wood anatomy --- an introduction

phinds

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WOOD ANATOMY --- AN INTRODUCTION

If you have a "mystery wood" that you want to ID, there are a number of things you can do including sending a sample to the USDA and waiting months for a reply. A better method is to take good pics and post them here on Wood Barter asking if anyone can ID it for you. That often works, but not always. My wood ID web site has a full discussion of wood anatomy and shows how, with a pretty modest amount of effort, you might well be able do it yourself. BUT ... there is a lot of information there and the whole thing can be a bit intimidating to beginners so I've created a pair of light-weight introductory articles to give a quicker look at low easy it can all be.

The two articles are about how to use simple wood anatomy to do some pretty nifty analysis of the wood. One article is about growth rings and the other is about parenchyma. Parenchyma is less familiar to woodworkers than at least the rudiments of growth rings, but most folks are pretty startled when they realize the details that are available with so little effort to make both growth rings and parenchyma visible and useful in wood ID.

The two articles are to show the startling variety of characteristics that are readily visible in both parenchyma and growth rings and can be used to distinguish among various woods. The articles are at:






To make use of the information in the articles you need a 10X loupe, a small range of sandpaper (I recommend 100 grit, 220 grit, and 400 grit as an absolute minimum), and some elbow grease. Make a clean cut on the end grain of a piece of wood (sharp circular saw blade, for example, as opposed to a dull band saw blade), sand it progressively with the grits, getting rid at each grit of the scratches left by the previous grit, and then look at the resulting cleaned up end grain through the 10X loupe. You'll see what the articles are talking about. If you find the view a bit fuzzy you may not have applied enough elbow grease during the sanding process. Personally, I prefer a random orbital sander which avoids most of the application of elbow grease (and in my case helps avoid swear words as well).

One note about 10X loupe use. When I first got one, I thought you were supposed to put the wood a foot or so away from your eye and put the loupe close to the wood and adjust until the focus was right. Well, you CAN do that but it gives you an extremely, and unnecessarily, limited field of vision. The way you are really supposed to use them, it turns out, is to put them right up in your eye socket and move the wood very close to your eye. That doesn't give you any different magnification than the other way but it greatly expands the field of vision and makes the loupe much more useful.

The one other thing that is necessary, in addition to cleaning up the end grain and looking at it through a 10X loupe is a set of good pics showing what the parenchyma, growth rings, and pore structure looks like for different woods so you can try to find one that looks like the "mystery wood" you are trying to identify. One place you can find a fair number of such pics is in Hoadley's "Identifying Wood".

A significantly larger set of pics can be found on my web site at http://hobbithouseinc.com/personal/woodpics/_anatomy/_anatomy.htm which has over 3,000 useful pics of hundreds of species of the woods that are most likely to be encountered by USA woodworkers, and with a discussion of their types of parenchyma and growth ring characteristics. This is a small adjunct to my main site, which has over 45,000 pics of wood. The PICTURES of parenchyma for the different woods are under the "growth rings" section but the full discussion of the different types of parenchyma and how they relate to each other is in the "parenchyma" section.

Another extensive set of pics (but of limited utility since you have to already KNOW what wood you want to see the pics of, by botanical name) is the North Carolina State University site at http://images.lib.ncsu.edu/luna/servlet/view/search?q=="Modern Wood"

That site also shows orientations other than just the end grain. If you have a strong suspicion as to what a mystery wood might be, that site can be very useful in confirming/denying your guess if you know its botanical name.
 
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duncsuss

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Thanks Paul -- I'm going to take my time reading these articles in the hope that some of it sinks in :thanx2:
 
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