Friday, June 5, 2015

Chair Build Day 1

Well as you might imagine getting around in the shop with a large medical boot brace on ones foot is cumbersome.  However, I must press on.  Usually I would split, rive and shave my arm and bow parts first. Followed by a good steaming then bending them in their appropriate forms and setting them aside to dry.  Then I would move onto the other greenwood work, the spindles.  But as I said in a previous post I am going to be doing things a bit out of order, due to my aforementioned state of gimpiness.  I am attempting to recruit a strong young person to split that big ole oak log for me.  So far no luck.

So I started on the seat blank.  I laid it out, drilled my center spindle hole and the four leg holes.  I then began to carve the bowl of the seat.  I am happy to report that the Sugar Pine carves very nicely. Like its cousin Eastern White Pine it requires sharp tools.  I started with my adze made by Tim Manney.  It works so nicely and made very short work of removing the bulk of the seat bowl.  I am a novice with this type of adze and am still learning the nuances of the tool.  Next I moved onto the scorp/inshave. Taking a skewed cut working downhill while paying close attention to the grain is paramount.  The wood will let you know how it wants to be carved.  It is very important to heed its warnings so as to avoid tearing out a deep hole that will be difficult to remove.  The last step was to move to my travisher made by Claire Minihan.  The travisher is a bit of a peculiar tool to learn to use, for me at least it felt a bit counter intuitive.  Again I used a skewed cut working downhill paying attention to what the wood would allow me to do.  Using my bandsaw I cut out the front of the seat in preparation to carve it.

Tools Left to Right: Adze, Travisher, Scorp/Inshave

Next I drilled the arm post holes.  To do this I used a square, bevel square and mirror to obtain my 17 degree angle along the sight line.  The mirror allows me to compare my drill bit to the bevel square with a glance rather than having to move my head around causing me to loose alignment with the sight line. I use a square lined up perpendicular to the sightline to help me stay aligned as close as possible to the sightline.

After drilling both arm post holes I turned the bamboo style arm posts on the lathe.  I do this before reaming because I want to assign and fit an arm post to a particular mortise during the reaming process.  The arm post will be marked for its particular mortise and that is where it will reside for the remainder of its days.

Bamboo Style Arm Post
Next I ream the arm post holes and make them into tapered mortises.  As when drilling, I use a square, bevel square and mirror when reaming.  My reamer has a 6 degree included angle, therefore I set the angle to 14 degrees, three degrees less than the 17 degrees used to drill the holes.  I align the blade of the square with the sightline and compare the top tip of the reamer with the blade of the square.  If it lines up with the edge of the blade, I'm spot on.  If the tip is left I must take more off the right side of the mortise and vise versa if the tip is right.

Reamer is in line with the sightline
Next I brought the bevel square up to the reamer and observed the gap between the blade of the bevel square and the tapered surface of the reamer.  If the gap is the same up and down the reamer, I'm spot on.  If the gap is larger at the top I need to take more off the mortise toward the square and vise versa if the gap is larger at the bottom.

Reamer is at the correct angle

So after reaming both mortises to the indicated correct angles one might think that it is a completed task.  Oh contraire!  What I have neglected to explain is that I actually don't ream the mortises to their final depth until after I check to see that both arm posts are in the same plane.  I feel this is one of the most critical stages of building an armchair.  If the arm posts are not in the same plane it will make it hard to get the arm to sit correctly at a later stage in the process.

Winding Sticks to check the plane of the arm posts

Even though everything appeared to be correct, a pair of winding sticks would let me know just how close or far off  I was.  At first check I was off a wee bit and it was close enough that a very minor adjustment, a half turn of the reamer to the left arm post mortise, was all it took to be nuts on.

The gap at the left is ever so slightly larger than at the right.  When the gap is even everything is copasetic.
Well that was all my foot could handle for the day.  Next I will be turning the legs and stretchers for the undercarriage.  All the while I will be attempting to recruit some help with getting that oak split.  

~ Ray Schwanenberger

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