Let’s start with a confession. I did stuff around with some of the photos in this post. It is the first time that any of JNSQ’s photos have been altered, as far as I can remember anyway.
The previous posts in this series can be found here.
In this edition we will take a look at some of the joinery and the first phase of preparation of the top for finishing.
The first bit of joinery I attempted was to fit a small block to the top of each leg construction. It will be the point that fix the centre of the leg to the centre of the top. All the other connection points will allow for wood movement, but these two will not. This means that the top will be able to move freely with changes in humidity, but the centre will remain fix to the centre of the legs. I think this is called a T-bridle joint. One feature of my Langdon mitre box and saw that came in handy here was it’s ability to set the depth of cut. Obviously you can simply do this by hand, which would also be much quicker. Where the mitre box might have an advantage is when you need to do heaps of these joints with the same dimensions. In this case it was an opportunity to work out how to set the mitre box for a job like this. That way it will be easier next time.
A router plane works well for the cheeks of the bridal section. It was a bit of a challenge to hold such a small piece while cutting the cheeks to depth. The solution was two dogs and a Veritas gadget. That could be a good name for a progressive rock band or a retrogressive gin mill (Two dogs and a Veritas gadget), come to think of it.
Next up were the slots in the top of the legs.
The two aprons are also jointed to the legs by means of T-bridal joints. Here I am marking the exact location of the shoulders using the leg.
That was followed by the same sequence involving the mitre box, router plane and careful chisel work to perfect the shoulders.
So then on a crisp and bright winter’s Friday morning I started to flatten the bottom side of the top. Seeing that it is the first table top of this size in Kershout that I am doing by hand I thought that the bottom side would provide an ideal opportunity to work out which method works best. The major challenges posed by this top are the schizophrenogenic nature of grain and the extreme hardness of the wood. As every self-respecting JNSQ Woodworking reader should know by now, we deal almost exclusively with feral boards from the ancient Knysna forest. Each of the trees that the boards for this top were sawn from would have been over 500 years old.
If you deal with wood like that it is my opinion that one has a real responsibility to do the best possible job of allowing the story of the tree to be told. In my estimation that means a delicate balance between careful surface preparation and leaving certain imperfections that relates to the history of the piece of wood. George Nakashima’s immortal oeuvre of work (which inspired this design) lends itself perfectly to getting the most out of feral hardwood such as what I chose for this top. How much and which imperfections are left to tell the story is of course in the eye of the beholder.
Anyway, I started experimenting with various different tools to see what might work best in flattening such a challenging top. The techniques I tried included a belt sander, a low angle jack plane with a toothed blade, a standard no.3 smoothing plane (45° frog) with a back bevel of 25° creating an effective pitch of 70° and a shop made fore plane with a blade pitched at 50° (aka York pitch).
The belt sander has always been one of my least favourite tools. It makes noise, it is all over the place and seems to be the best possible tool to turn a flat surface into the famous Valley of a Thousand Hills. What I found was that it is less harmful in such hard wood, but still not an option if you are aiming for a superior surface. The low angle Jack plane (12° bedding angle + 38° micro bevel for an effective pitch of 50° and a tight throat) worked diagonally to the grain clearly had the measure of the wonky grain, but would have taken too long for what would suffice for the bottom side of the top. I did not aim for a perfectly flat bottom side.
Next up was the back-bevelled smoothing plane. It worked even better (in terms of finish) than the low angle plane, but was difficult to push due to the high effective pitch and therefore even slower at removing material. It is also important to mention that this strategie seize to be effective in difficult grain when you try to take a fat shaving.
So I rolled the dice and tried the shop made fore plane (50° effective pitch) diagonal across the grain. It wreaked havoc in a semi controlled sort of way. This particular blade has a fairly substantial camber and it took no prisoners in the process of removing the necessary material in a timely fashion. In the pictures below you can see the characteristic scalloped appearance of a surface smarting from such treatment.
This is one of my attempts at manipulating the photos to highlight the pattern left by the plane.
The wooden plane in the picture below enforced the above damage. Of note in the picture is the bottles of water I consumed during this arduous labour of bellicosity.
