Balsa info

About Balsa wood

We use hand selected aircraft grade balsa of the lightest variety from Equador and new Guinea.Balsa trees grow naturally in the humid rain forests of Central and South America and New Guinea. However, the small country of Ecuador, on the western coast of South America, is the primary source of model aircraft grade balsa in the world. Balsa needs a warm climate with plenty of rainfall and good drainage. For that reason, the best stands of balsa usually appear on the high ground between tropical rivers.

There is no such thing as forests of balsa trees. They grow singly or in very small, widely scattered groups in the jungle. For hundreds of years, balsa was actually considered a weed tree. They reproduce by growing hundreds of long seed pods, which eventually open up and, with the help of the wind, scatter thousands of new seeds over a large area of the jungle. The seeds eventually fall to the ground and are covered by the litter of the jungle. There they lay and accumulate until one day there is an opening in the jungle canopy large enough for the sun's rays to strike the jungle floor and start the seeds growing.

Balsa trees grow very fast. In 6 to 10 years, the tree is ready for cutting, having reached a height up to 90 feet tall and a diameter up to 45 inches. If left to continue growing, the new wood being grown on the outside layers becomes very hard and the tree begins to rot in the centre. Not harvested, a balsa tree may grow to a diameter of 6 feet or more, but very little usable timber can be obtained from a tree of this size.


The start of the balsa business was during World War I, when the allies were in need of a plentiful substitute for cork. The only draw back to using balsa was, and still is, the back breaking work that is necessary to get it out of the jungle. Because of the way the individual balsa trees are scattered throughout the jungles, it has never been possible to use mass production logging procedures and equipment. The best way to log balsa trees is to go back to the methods of Paul Bunyan - chop them down with an axe, haul them to the nearest river by ox team, tie them together into rafts, and then float the raft of balsa logs down the river to the saw mill. At the saw mill, the balsa is first rough cut into large boards, and then carefully kiln dried, and finally packed into bales for shipment. As a result of the balsa tree's fast growth cycle, both the quality and lightness of the timber obtained from a balsa tree can vary enormously depending upon the tree's age at the time of cutting.

The secret to balsa wood's lightness can only be seen with a microscope. The cells are big and very thinned walled, so that the ratio of solid matter to open space is as small as possible. To give a balsa tree the strength it needs to stand in the jungle, nature pumps each cell in the wood full of water until they become rigid - like a car tire full of air. Green balsa wood must therefore be carefully kiln dried to remove most of the water before it can be sold.


Finished balsa wood, like you would use for model aeroplane construction, varies considerably in density and grain. Balsa can be found weighing as little as 4 lb per cubic ft up to 24 lb or more per cubic ft (65 to 360 kg/m3). Commercially available balsa for models will weigh between 6 and 18 lb per cubic ft (95 to 285 kg/m3). Eight to twelve pound balsa (120 to 192 kg/m3) is most plentiful and is considered medium or average weight. The six pound (95 kg/m3) or less is considered "contest grade" owing to good lightness, although durability due to inherent weakness is not a priority and such light examples can be rare or even impossible to obtain. Light grade balsa is nominally 6 to 8 lb per cubic ft (95 to 135 kg/m3).


Switch Blade Fins


Factory / Showroom

7 Bayldon Dr, Raleigh, NSW, Australia


TEL / FAX: 02 6655 7007