Balsa wood comes from Ochroma Lagopus. These trees are native to the rainforests of Central and South America. Here, these trees grow naturally from Guatemala in Central America to the northern and western coasts of South America till Bolivia. Ecuador on the western coast of South America is the No. 1 source of model aircraft grade balsa worldwide. This wood is ideally named as Balsa in Spanish means raft, referring to its excellence in floatation while in Ecuador it is also called Boya or buoy, referring to its high buoyancy.
This world famous wood type is renowned for its lightness and softness. It ranges between four and seven kilos in weight per cubic foot. Despite this, it is classified as a hardwood, only for its broad leaves and the fact that it is not a conifer.
Its salient feature is that it is extremely lightweight and versatile, and therefore finds applications in everything under the sun, ranging from making model airplanes and gliders to sports equipment and much more.
Color and appearance: Balsa’s heartwood is identified as a pale rust in color and is not part of commercial timber. Most of its boards come from its sapwood, which could be off-white in color or tan, sometimes with a tinge of pink or yellow.
Grain: Its grain is straight and it has a medium texture with a subdued lustre. It is characterized by three types of grain:
A-Grain: This kind of sheet Balsa is distinctive for its long fibres that is apparent to the naked eye as long-lined grain. In sheets, Balsa is very flexible and can also bend at the curves very easily. It also warps very easily.
B-Grain: In sheet form of this grain, Balsa displays some of the qualities of the A-Grain and the C-Grain. The grain lines here are shorter than those of A-Grain Grain and is stiffer to touch across the sheet. It can be used for a variety of purposes.
C-Grain: In sheet form, this grain of Balsa has a beautifully mottled look. It feels stiff to touch across a sheet and can split very easily. However, by taking care to use it well, it can help build light and strong models. Of all three kinds of grain, this one is the most resistant to warping. It is often known as quarter grain.
End grain: Its end grain has large pores in random arrangement.
Rot resistance: Its sapwood is termed perishable and it is also prone to insect attack.
Ease of working: It is easy to work with and is not so sharp that it dulls the sharp blades of cutters. However, its low density can bring about fuzzy surfaces when using blunt cutters. To join sheets or planks of Balsa, glue is preferred over nails. It also lends itself very well to staining and finishing, though it may drink up a lot of material in the first few coats.
Odor: It does not have any distinctive odor.
Allergies: Balsa does not cause severe reactions, though skin irritation is not uncommon.
Pricing: Balsa that is high in quality and low in density is expensive to buy. However, when large boards of this wood are bought at dealers, the cost is reasonable.
Sustainability: Balsa wood grows fast and without the use of fertilizers, it can also grow sustainably. The regions where it is natively grown, it is a weed tree and since it does not live long, it needs harvesting, making it ideal for plantation growing without impacting Nature negatively.
There are several uses of balsa wood, such as:
- Aircraft: Balsa wood shot to fame when it was used to construct British de Havilland Mosquito combat planes during World War II. It can be very successfully used to make light and stiff structures as model bridge tests and to make light wooden aircraft. These days, it is used in planes to construct passenger compartments.
- Model aeroplanes: At hobby stores, you can find a lot of products made from Balsa, such as sticks and blocks, particularly for hobbyists who wish to create model airplanes like this one over here. The chief attraction to this wood are its salient features–it is lightweight, strong and flexible.
- Table tennis bats: Table tennis bats are made by placing laminated balsa sheets between plywood layers.
- Boats and surfboards: Watercraft like boats and surfboards are made by placing it between layers of fibreglass to buttress its flexibility and strength, while also adding to the watercraft’s overall weight.
- Furniture: Designers are increasingly turning to balsa wood as a material for furniture, lauding its sustainability as a fast-growing tree along with its aesthetic properties.
- Good insulator: It is very good at insulating refrigerators and homes, thanks to its singular thermal properties.
- Musical string instruments: Designer of musical instruments, particularly string instruments like violins, use balsa for its excellent acoustics.
- Model bridges: It is useful for students of physics and engineering who need to build model bridges.
Advantages of balsa wood
- Balsa wood is lightweight, soft and highly buoyant.
- It is lighter than cork and thus ideal for life preservers and lifebelts.
- Being light and soft, it is perfect for model building. Since cork is low density, it is also very strong and can be used to make wooden fishing lures.
- It is a good insulator and is therefore used in refrigerators and cold storage rooms. Its insulating properties are also extended to sound devices.
- Despite all its individual characteristics and benefits, balsa wood is surprisingly affordable.
- It grows fast and is easily available wherever it is natively grown.
- It is easy to cut, shape and carve, rendering it ideal for craft work and model making.
- It retains a lot of water in it, making it very strong.
Disadvantages of balsa wood
- It is highly flammable.
- It is not waterproof.
Now that you know all about Balsa wood and its distinctive properties, perhaps you too will choose it in future for any of the uses mentioned above.