstable.

What have I learnt about African Mahogany whilst writing this article? Well, mostly that its cultivation is poorly managed and this has unfortunately, though perhaps not unexpectedly, lead to it becoming a currently vulnerable species and perhaps soon to be endangered. I’ve also learnt that the Khaya genus produces great quality wood which is also stunningly gorgeous whilst also at the same time producing bark, oils and gum used in many kinds of medicines. Hopefully these trees will be around for many generations to come and I would think its our responsibility to make sure this is the case.

Thank you for checking out this blog post, please head on over to my Facebook Page to check out all the various things I get up to in the woodworking world.

Previous article in this series can be found here The A – Z of Trees : Acacia [Series]

 

Sources:

  • hardwoodtogo.net
  • ntnews.com.au
  • tropical.theferns.info
  • greenpeace.org.uk

 

The workbench flattening experiment (failure)

I’m a woodworker, and as such I like to find the quickest and most accurate way to complete tasks whenever I can . I’m not the best at flattening bench or table tops and although I haven’t had much practice with it, I found myself thinking of a non-power tool way to achieve something similar to the results one might get with a router sled.

plane

The enormously long plane.

Knowing that trying to use a hand router with a sled would take an incredibly long time to achieve the desired result, I instead turned to the idea of a very long plane riding over two level planks on either side of the workbench.

So I went about making a plane, for the first time mind, out of a long piece of straight scrap I had. Being that it was built from softwood I decided to use some old teak left over from a patio table parasol to keep the plane true. The wedge was made from ash and the iron was from an old wooden scrub plane I bought at a car boot sale (flea market).

I used a metal bar from an old socket set (which was almost entirely depleted) to hold the wedge in place. I needed a very firm grip as the iron would be protruding around a centimetre (3/8″) and cutting across the grain, sometimes removing 3 or 4mm of material at once (3/16″).

 

pla

Notice the material nicely sheared at the bottom centre of the photo.

It started to work, I was incredibly pleased! Then I was a little concerned when the iron rattled free, a little peeved when it came loose a second time and by the third or fourth time I was experiencing my misunderstanding of plane construction. Evidence of failure on YouTube – Experimental Prototype – Jig for flattening workbench top

I adjusted the wedge, trying all different kinds of angles and coming out with the same result. Nothing seemed to work, or at least nothing I could figure out.

Perhaps I needed a differently shaped wedge entirely, perhaps the mouth was angled incorrectly, maybe the bar to hold the wedge should’ve been made of wood for more grip. All those questions and more flooded into my head and I didn’t have enough time to tinker with it, I had other things to do , more crucial jobs to complete.

 

So, for now, the enormously long plane sits under my bench and I continue to work on my partially flattened and scarred work surface. I will come back to it one day and I am determined to make it work. Perhaps some time making other projects will give me a new perspective on solving the problem….perhaps I need to improve my plane building. Either way I love experimentation in woodwork and jigs and I would encourage anyone and everyone to experiment now and then. It’s always interesting to do something different and who knows, one day you might stumble upon a jig that others will use long after you’re gone.