The wonderful life of balsa wood.

Ochroma lagopus, is the scientific name for balsa wood! Balsa is a Spanish word meaning raft; it got its name for the excellent buoyant characteristics that it possesses.

While intern Samantha Weaver was doing research for the new balsa wood exhibit, she came across many facts about the life of balsa wood that were too extensive to put into the display, like the fact above. The information that was not used in the exhibit is, in general, not widely known about a wood that many have come in contact with in their lives. A few of these interesting tidbits of information are being shared here so that more people can be informed about this material.

From growing in humid rain forests to being used for building, balsa wood is a very unique and diverse material known for its light weight yet stable qualities, but how exactly does a balsa tree grow up to be that thin sheet of wood everyone, especially modelers, are so familiar with?

 

Typical shapes that balsa wood come in when bought at a store or hobby shop. (picture from woodtropis.com)
Typical shapes that balsa wood come in when bought at a store or hobby shop. (picture from woodtropis.com)

Looking at a balsa wood core one can see, like any other tree, it has growth rings. These rings play a crucial part in determining the characteristics of the balsa sheet that is cut out. Balsa has a heterogeneous composition, this means that one section of the wood will have specific qualities, while another section could be at complete odds with those characteristics. Cutting balsa wood is a precise procedure because of this. The different angle which a balsa tree is put into a saw defines the grain that comes out. If the angular rings are cut in a way that is with the grain it would produce “A-grain” type of balsa which is flexible but easily warped, across the grain produces “C-grain” which is very stiff, splits easily, but is most warp resistant, and the spare pieces of balsa left over are cut into “B-grain” which has a mix of qualities of the other two.

 

 

Balsa core and grain cut example.
Balsa core and grain cut example. (Picture from specializedbalsa.com)

 

 

 

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