Understanding Wood Movement

 

In this lesson, you will put everything you’ve learned to this point to work understanding how wood moves. The concept of wood movement affects everything we do as woodworkers, so it’s important we understand how and when wood moves, how much, and what the rules are. We also learn how to recognize in what situations the movement of wood will cause a joinery issue. It is strongly recommended that you do the required reading prior to watching the video…

Associated Reading:  Understanding Wood, Chapter 6   :  Modern Cabinetmaking, Pages 189-190


Video length: 20 min, 20 sec

Introduction to Wood Theory


What makes a high quality woodworking project? There are, of course, many answers to this question. One obvious answer is that the craftsperson must have the necessary joinery and tool skills and attention to detail needed to create a top notch piece. The less obvious answer is that he or she also needs to have a deep understanding of the materials needed to build the project; in this case, wood (also called lumber).

Wood is unlike other materials, such as metal, in that it shrinks and expands due to humidity in the air, sometimes significantly and it does this throughout it’s entire life. While it’s possible to build projects without the knowledge of how wood moves and reacts over time, this can be a recipe for disaster in that over time the joinery can fail due the failure to consider wood movement when designing and building a project. The most skilled woodworkers fully understand the properties of wood and how to design joinery to accommodate that movement. When designed and built properly, there’s no reason your projects can’t last for generations.

The good news is that woodworkers have understood the properties of wood for thousands of years and have developed many techniques to accommodate wood movement, so no need to re-invent the wheel. The best part is that you don’t need to memorize hundreds of joinery options. Once you understand a few simple rules regarding wood movement, you will easily recognize problematic situations allowing you to research the best way to solve the problem.


Preparation

Peter Korn said it best in his book, “Why We Make Things and Why it Matters – The Education of a Craftsman

“In furniture (and cabinet) making, beginnings are critical.  For a simple frame-and-panel door to stay flat over the long haul and not become too tight in summer or overly gapped in winter, success starts with the choice of timber.  Not just what species or which plank, but also from which part of the board one saws the stiles and rails, how dry the wood is, the method by which it was dried, and how it was stored and handled.  All this before the actual work of milling the timber flat and square, laying out and cutting the joinery, making and fitting the panel, assembling, trimming, fitting, hinging, latching, and finishing.  

Throughout the entire process, the quality achievable at each stage is utterly dependent on the care with which the craftsman has accomplished every previous step of the way.”  

Peter Korn, longtime woodworking educator and furniture maker


The last quote is particularly important; when building anything, every step matters and problems can cascade if care is not taken at each stage. In our case, it all starts with wood and it’s preparation, so let’s dive in…


Some notes about the course: Each lesson consists of outside reading from Understanding Wood and/or Modern Cabinetmaking, a video, and a quiz. You must progress through each lesson in order and pass the quiz before moving on; you may take each quiz up to three times to obtain a passing grade of 80%. It is strongly recommended to do the outside reading before watching the videos.

Lumber Measurement and Grading

In our last lesson, you will learn how lumber is graded, measured, and sold. It is strongly recommended that you do the required reading prior to watching the video…

Associated Reading: Modern Cabinetmaking, Pages 205 – 210


Video length: 20 min, 6 sec

 

Coping With Wood Movement

Now that we understand the mechanism of wood movement, when it moves, and how much, this lesson will explore how we use this knowledge to recognize when we have a wood movement issue, and more importantly, how we cope with the movement. Once you understand this, it’ll be easy for you to create strong, long lasting woodworking projects that will last a very long time. It is strongly recommended that you do the required reading prior to watching the video…

Before diving into how we cope with wood movement, please watch the first video to review some of the concepts in the previous lessons…

Associated Reading:  Understanding Wood, Chapter 7


Video length: 16 min, 0 sec


Video length: 27 min, 32 sec

 

 

Moisture and Wood

 

In this lesson, we will start to explore how moisture works in wood; how it gains and loses moisture in relation to environmental humidity. We also begin to explore how and why wood is dried before we use it. This is a very important and fundamental lesson to understand as it sets the stage for the remaining lessons in this course. It is strongly recommended that you do the required reading prior to watching the video…

Handouts: You can view and/or download several important handouts by clicking on the Materials tab above; scroll down to see all of the handouts.

Associated Reading:  Understanding Wood, Chapter 6   :  Modern Cabinetmaking, Pages 186, 198-200,


Video length: 26 min, 44 sec

 

Figure in Wood

 

In this lesson, you will gain a deeper understanding of wood including grain and figure, methods of sawing, and various other properties of wood. It is strongly recommended that you do the required reading prior to watching the video…

Associated Reading:  Understanding Wood, Chapter 2   :  Modern Cabinetmaking, Pages 185-186, 190-191, 196-198, 200-201


Video length: 26 min, 43 sec

Nature of Wood

 

In this first lesson, you will learn about the basic anatomy, structure, and classification of trees as well as a brief discussion of wood density. It is strongly recommended that you do the required reading prior to watching the video…

Associated Reading:  Understanding Wood, Chapter 1   :  Modern Cabinetmaking, Pages 181-185


Video length: 11 min, 44 sec