Coping with wood movement
All wood workers need to be aware of wood movement when building furniture projects. Failure to consider this important factor can cause wood panels to crack or split.
My high school biology teacher compared the structure of a piece of wood with a bundle of straws. The straws represent the cells and capillaries of the wood. When a tree is growing water and food are transferred up through the cells and are carried throughout the tree.
Once a tree is fell the free water in the wood is lost rather quickly but the bound water trapped in the straw like cell is slower to dissipate. As the level of bound water is reduced these straw like cells get narrower in diameter but maintain their length. This is the fundamental reason that wood expands and contracts across its width but has almost no expansion length wise.
When working with wood it is very important to allow the wood to expand and contract with changes in humidity. As humidity rises the straw like cells expand in diameter with the opposite effect occurring as the relative humidity falls.
Ways to accommodate expansion
Lets use a cutting board for the first example. A solid wood cutting board with a bread board edge secured with a tongue and groove joint. One edge has the bread board edge secured on both ends with a dowel through the tongue The other bread board edge is secured with the same tongue and groove joint but this end only has a dowel in the center of the piece.
The end secured with two dowels will develop a crack in the main panel. Since the length of the edge piece doesn't change having it fixed across the width of the main panel from expanding.
Alternatively, the opposite end of the cutting board is only fixed in the center. The main panel is free to expand and contract towards the ends. The only visual difference would be that the ends of the edge piece are no longer flush with the edge of the main panel.
The second example uses a large glued up panel such as a table top. If the table top was fixed to the rails across the width of the panel the rise and fall of humidity would undoudtable cause the panel to split.
The best method to overcome this is use wooden clip to attach the two pieces. A 1/4" x 1/4" dado milled on the inside upper edge of the rails. This accepts a wooden clip that fits into the dado and is then secures to the underside of the table top. This will security hold the top hold the top onto the rails without restricting the expansion and contraction of the large panel. Without this the table top would slowly start to open up.
In general anytime you are fixing one piece of stock across a large glued up panel measures need to be taken to allow the panel to move. Remember that it will expand across its width but not its length. Using one of the two methods mentioned above you will be able to prevent your glued up panels from splitting.
About The Author
Dave Markel is the author of "The All Wood Working Journal". He has helped hundreds of individuals improve their wood working skills. Visit his site at http://all-wood-working-plans.com. Subscribe to the All Wood Working Journal at http://all-wood-working-plans.com/wood-working-tips.html.
Purchasing a hot tub is a big investment and one... Read More
In this article, we'll be taking a look at the... Read More
If you burn gas, kerosene, or wood in your home... Read More
Interior Design today is all about customizing your built environment... Read More
You're all comfortable in your favorite lounge chair, reading your... Read More
Hand hooked rugs are a great way to add splendor... Read More
A wet basement can be just a nuisance or even... Read More
When the wife comes to you one fine day and... Read More
Commercial steel buildings are prefabricated and custom-designed for use as... Read More
Circuit Breakers are devices that stop the electrical current of... Read More
According to the National Association of Waterproofing and Structural Repair... Read More
The Holy Grail of distributed audio; unlimited zones and unlimited... Read More
Is your bathroom looking cluttered? How about fitting new bathroom... Read More
Building a set of wood stairs is not nearly as... Read More
Last week I told you how to measure for your... Read More
While remodeling your kitchen, install only the essential cabinets, so... Read More
Want to improve the look of your property? Want to... Read More
Are you frustrated with the high prices you've been quoted... Read More
Most of us enjoy daydreaming about our perfect home. Do... Read More
If the decision of what type radiant heating system to... Read More
How often you have used tools for your everyday living?... Read More
Did you know that over 50% of women now run... Read More
MISTAKES.Don't worry about making mistakes. Everyone makes mistakes. Why should... Read More
When you think about an above ground pool do you... Read More
If the sliding glass doors in your home are more... Read More
Before getting your house valuated think about the list below... Read More
Is it time to give that tired kitchen floor a... Read More
Do you have any idea how popular outdoor kitchens are... Read More
Buying a home is usually a stressful experience. So much... Read More
Window coverings serve an important role in your home, giving... Read More
For the past few weeks, I have been explaining how... Read More
Here are five important things to remember.1. Use a steel... Read More
The installation of a new bathroom vanity and countertop can... Read More
Many Florida residents that have come from the North are... Read More
Probably the most common type of residential extension is the... Read More
A well-decorated room can still lack personality. To give your... Read More
Moving households, whether it is due to a job transfer... Read More
While you are cleaning leaves out of your home's gutters,... Read More
Has your house had a check up yet?Home inspection is... Read More
Interior design for couples is one of the hottest, most... Read More
When decorating or making decorating decisions for new homes, it... Read More
Your choice of bathroom cabinet can affect the look and... Read More
Fans extending from the ceiling have been around for centuries... Read More
Few things can be as frustrating as picture problems. You... Read More
We get a great many requests to view the potential... Read More
A bathroom vanity is the centerpiece of your bathroom. Regardless... Read More
It's now well into the new year and the residential... Read More
There is a perception amongst most folk that every house... Read More
One of the advantages of using machines to control processes... Read More
The Holy Grail of distributed audio; unlimited zones and unlimited... Read More
Triple scented, heavily scented, strongly scented - these are all... Read More
A ceiling fan consists of three basic parts, namely the... Read More
No one wants to have their house equipment broken. But... Read More
You have found an apartment you like and you are... Read More
For Paint Manufacturers worldwide, there has come a radical new... Read More
If you wish to learn how to manage interior design... Read More
It is important to be a very careful consumer when... Read More
Hello, my name is John Rocco.I grew up around the... Read More
The health benefits of saunas are not a recent discovery.... Read More
Careful planning is the key to a successful bathroom-remodeling project.... Read More
A miter saw, also known as a "chop saw," is... Read More
Steel is gaining in popularity as a building material due... Read More
When you add up all the money that you can... Read More
The installation of a new bathroom vanity and countertop can... Read More
These days, finding advice or guides to interior design is... Read More
Quick: What comes to mind when you think of soy... Read More
Home Improvement |