Understanding Wood: 7 Things You Must KnowBefore You Build Your Next Project
Ask yourself these questions. How in the world can we build things from scratch without knowing anything about wood? How can we expect to get good result if we don’t understand the fundamentals of wood? If you want your project to be something your proud of, you must understand the wood before you attempt to build with it, and especially before you go to finish it. Otherwise you’ll find yourself wasting time and money, and another trip to the lumberyard for more wood. Once you have a better understanding of the wood you are working with you have a better chance of your projects turning out to be a success.
#1 Wood Is Constantly Moving
You know the infamous tip that you should let wood flooring acclimate to your room by leaving it there for a few days before installing it. Wouldn’t it make sense than to say if your building something, the wood you plan to use should have time to acclimate in the room you’ll be using it before you start cutting and screwing it together? Yes! I’m sure you’ve heard of people moving from one part of the country to another part of the country and find that the veneer on their furniture is chipping and cracking, maybe even falling off. See where we’re going with this? It’s the same thing if your building down in your basement where its moist. When you finished, you bring it up to its new spot somewhere it the house where it’s dry, and sitting in direct sunlight. Then you notice the boards start shrinking and cracking. This happens because on part of the country (or house) may be more humid then the other part and wood reacts differently in different environments, and different parts of the house.
Wood changes due to the expanding and shrinking of its fibers due to moisture. Keep in mind though wood doesn’t change in LENGTH. It does change in WIDTH, in some wood more so than others.
2: You Must Consider The End Grain
Look at the 3 picture of wood below. The first one is plain sawn (also known as flat sawn.) This type of board shrinks more than the others, which could be a big uh-oh for your projects if you don’t know this. The second one is called rift sawn. This board is pretty stable and won’t shrink as much. This is the preferred type of board that people build with. The last board is called quarter sawn which can also be pretty stable.
What does the different end grain tell us? It shows us that the wood was cut from the tree in one of three different ways. Depending on how it was cut, the board will shrink in a certain way. Remember this:
· Plain sawn (or flat sawn) boards are known to shrink more and bow unevenly, and you can see more of the rings of the wood.
· Quarter sawn board shrink only half as much as plain sawn and will not bow and cup since it shrinks evenly. You’ll also see straighter grain and may even see ray lines that look like stretch marks along the board.
These three kinds of woods are each good for certain types of use depending on how it reacts to the environment it is used in.
#3 Barometric – Know it!!
Yes, we know you are woodworkers not a meteorologist, but you know how on the back of a paint can it always tells you to only use in “x” temperature. Well the same goes with wood and the barometric pressure. You should NOT be cutting, gluing and definitely not adding finish to projects on days when the barometric pressure is changing too much.
When the barometric pressure is HIGH you’ll notice nice cloudless days. When its LOW, you see the clouds and rain. Why does this matter? Sudden changes in the barometric pressure affects the amount of moisture in the air, which means that if you try to add finish on a day that suddenly has a low barometric pressure, your finish will trap the moisture and become cloudy itself.
If your cutting boards with a low barometric pressure, and then the pressure suddenly rises, your boards may end up being the correct dimension because the increase in pressure caused them, to shrink.
#4- KNOW THY WOOD
Aside from knowing if the wood you are using is plain sawn, rift sawn or quarter sawn, it is important to know the characteristics of the wood you are using, Before you go to purchase your wood, look up what you plan to use on the wood database site, (http://www.wood-database.com) and read about its characteristics. This way you’re not wasting money, and know for sure if the wood you are planning to use is suitable for your project.
#5 Don’t Build Something In One Place and Then Move It To Another
We know this can be easier said than done. There’s reason you just turned your garage into your nice new workplace. But like we mentioned earlier wood acclimates to its environment. It’s best to let it acclimate where you plan to have it when it’s finished to avoid it from falling apart.
#6 Check the Moisture Level Of The Wood
See this neat little tool picture to the left, this is going to be your best friend when it comes to woodworking tools. It’s the Moisture Meter (MLCS item#9137). It measures the exact moisture level of your wood so you can make sure the moisture content of the wood you are working with is stable enough before you go to use it.
#7 Pre-stain Wood Conditioner – Know When You Need It!
Wood conditioner before staining woods that are soft and porous (such as pine, poplar, maple, fir, alder, aspen, and birch) is a must. It seals up your wood to help ensure an even less blotchy finish. This will be a game changer for some of your projects!
Keep these 7 tips in mind the next time you go to start a project, and we promise you, your finished project, will be worth the extra minutes you took to know your wood!