A Craftsman's Guide to Wood Technology - Understanding Wood

Simply put, "Understanding Wood" is the only truly comprehensive, scientific treatment of the properties and behavior of wood, specifically written with the craftsman in mind, by the absolute. As professor of wood technology at the University of Massachusetts at Amherst since 1962, Bruce Hoadley is a (and perhaps THE) leading expert on the science of wood. Presented in a slightly simplified scientific manner, which non-scientist craftsmen can easily understand, Hoadley's book provides almost every scrap of knowledge we have on wood of potential interest to the craftsman (which is virtually everything). Hoadley is himself a craftsman, a sculptor who carves wood, and so has a keen understanding of the special challenge of working in a material which is essentially alive, which is to say highly varied between and even within species and always changing. For most craftsmen in wood, "Understanding Wood" will be among the most useful books on the shelf. It's a masterpiece, which every woodworker should own.

"Understanding Wood" is an excellent book. It is packed full of useful information, such as how to dry wood and what is happening inside a board during each step of the process, how to orient grain in order to minimize joint stress due to changes in humidity, what is happening at the molecular level when you cut or sand wood, why it cups, cracks, or twists and how to avoid these problems, and so on. The breadth and depth of knowledge displayed here is amazing.

This book is well-written and enjoyable to read. Despite the fact that it is full of so much technical information, Mr. Hoadly is an artisan at heart and this adds a great deal of warmth to his writing. I liked reading about his personal experiences, his mistakes as well as his successes. Personally, I find it comforting that someone with such an expert understanding has made some of the same goofs that I have. I read it from cover to cover. (Okay, so I glossed over most of the equations.)

"Understanding Wood" is a great reference manual, full of tables, charts, and pictures. If there's something you want to know about a particular species, such as strength properties, stability with changes in moisture, ability to accept penetrating finishes, etc., it's easy to look up. I highly recommend this for your workshop.

This second edition is "completely revised and updated". This does not go for the text: of the text of the first edition better than 99% is present here, only minutely altered. A six-page new chapter (#16) on Engineered Wood has been added. The chapters on panels and boards are somewhat revised as is the chapter on Finding Wood. In the other chapters text has been swapped around, but has not been changed.
The "revision" is mostly in the layout and pictures. The line drawings are substantially unaltered, but of the photographs most were replaced by color photographs of a generally very good quality.
As a wood anatomist my attention was drawn to the chapter on identifying wood. Since this subject is covered in much more dept in "Identifying_Wood" (same author, same publisher) there were two ways to go, either 1) eliminate the overlap by replacing this with a presentation of woods by pictures of longitudinal grain (as in "The_Good_Wood_Handbook") which would have been user-friendly and would have had my preference or 2) upgrade this book to the level of its companion. The latter strategy has been chosen and the black&white end grain pictures of the 1st edition have been replaced by pictures found in "Identifying_Wood". These are reproduced here at a higher magnification, allowing more detail to be seen. The selection of woods has been altered, with more tropical woods included.
Summing up: although this is a lot more attractive book than the first edition it is only worth replacing that first edition if the book is to be used frequently (for example as a teaching aid). For those who think this is a fairly expensive book I can recommend "The_Good_Wood_Handbook" by Jackson & Day which although much more modest in every respect is good value-for-money, and is a more accessible book.

