Sunday, March 25, 2012

To Make a Single Ox Yoke, Part 4

Preparing the Wood for Carving



Yep --- that's my granddaughter! Much credit goes to her dad for finding and delivering the log to me. He is a professional tree trimmer by trade.


What I'm starting with is a North American Ash.(Green or White, I'm not sure which.) It is a short-log that was cut out of the center of a longer log. The longer log had cured for two-years at the time the picture above was taken.


After cutting it into the shorter piece it cured another 6-months. Contrasting the picture above with the one below shows that significant radial cracks have formed on the ends during that period of time.

There is some insect tracking in the wood, but that seems to be contained mostly on one side.  I should be able to get at least one good ox-yoke out of the log.

(The log is not infested with the Emerald Ash Borer. There are native species of insects that also bore in Ash wood. If you are considering using Ash be sure to google the Emerald Ash Borer  for your state or province, and educate yourself. It is an invasive species and can spread in firewood or logs. It has decimated  North American Ash, i.e. White, Green and Black, in some areas, and threatens to do so across the country.)

After trimming about six inches off the top the cracks were removed.


I want a rectangular box shaped block of wood from which to start carving my ox yoke. Having the parallel planes of the rectangular box to work from, will give me clearly defined reference points.

I will cut the log with a chainsaw. My first step is to put on a brand new saw chain to help keep the cuts as straight as possible.

I have nailed a board to the side of the log to act as a visual guide while sawing.

The right-angle (edge) of the board helps me to keep the cut square with the log.

So as not to dull my saw chain on the nails of the pallet, I left the last inch or so of the log uncut, and split it the rest of the way with the iron bar.

Opening up the log gives a better view of the quality of the wood.

The darker wood down the center is the heartwood and is less desirable for carving than the lighter colored sapwood. 

The left end of the log is already squared. (Scout the Ox and Harry the Dog are keeping watch in the background.)

I am squaring the right end, averaging by eye what square is on an irregular log.

I now have two ends at right angles to the large flat side --- or first face.

Using a carpenter's square I have marked out my center-lines and the other three sides of the rectangular end. Two of the corners will be rounded allowing me to get a larger portion of the best wood into the center of the yoke.

Again, measuring and nailing boards as guides for the saw.

The boards have to be parallel up and down and also representative of the plane of the first face.
The chainsaw didn't do perfect work --- so I have to eyeball the average of the plane. I have used a shim to make a correction.

I start the cut on the line I have drawn on the end of the log. 

And use the edge of the two-by-fours as a visual guide, to keep the cutting blade at a right angle all the way through the entire cut from top to bottom.

You can see by the guide-board on the right, how it is square with the heartwood and the newly cut edge on the left, but not square with the edge of the tree (which was wider at the bottom than at the top). My next cut along the edge of the second guide-board will make the face of the block facing the camera into a squared rectangle.


With the four edges of the block at right angles to the first face-cut, it's now fairly simple to align the guide-boards with the lines drawn on the top of the log, and to measure thickness top and bottom, from the first face-cut to the guide-boards, to get the block equally thick on both ends after the next, and last, cut.

After checking everything I nail the guides in place.

You can see I made a small correction again with a shim (wooden wedge)at the top left corner.

The cut is nearly completed.

A first look at the second face of the block.

We now have a block of wood that is nearly the shape of a rectangular box (right cuboid).


Up next --- transferring the cardboard patterns onto the block.
Posted by Picasa