Question:
How can I prevent my timber from splitting open? We manufacture furniture in South Africa – Cape Town – then transport it to the country as soon as it is delivered. A month after that, our turned legs craps open. We use a glue called Balcotan 100 which is the best glue here in Cape Town. What can we do to prevent it from happening?
Submitted by Clinton
Answer:
Having spent time in Africa (I lived in Swaziland for three years), you have a humidity problem. The humidity at the Cape is high. If your products go up toward Jo-Burg or Pretoria, the humidity is lower, and the wood reacts. It’s hard to overcome wood movement. If it wants to move, it’s going to move. You’d have to deal with this by controlling the environment where you’re manufacturing the furniture. Can you lower the humidity in that environment to match the humidity where the product is ending up?
- George
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I am a woodworker and had built my house too in later years. I used to cut cord wood for folks but found some of the maple so goo that I used them for carving(lures) and furniture making. To best keep wood from splitting seal the ends with epoxy for at least 6-12 months before using and hardwood should be quarter sawed too. Least amount of curly bends in grain of woods. I also play guitar so keeping moisture in roo(6%) keeps from the wood cracking - same with too much humidity -dehumidifier!i
You may also want to ensure that the pieces of lumber you're turning for the legs doesn't include the pith (the center of the tree or branch). I only mention this because the nature of your comment makes me think you might be turning relatively green lumber.
Extra details might help to determine the exact reason for the problem. What type of wood are you using? is it an "oily" wood? does the grain of all the components run in the same direction before glue up? Are all the glue up components cut from the same board. Humidity will be a big factor especially if you are supplying into the Karoo area and manufacturing in winter. (Rain.) It seems that the main issue is the turned legs so perhaps these factors listed could assist with solving your issue.
I own a sawmill in east Texas. We have high humidity. I paint the ends of the logs with a thick coat so the wood dries without passing through the ends. I also let it dry to the proscribed moisture level using a detector. I do not use any moist wood in my projects. Yes, sometimes checking occurs (ends splitting) but this method has served me well. Jim
I paint the end grain, since this dry faster than the rest of the log. That way the log will dry evenly and help prevent the wood from splitting.
I am surprised there was only one comment and it was not germane to the question at hand. It seems to me that the wood has to be dried to a moisture content compatible with the environment it will eventually live before fabrication and in a shop with compatible humidity controls.
TWO COMMENTS: I just watched the video with Tom and his knives. George mentioned in that video that he would like to forge his own damascus blade. There is a great video on CarterCutlery.com on forging damascus knives. Note the handle making techniques as well. Secondly, I was watching the video on turning the large butternut bowl. One critical aspect is how to mount such a piece of wood on the head stock. What was used and how was it done?