In this article we will talk about what are checks and what are cracks in lumber and turning blocks. What causes wood to check and crack and what can be done to stop or slow down the process.
A check is a small crack that occurs in the end grain of board or log. These checks can increase in size to form a crack. A crack is usually a grain separation within the wood fiber. Any piece of timber will check as it dries. This is a natural occurrence but varies between tree species. All will check; some more and some less.
Beginning with a piece green of timber, (green wood is wet wood) the surface begins to dry; as wood dries it shrinks; the wood fiber on the outside of the timber dries at different rate than the inside wood. As the moisture evaporates from the wood, the outside faster and the inside slower, the exterior wood shrinks, around the interior wood which is wetter and is larger; so the exterior will check as it contracts around the wetter center wood. Left alone these small checks will continue to grow and will render the wood worthless or firewood.
There are several methods to prevent or slow down the checks. In order to do you have to slow the evaporation process down. One way is to coat the ends of the timber with wax (Anchor Seal is good) this will help but not in all species. The local environment has a lot to do with the drying of the wood? Do you live in cool moist area or live in hot dry location.
The timber can be cut into various sizes for future use and then stacked in a cool dry location with good air circulation. There will be some checking and cracking with this method but usually you can work around them. This type of drying takes longer and requires more room.
The best way to dry wood is to use a kiln. This can be expensive but the recovery of wood from the loss due to checking and cracking is large, and the time required to have dry wood ready to use for you project is a huge benefit. On a small scale the kilns are easy to build. They require an insulated box of some size, fan for air circulation, a heat source and dehumidifier to remove the moisture.
I recently built a small kiln in which I could dry 5 to 6 bowls that I turned from green wood. Most of the bowls take 7 to 10 days in the kiln and I usually place them in dry place and let them acclimate for about a week. A couple of tech tips. If the dehumidifier removes the moisture to fast the wood will crack, use an off and on timer. The moisture meters won’t work. Weigh the wood each day, as the wood becomes dryer the change in weight will slow down. When the weight changes slightly from day to day or ceases to change, the wood is dry. There will always be some amount of warping, so over cut the wood so be able to remove the warp.
I always like to turn green wood. The small kiln works very well for me. I wrote a blog on how to build one on these. Check it out.
http://blog.yourwoodturningtools.com/2016/10/a-simple-kiln.html
End Grain Checks, Green Wood, Kiln, DehumidifierSegmented Bowl
I’ve been planning to turn a segmented bowl with using several species of wood glued together to form a pattern as one of your many projects, here are a few tips and hints on doing just that. If you’re serious about your woodworking hobby, then you’ve probably goggled the subject and seen images of all the amazing things.A Turning Project
If you’ve been planning on experimenting with using several species of wood glued together to form a pattern as one of your many projects, here are a few tips and hints on doing just that. If you’re serious about your woodworking hobby, then you’ve probably Googled the subject and seen images of all of the amazing things that other people who love to craft stuff from wood have made using this particular woodworking method. Some of them are quite amazing and your project can be, too!Turning A Wooden Mallet
A mallet is one of the small items that virtually every person or family needs. However, not many people realize that they need a mallet until there’s some work that needs to be done and it is required.