Friday, July 15, 2011

Aeromodeller 1958-05


After all my talk about Balsa trees, I thought it would be more complete if readers could see a section of a Balsa tree, so 1 have specially imported some logs from Ecuador and by the time this goes to print most of our Accredited Dealers should have a section of these logs to show you. If you will look at the photograph taken of a pile of these logs you will notice the very great variation in shape and size. If you look carefully you will be able to see the pith heart of the tree and how it varies in position in the different logs. In the other two pictures, I have drawn in ink the growth rings on a section of a Balsa log and also indicated on photo B, by dotted lines, the kind of planks of wood that might be cut from a tree like this. I have deliberately chosen a log with the pith core, which is the growth centre of the tree, very much to one side. You will notice how year by year the tree has put on much more wood on one side than the other and, as you would expect, the wood on this side is much lighter than on the other. You will, therefore, see that pieces of lumber cut from this tree must have a great variation in the density of the wood, both in the different pieces and from side to side of the individual piece.