once more about pins…then I’ll stop for now

well, if you can stand it, here’s more about the pins that secure drawbored mortise-and-tenon joinery in 17th-century oak furniture. Pin shape, splits in the stock, deformation in the holes as a result of using the period bits, what Jennie Alexander & I call “piercer” bits, based on the most common term for bits in joiners’ inventories at that time. Not that the phrase is all that common, just that it’s used more than others. Here, see the pins have split the stile in a joined chest, this happens mostly on the tangential face of the oak. The splits start at the point in the hole where the bit tears up the end grain as it comes around…
small splits between two pins

Some joiners make very carefully-shaped pins, others use faceted ovals, even square shapes. As Alexander has pointed out, the facet/point usually hugs into the “spruck” where the bit comes around from long grain to end grain; you can see it here on this joined chest from Dedham, MA.

pins, etc, joined chest Dedham MA 1650-1680

Another Dedham chest shows pins that are effectively square. The split here is from a pin too large for its hole, and the use of the mitered shoulder, which has less bearing surface than a 90-degree shoulder.  

square pins

Here’s a slide shot by JA years ago, showing three types of bits, and their respective holes bored in oak.

gimlet & piercers
Next one’s pretty grubby, but shows the pin filling the weird shape of the hole. (See the top right hand part, just past 12 0’clock on this pin)
Savell cupboard
The next one has two kinds of pins; round-ish ones to secure the M&T joints, and square ones to attach the joined front of this chest to the board sides. Note the top round pin snapped when it was being trimmed, probably with a chisel.
Savell chest, joined front fixed to board sides
My take on pins is this. They are usually round, mostly, sometimes almost square, and often octagonal-to-round. there’s a lot of them in a joined chest. It does not pay to get too carried away making them carefully shaped. One detail that Alexander is always after me about, and rightfully so, is that the pin fills the holes. Mine tend to be tapered too quickly and therefore fill the hole sooner on the face of the joint, and not so much on the inside. Here is a joined stool from Essex County MA showing the pins on the inside. I’m working on mine.
17th-century joined stool; pins

For more about this subject in general, see https://pfollansbee.wordpress.com/?s=drawboring and if you missed the beginning of this leg of this subject, here is the previous post on it https://pfollansbee.wordpress.com/2010/11/19/piercer-table-bit-etc/

8 thoughts on “once more about pins…then I’ll stop for now

  1. Peter,
    As always, a hugely informative examination and clear explanation. I’ve just started on drawboring, and this discussion is quite timely. It was great to meet you last week and see your carving and other work first hand. I look forward to reading more, and visiting the shop again (maybe not around thanksgiving next time!)

  2. Jennie raises the point (in post below) about why pins on draw-bored joints stand proud of the joint and have slightly mushroomed heads. I thought that was a result of the bone dry pin being driven into the green joint, the joint then drying further, leaving the pin proud of the surface. Not so sure about the mushroomed head; perhaps a result of the trimming or paring work when originally made which would have appeared clean at first but not so clean once proud; or perhaps a result of wear and tear once it became proud of the surface.

  3. Peter:
    Your close up pictures of pins in action and grain disturbance are very helpful. However, no fault of yours, two are confusing. I goofed on the picture I took of the three boring bits. The bits are fine but the bored wood was reversed. We are looking at the exit grain disturbance on the back of the wood. I always bore clock wise. In the Savel picture the small drawboring pins show the typical grain disturbance, the large peg does not. This hole was either bored from the back the post or bored counter clockwise.
    Pins in period work indeed project slightly above the surface of the work. The pin is slightly tapered and at assembly is driven tightly into the workpiece. The top of the pin is flattened to surface. The pin is dry at the time of assembly. It is compressed by the workpiece. The workpiece is still slightly moist at time of assembly. As the workpiece dries it shrinks down the pin. The length of the long fibered pin remains essentially unchanged. As a result the pin stands proud of the workpiece. As Peter points out pins driven into the tangential plane of the workpiece will project about twice as much as those in the radial plane. The projecting portion of the pin now released from compression and absorbing moisture expands causing the head to be slightly rounded. The result is that we have a slightly projecting pin with a slightly mushroomed top. This situation allows the curious to determine if a period piece has its original pins.
    Careful visual inspection will confirm. A further test is to see if your fingernail will slide under the mushroomed head of the pin. It very well may. If you lack a period piece or permission to lovingly fondle one, use a piercer and drive home dry pins into both planes of a slightly moist workpiece and see in time what happens. Finally use a double blind test and simply feel which pin projects more and predict which face is which.
    If you agree you might put up my diagram of the life history of a pin and some shots of the Savel stool.
    Wood is Wonderful?

    • “Pins driven into the tangential plane of the work piece will project twice as much as those in the radial plane”?? I would expect just the opposite. A quarter sawn board will shrink less in width than a plain sawn board, but it will shrink more in thickness than a plain sawn board. So the pins should project more when driven in the radial surface.
      The tapered pins I put in kiln dried wood thirty years ago were originally planed off flush. They now protrude.

      • To W. Mickley:
        You are uite correct. I have managed to confue a simple topic! Peter uses the term “face” and your “surface” works as well.In will write on the blackboard 25 times:

        A dry pin driven into a moist radial face and trimmed to be flat with the face will in time project about twice as much as one driven into a tangential face.

        Thanks fo straightening me out.

        I qustion your comment about pin projection where both pin and and the wood it is driven into are kiln dried. I suspect that the kiln dried wood had some moisture in it at the time it was bored and then shrank down the pin.


      • I have a cupboard which I made from kiln dried wood in 1980. The pegs in the door frames were driven from the front face and planed flush on both the front and the back. Today they not only protrude on the front, but they are now recessed by a similar amount on the back side. All 16 pegs. So that it appears that actual movement of the pegs, rather than just shrinkage, is what occurred. The other old work that I still have also has protruding pegs, but most were never flush on the back side. However one oak window has the same protrusion/recess pattern as the cupboard.

  4. This is an interesting period of furniture to collect. I have been a collector of 16th & 17th century English and Dutch furniture for over forty five years and have assembled some very interesting pieces. The construction is what really excites me especially when I come upon a piece that is still in its original condition. This past week I found a small travelling gate leg table at a flea market that dates to the 1th century and is completely original. What makes me wonder how many dealers still have no clue to what they are selling especially if they thought my table was from the 1920’s. A fifty dollar bargain. Your pics on construction and seeing these oriiginal pegs is what people need to see this way they get a better idea of how early furniture was assemble. Thank you for sharing your pics for those who thurst for knowledge when it comes to period furniture.
    George Way

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