The Chair – The Fingers (Part 2)

Without a doubt, this is the most difficult joint I have ever made. The following is the sum of my work over a Sunday afternoon, and the total completed amounted to one joint. I could have marked, sawn and finished a complete dovetailed drawer in this time.

We left off last time with the right side arm ready to join to the backrest …

In fact, I decided to join the left side instead since this was the side for which there was an extra section (but of lesser quality) should it be needed.

The face of the arm was covered in blue tape and clamped to the backrest to transfer finger dimensions …

When I previously experimented with marking I had used a sharp scratch awl. It still tended to tear the tape, and consequently I sharpened up a skinny Kiridashi. As it was a left-handed version I ground a small V to enable it to cut both ways.

Below is the traced result …

There needs to be a half-round at the end of a finger at the left side …

The holes were drilled …

This is what it looks like with the tape removed, ready for sawing …

It was an emotional build up to this point – once the holes were drilled to position the ends of the fingers for sawing I had reached the point of no return. There was nothing for it, so I grabbed the tenon saw and started cutting out the fingers …

It was at this point that my developing understanding of the joint recognised that there needed to be an extra finger here …

… and here …

The sander above is made up of cloth backed 120 grit glued into a round groove. It was used to smooth off the end of the fingers once they were rounded with rasps.

Below is the new finger on the backrest …

Now the arm is again covered in blue tape and clamped to the backrest …

… and the fingers are sawn out …

The fingers are rounded off (not shown here), and a test fit is close … but it needs tuning (not sure why I showed the back here since it is the front which is the reference side) …

This process consumed much of the afternoon. It was painfully slow. Do not be fooled by the few pictures. With a float or rasp a little amount is removed, and then the two sections are brought together again. And this is repeated with the joint slowly coming closer together … again … and again ...

Each time it is important to check that every piece is still square …

This is where I decided to stop. I may do a little more next weekend. The ends do bottom out when forced together.

The reverse side (back of the backrest). The yellow lines indicate the outer ends of the backrest, that is, where the shaping takes place …

The sections together on the bench …

A close up of the joint with dimensional lines. Again, the result looks a little looser here than it actually is. When gluing takes place the sections will be pushed together firmly. Even so the joins will benefit from tinted epoxy (with sawdust) to fill any gaps that may be present.

A close up of the rear …

Opinion – not as good as I hoped, better than I feared, but good enough to go forward.

Regards from Perth

Derek

February 2014