Here we have an example of a part of the history of the tree that is often neglected to be told. Yes I know some of you will think I have lost the plot. Probably something along the lines of: “The #%$@&* hippy has been smoking too much pot.” The reality for me is however that the wood I in my collection have all sorts of imperfections and it would be impossible to create anything of reasonable size without these imperfections exposing themselves. I have therefore made peace with having to incorporate imperfections and try to design in such a way that the eccentricity of the stock enhance the aesthetics of the piece I am building.
Here are a few more tweaked pics with an array of tools that were used to tidy up the bottom side of the top.
Then finally it became time to employ some of the lessons learnt on the bottom side to the face side of the top. It took me three full days of planing at 45° to the grain with a toothed blade in a low angle jack plane to get the top as flat as I wanted it. The two pictures below were taken after the first day.
The dogs on my assembly table came in quite handy during this brutal process.
The toothed blade created these beautiful patterns in the areas that were approaching flatness.
This was the end of day two.
Once the entire (well almost) face side were in the same plane I removed the bulk of the rhombi left by the toothed blade using a no. 112 scraping plane. It was the first time I used this particular tool for a huge job like this. I prepared the blade the way that is recommended by my woodworking icon David Charlesworth. In my case a 45° main bevel, 50° polished micro bevel with a 75° burr set up in the plane with the blade leaning forward at 20°. The plane is an absolute joy to use when set up like this. You have to make sure you take very thin shavings of course. Some sanding with my shop made sanding planes took care of the rest of the rhombi.
While grappling with the rhombi I took short breaks to tidy up the cracks in the top. They all had lots of loose splinters of wood and other ancient bits of debris inhabiting their depths. This task was mainly accomplished by using a very old pocket knife that used to belong to my grandparents.
At this stage I shaped the curved ends of the top. As you can see I marked out two lines using my fingers as a fence. These lines guided the removal of waste to create a very gentle yet quite wide bevel. Once the bevel were established, the end grain area were rounded off ever so slightly using the same technique. My no. 9½ Stanley block plane did most of the donkey work and was then followed by a low angle smaller block plane, which was in turn followed by gentle sanding.
When I got a bit tired of the top I continued to chip away at the last bits of joinery.
Once the two aprons were fitted to the legs with very precise bridal joints, I started working on the massive beam that connects the legs at floor level. The Witpeer beam was laminated and squared up more than a year ago. It gave the wood a very generous time frame within which it could settle all possible disputes the fibres might care to raise (so to speak). It turns out that a very dense laminated beam like this stayed pretty much dead straight in all it’s dimensions, but managed to go out of square by what appeared to be a full mm. That was fixed by hand planing a face side and face edge perfectly square with each other and using those reference surfaces to square up the others with my electric planer.
I transferred the inside measurements of the joinery from the aprons to the beam.
Using the above reference point I took the beam to the Windsor leg to mark out the exact location of the other side of the fairly complex stopped bridal joint (my own name not necessarily correct terminology) which will marry these two structures.
This is how far I got with this joint at present.
It was now time to break in my precious polissior that one of my favourite woodworking personalities and über craftsmen Don Williams (of The Barn on Whiterun fame) sent me earlier this year. That entailed rubbing the heads of the grass/straw on a rough piece of scrap wood and tidying up the appearance on a spindle sander.
I can thoroughly recommend reading Don’s article on this epic tool from the past.
I used the Polissior to burnish the top after perfecting the finish with gradually increasing grid sander paper on a orbital sander. I went all the way to 600 grid and did two rounds of wiping the surface with a damp cloth to raise the grain before sanding it back down with the 600 grid. You can see the effect of the burnishing in the pictures below.
Aoife helped me to apply a tung oil/turpentine mixture. We kept the surface quite wet for 30 minutes by reapplying the mixture where the wood absorbed it and then wiped it down with a clean and dry cloth.
As you can see it was one of those unbelievably satisfying moments in woodworking where the wood rewards you for months of painstaking elbow grease. Kershout is simply one of the most beautiful species of wood on the planet. I want to reiterate that there were no pigment added what so ever. This is what it looks like after tung oil mixed with turps were applied!!
The top will now rest for two weeks before we will apply beeswax with the polissior. Stay tuned my brethren!!