This book may appear overwhelming to the person who is new to woodworking, and just wants to make a simple project. As you grow deeper in your skills, this book is a must read. It is fascinating for all levels. Hoadley starts off with looking at wood on a cellular level. The different types of wood, have different cell characteristics. If you look at it scientifically, reducing a substance to its cellular level gives you a cross comparative basis, in which to make relational references. Seeming too technically specific for the person, more interested in router techniques, than a science class. But that is just the beginning. He soon goes into the figure in wood, wood identification, water in wood, coping with wood movement, strength of wood, and other properties. He also covers machining wood, joining wood, and finishing wood. Finishing up with modifying wood, the woodworkers raw materials, and Forests past and future.
I would advise someone who is interested in woodworking, to use this book in addition to the others they may have pertaining to woodworking technique. When you get into the building of projects, and see wood "behavior" then this book will all the more make sense. The relationship of how it was sawn and cured, and in what section of the tree it came from, and be relational to why the wood did what it did. It is the easiest to learn that way.
I found it to be a fascinating read. It is like fine art. At first you say, wow that is great. Then as you see it more and more, you come to appreciate the layers of laws that apply to the medium, and gain all the more from it over time.
For example you may marvel at being able to make a perfect fitting mortise and tenon joint, but do you know what the best possible orientation of growth rings in that form of joinery. One way it is apt to split, another way, it will last 100 years. It may not be as much fun as whether Bosch or Makita makes the best router, but inevitably it will result in a long lasting product. It is a fascinating read. Something that should be put on the shelf as a reference source. Read it ahead of time, and read it afterwards to explain, why this thing did that.
Is this the science of wood? Sure it is, but it is done in such a way that, if you don't mind digging through learning the terminology, so you can understand the higher laws of wood joinery and the like, resulting in knowing what may have taken an old master a lifetime to learn. Parts of it are an easy read. Everyone will glean valuable experience from it. It is not so simple that you can have a beginner explain every sentence, but the learning curve is rewarding.
I find Hoadley to be a technician, as opposed to a salesman. Technicians are interested in purely the scientific understanding of the fundamentals, and the relationship of behaviors to bring about the desired result. A salesman is interested in the excitement and appeal of the project, but not the depth from which Hoadley covers the subject. I must admit, that at times it is a dry read. It can best be described by taking a small amount of text from the book. Here is two sections on mortise and tenon joinery. He starts out with this: "Fastening of end grain to side grain joints can be accomplished with a high level of success using mortise and tenon joinery" Later in the same subject he states, "The improvement in mechanical advantage obtained by increasing height is offset by increased dimensional conflict between longitudinal and transverse grain orientation." There you have it. If we knew the terminology that he uses, we could better understand the meaning of the second sentence. What it means is that if you increase the height of the joint, you create a wider surface area, and that creates a stronger joint, but that is offset by the additional expansion and contraction movement in a wider piece of wood. Since the boards in a mortise and tenon joint are typically joined together with grains running against one another, this is a major consideration. We knew that! :-) I had to read that sentence and ponder it before I knew what he meant. At times it reminds me of learing the computer. At times it is frustration, but with understanding, which is a breakthrough, come elation. This book will take you to higher laws and levels.
I guess I am getting wordy. I am excited about this book. As Woodenboat states it on the back cover, "Clearly the best book available on the subject."
I highly recommend you to buy this book. It is an easy read, and it is a complex read, all wrapped up in one book. Each time you reference it, you will derive more and more information from it. It is like fine art. A lifetime of knowledge isn't gained in a single sitting. No matter how many years you spend in woodworking, this book will be right there with you, ever unfolding the true relationship of the product we have come to love; Wood!

I can honestly say that this book is for everyone who works with wood, from the occasional home whittler or handyman to the professional creating engineered lumber.

It covers every aspect of the material, starting with the way a tree's growing environment affects the lumber product. Hoadley gives a variety of different points used in identifying the wood's species. He then discusses the effects of cutting green wood in different ways, drying it (how-to, how long, when it's done, etc), and machining it.

Hoadley doesn't discuss woodworking machines per se, but gives a lot of attention to the interaction of blade and material. He shows the details of how cutting tools affect the visible surface of the wood, and the problems that can come from poor edges, blade angles, pressure, and other factors. He also discusses joining pieces of wood, gluing them, and finishing them.

There is so much here that it's omissions are more noteworthy. It discusses glue joints, but says very little about specific adhesives. That's fair - there are so many, for so many purposes, that the topic deserves an encyclopedia of its own. Also, the adhesives and bonding techniques used commercially are very different from the ones available to home woodworkers or small shops. Any detailed discussion of adhesives would have missed someone's needs. Ditto finishes - the topic is mentioned only briefly. Hoadley's most surprising advice about finishes is the idea of skipping them altogether. He's passionate about the wood itself, and a "least is best" approach shows the material to its best advantage.

