Saturday, July 4, 2009

Woodworking with a piece of raw tree trunk

My friend recently had a tree die and fall over on his property. He cut it up with a chainsaw, and offered a few of the pieces to me for use in woodworking. I have never started a project with just a raw log, so I figured it would be a fun learning experience. The tree died in the winter, and it was soaked with rain water, so I put the pieces on a few bricks to keep it off the ground and covered it with plastic on rainy days, leaving it uncovered on dry days. After the rainy season was over, I removed the plastic, and left it sitting in the sun for few months. It's dry now, but badly cracked. I have a feeling it may have been cracked even before the tree even fell over, but I would be interested in hearing from anyone who has experience drying logs.

I chose one of the smaller logs and sliced off a piece with the bandsaw.

Next, I clamped a 4x4 to the bandsaw table to act as a crude fence. It's set to a little over 1" of thickness from the blade.

I jointed the exposed log face before cutting each 1" slice with the bandsaw. I then jointed the other side of each board, and also jointed one edge. I then planed each board to exactly 1" and used a table saw to square up the other side. I now have flat, square stock ready for the project. The wood had lots of cracks, but the figure was really pretty. I think this was an almond tree.

I ended up cutting the boards into 1"x1" x 12" long strips. I decided to make a napkin holder, since it was something that I could build with a small amount of wood, and would be useful. I used standard yellow wood glue and only used tape while drying -- no clamps.

I used a 1/8" radius round-over bit in my router table to smooth the edges, then sanded with 150 grit on a random orbital sander, and also did some hand sanding. I applied a Tung oil finish (my favorite finish) in a few heavily-rubbed coats.


  1. The cracking is caused by rapid drying. Wood end grain is like a pack of straws. When you don't seal the ends the moisture drains out too quickly causing the cracking you see. The best sealant is probably wax, latex paint is also used but many say it doesn't work as well..

  2. Thanks for the note about sealing the log ends. I will give this a try next time.

  3. Yeah...this is not so relevant now is it, but I persevere. I'm no expert but in my experience mostly in American hardwoods, not to be confused with hard woods, cracking can and will occur if the pith of the "green" (a term for freshly cut lumber; contains high percentage of water) log is not removed due to increasing tension between the plant cells as the amount of water decreases from within the cells; the wood shrinks. This shrinking normally causes radial cracks known as checks but they may also be known as stars which I saw in an old book, but I'm still unsure of that. On a semi-unrelated note, considering that the amount of lignin determines the hardness of the wood, I have a theory that a harder wood will get many, smaller cracks because the lignin tends to hold the plant cells together more effectively and softer wood will get fewer, larger cracks excluding softwoods (pine, etc.) because there is less lignin to keep the wood from cracking (this theory only applies cut lumber and not a solid log). But I digress, another explanation for why I believe wood cracks is that the wood has contradicting ring growth, let me explain. The normal growth of a ring is usually in a concentric circle pattern which I'm sure most people are aware of, but if a tree experienced a time where the pattern was broken and the ring grew in a mirror image (picture a crossectional area of a tree; aka the endgrain) of previously rings, then when the lumber dries, regardless of whether the pith was removed or not, there is exceptionally more tension in the location of that odd growth. This explanation more commonly occurs in very hard exotic hardwoods. If you're still reading this then I have to say that this observed effect brings up many issues to me about the behavior and interactions of the individual grains of the wood, the parts of wood that are commonly described as a bundle of straws, or strands of spaghetti. Now that being said, I do not believe that the rapid drying (to an extent) has a large effect on this internal stress leading to cracking which is most likely going to occur eventually during the drying period of the log, but rapid drying in the form of extreme heat may have a larger effect. Whooffff... that feels to get off of my chest.

  4. ...feels GREAT to get off of my chest. And I'm to tired to write anymore right,

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