"Crotch" Wood

In a previous article, I spoke about Burls in wood. A while ago I had someone ask me what is Crotch Mahogany. Where Burls are as a result of growth, of which the cause is often unknown, Crotch, or Flame Mahogany as it is also sometimes referred to, is a result of the way the tree grows. It is where the tree forks and a V is formed, much the same as the crotch of humans. If the tree is cut in the torso, just below the chest and just above the knee (as would be on a person), the wood if then cut or sliced into veneer, would result in the grain forming a type of V or U and the grain would be somewhat more pronounced forming, if you used your imagination, what may represent a flame. Crotch is not only found in the Mahogany species, but in any tree. The size of the tree would matter as the tree would have to be of a fair size for there to be adequate growth to result in the pattern to be of significance.

It is a very distinctive and beautiful feature that is often sought after when making furniture. It would often be used in panelling, door panels, table tops, somewhere where the space or sizes large enough to allow it to be shown off. In solid it would be somewhat of a waste, because you would only see one surface and the repeating visual pattern would be locked in the rest of the piece. So, in this case it would make sense to slice it into veneer, or cut it into thin planks/pieces. It is not often used in guitar making as the size of the instrument would not show off the full beauty, but having said that, if one finds a reasonable specimen and the size and pattern is good, then, a very unique instrument could be made with a good aspect of added value. The visual impact is often highlighted when book matched, as in most veneering pieces; the mirror image often improves the effect. I will discuss book matching in a future blog.

Burl Woods

What is Burl, or Burr in wood?

It often forms on a tree as a type of nodule or lump and in that lump is an intricate growth system which results in a beautiful, attractive unique pattern when the wood is cut into planks, or sliced into a veneer. Mostly, the burls grow beneath the ground, but when they are above ground level, they are quite noticeable in the form lumpy protrusions on the trunk of the tree. Obtaining the burl wood is expensive because of it scarcity.

What causes this?

Well, no one can say for sure, but it is almost like a type of malignancy or disease that forms causing the tree to create this lump or effect. Sometimes insect infestation or mould infestation can also cause this. In a nutshell, the burl will result when the tree undergoes some kind of stress.

The results of this burl are visually very attractive and very unique and can sometimes give the wood a very wild, busy look. Some common species you may have heard of is, Walnut Burl, Bird's Eye Maple, Elm Burl, Oak Burl, Poplar Burl and there are many others.

Where is it used?

This busy, wild grain, makes the wood very dense, which also makes it much harder than the species that it originates from. This makes it very sought after for making bowls and in the past, it was used for mallets, mauls and chisel handles used for hammering. Today it is used for instruments,inlays in tables, door panels, wooden wall paneling, dash boards in up-market cars, boat building etc. The burl wood is difficult to work with, because of its intricate knurled grain that has no specific direction and when sliced into veneer, it can easily buckle and crack or split. Having said all this, the end result, when it has been used in guitar making, furniture, panelling,or other types of instruments, the result is truly stunning, with a beautiful depth and lustre, as well as being unique, something that only nature can provide.

Engelmann Spruce in Guitar Making

Of the many Spruce trees, Engelmann Spruce is one of the woods used in Guitar making as well as other instrument making. Engelmann spruce originates in Western North America - extends northward at higher elevations in the Cascade, Monashee, Selkirk, and possibly the Rocky Mountains, as well as the highlands surrounding the Interior Plateau. Picea engelmannii is a medium-sized to large evergreen tree growing to 2540 m (82131ft) tall, exceptionally to 65m (213ft) tall, and with a trunk diameter of up to 1.5m (4ft, 9 in).

Engelmann spruce is of economic importance for its wood, harvested for paper-making and general construction. Wood from slow-grown trees at high altitude has a specialised use in making musical instruments such as acoustic guitars, harps, violins, and pianos.

Engelmann Spruce is usually a cream to almost white color, with an occasional hint of red. Easy to work, as long as there are no knots present. Glues and finishes well, though it can give poor (blotchy and inconsistent) results when being stained due to its closed pore structure. A sanding sealer, gel stain, or toner is recommended when coloring Spruce.

With regard to sustainability, this wood species is not listed in the CITES Appendices, and is reported by the IUCN as being a species of least concern.

Engelmann is also known as white, European or German spruce, although they are technically different species. It is usually visually distinguishable from Sitka by its creamier complexion. The high quality of Spruce amongst all species is running out and guitar makers worldwide, are having to compromise the quality to what is available.

Engelmann has a mature tone, and yields a slightly richer midrange than Sitka, which makes a guitar sound a bit older. Old growth Engelmann tends to have a sonic attribute of smoothness or refinement to it, but the days of older growth Engelmann trees are essentially gone for now.