With it's profuse and beautiful illustrations, this could be a coffee table book. The information around the pictures is the book's real strength. I find something new in it each time I come back.

//wiredweird

I am just finishing reading the last few chapters of this book. If you are a serious woodworker, hobbyist or professional, this is a book that helps explain the nature of wood and how that impacts the ways we work or should work with wood. The explanations do at times get a little technical, but not anything that should deter someone with basic math skills. Maybe the problem was with myself, but there were a few diagrams and corresponding explanations which left me wondering what the author meant to convey. To elaborate,sharpening was a little bit of a digression for the author, but this is an area where the diagrams and text left me wondering about the details. Regardless, I gave the book 5 stars because of the overall excellent coverage of the subject, achievement of the book's main goal, and I know there are other places where I can get better help, for instance, with joinery and sharpening.

This book is not about woodworking, it is about wood. It is not about the «HOW»s but about the «WHY»s. The author describes wood as a material: how its anatomy and life determine its structure, how the way it is harvested and prepared (dried, riped, planned, etc) will affect its properties, etc. You will learn nothing about the practice of woodworking. Rather, you will acquire background understanding that is essential to anyone who wants to think by himself when working with wood.
The tone of the book is a little bit serious. When reading you will have to pay attention. Included are tables, graphics, diagrams, etc. There are lots of lenghty and tightly packed texts, and the edition I read was illustrated by black and white pictures, wich made for a rather austere appearance.
The treatment of the subject is systematic, torough and intelligent. The acquired knowledge is pertinent and will make the reader a smarter woodworker, one who understand what he does and who appreciate wood as a wonderfull material, one to be thankfull for its beauty and usefulness.

This is THE authoritative look into wood. I have been searching high and low for a book that covers the theory of wood and how it reacts with moisture. Most books throw in basic wood-working information that I don't need, or some "project" samples. This book only had the good stuff: It gets technical, but at an understandable level. It covers the basic cellular level of the tree, on up to how that effects your cut board. Topics include, cell structure, reaction to moisture, how wood dries, how it reacts to changes in moisture, Moisture Content levels to be expected in different regions in the USA, how to store wood, and on and on...

If you're interested in wood and how moisture affects it (and you SHOULD BE!!) than this is THE book.

I'm an electric guitar manufacturer, and recently wanted to learn more about wood. A world-class luthier whom I deeply respect suggested this book, so I bought and studied it.

It fits the bill. It does what you'd want it to do, because it describes clearly how wood grows in tree, how the imperfections develop, and how dimensional changes naturally follow. The writer gives plenty of information about cutting and the marks blades can leave on the wood's surface, as well as how the grains and cutting methods can affect the finishing of the wood. There is also a clear explanation of 'engineered woods' which I found quite helpful.

After reading/studying this book, I have a better grasp of how to select woods, how to focus on the differing properties of different kinds of hardwood and softwood, how to better cut and finish the guitars I make, and quite a bit more.

My luthier friend said that this was *the book*. I think he was correct. Perhaps you might find it so as well.

Hoadley's Understanding Wood provides an excellent if somewhat technical overview of the properties of wood. It's written with woodworkers in mind. Beginning with an anatomical view of the parts of a tree, the author gives a cogent summary of the functioning of a tree as a system. This is not easy reading, but it's worth the effort. Almost everything in the remainder of the book has some relevance to woodworking whether it's his essay on knots and why they behave the way they do (Chapter: Figure in Wood) or understanding tear out (Chapter: Strength of Wood) or the ultimate questions of moisture content (Chapter: Water and Wood) and wood movement. But beware, although the author is a woodworker himself, he's also a professor of Building Materials and Wood Technology at the University of Massachusetts, and he's not writing for "dummies". Wading through the technicalities of the first chapter's anatomical study will bear fruit (or maybe nuts?) when dipping into the later, more practical chapters. In those he presumes your understanding of wood's structure. The book is well-illustrated with color photos throughout, although there are times that you wish you had the actual piece of wood in your hand. Highly recommended for motivated learners!

This book covers a tremendous amount of information that the general woodworker needs to know but would likely take 20 years to learn on his own. So why isn't it sold in my local wood working specialty store? Because it has a weak first chapter that can be confusing and slightly incomplete. Other parts of the book are better written. Don't let the first chapter scare you off just keep reading, it gets much better and quite thrilling at times. By the time you finish you will feel as though you've taken a college level overview course on woodworking. The information gets deep but is decently written for the non-engineer most of the time. I feel lucky to have found this book.

This book had a lot of information that I personally didn't need, but lacked some that I wanted. Most noteably wood identification. It presents an entire section on this topic, but only shows microscopic views of different species, which is pretty useless to me. The author assumes that if you're reading this book, you can look at almost any piece of wood an identify it, thus making a pictorial directory of wood almost beneath the sofistication of this text.

It is a well written book if you want to understand the science of wood. Think of it as an anatomy & physiology for wood. I would have given it a 5, but ommitting normal pictures of wood types seems to easy to have been left out.

I would consider myself new to woodworking, but not a complete novice. I have read a few books about the principles of woodworking, and all of them contained very little information about the nature of wood. These books left me with many questions about why certain methods are used or when to use one method over another. Understanding Wood answered a lot of my questions. Most importantly I now understand how to take into consideration the nature of wood when I am planning a project. The most important thing that I learned in this book was about the importance of moisture content. Sure I knew that wood expands or contracts with humidity levels, but now I know how to plan for it and work with it and I also know how detrimental it can be if you don't consider the relationship between water and wood.

What I really liked about the book is that the author did not pull any punches in his exposition meaning that this is not written for someone who prefers a "for dummies" book. This is the real deal, it contains some equations, it has many tables and graphs. Don't be too intimidated though, because it is not as dense or dry as a standard textbook. I think for anyone who enjoys woodworking this would be a great read.

My only complaint is that I wish the author could've gone into more detail on a lot of the subjects. He often wrote that a detailed discussion would fill a whole other book or even volumes. The problem is he's right, so the trade off is that some information is left out since the book can't be thousands of pages long.

As a professional Wood Scientist, I wholeheartedly recommend this updated and readable college textboox. This book is used for introductory classes in wood identification and the understanding of wood properties. This excellent and well organised book covers wood identification by 10x hand lense, and microscopic identification of softwoods, domestic and exotic hardwoods. Colored side by side photos are a tremendous help in the keying out of similar looking species. Woodworkers will greatly benefit from this inexpensive yet comprehensive book. For my oral exam in graduate school, I was advised to memorize this book and neglect all others. The advice was good! I passed. If you only buy one book on wood, you must buy this one!

I have been a woodworker for 25 years, through trial and error, and alot of mistakes, I have learned much. After reading this book, "Understanding Wood" I understand even more now, why furniture reacts the way it does. Any one interested in becoming better at woodworking should read this book. It is quite technical at first, but then different things start to make sense. Why did that panel split, why did I have a gap a year later. I urge you to read this book, at what ever level you are. Thank you, Mr.Hoadley.

This book takes the reader beyond the basic understanding of wood. If you are interested in a deeper look at wood as an engineering material or if you are more than a weekend woodworker, this book fills a big gap between the pure scientific and craftsman levels. Well written and great illustrations.

This book gives a great account of all the properties of wood and even shows why different woods are better for different applications.

I was able to select the best wood for an application in which I was using wood for a bearing surface.

This is a great book.

Great book. As a beginner in woodworking I was frustrated with some of the results I got on some projects. I now better understand what is going on. The book is over my head in more than one area, but as my experience grows, I think I'll understand even more.