Pegs Their Use and Their Making (Timberbee)

From the Quicksilver Metaweb.

A question of Pegs

To many Lay people, the peg is often the quintessential element of a Timber Frame. The question is asked, "Do you use Nails, when you build them?" What is Often behind this question is, that the answer Must be "No", any other answer would Not be legitimate in the eyes of the questionnaire.

The Role of the Peg

What Many Lay people do not seem to understand is that it is Simply Not possible for a Nail to replace a Peg, in Many of it’s applications.

A peg, also, is not Always needed. As Peter McCurdy discovered in his Survey of the Great Tithing Barn at Harmondsworth.

A peg is said to have two main functions; * As a Fastener * As a Spring

The first is what we intuitively recognize as the role of the “Peg”. It is what is reflected in our speech, and our thought. It is, Also, a role which is shared by fasteners such as Nails.

The second role of the peg is Not as obvious, and, it requires more information to bring the reasons behind it to light;

Draw Bore

Draw Boring is the Intentional misalignment of the Peg Hole in the Mortise, with that of the Peg Hole in the tennon.

If the Peg Hole of the Mortise – A brace mortise in this case – is to be 1 ½ Inches from the Shoulder, and 2 Inches from the nose, then the misalignment – The Draw Bore – occurs in how the Peg Hole in the Tennon is drilled, In this case, this would be drilled 1 3/8 Inches from the Shoulder of the tennon, and 2 Inches from the nose.

Draw Bore often occurs in Two directions, But, for purposes of This discussion, it is Simpler to describe it in only One direction, it also still Works, in just the One direction.

===What does Draw Bore Do==== If you were to look down a peg hole, of an assembled Mortise and Tennon Joint – this Only applies to Mortise and Tennon Joints, not Lap Joints or Scarf Joints – you would see only see a Half Moon, as the peg hole for the Tennon.

When a peg is driven into this assembly, the misalignment of the holes Forces the peg to deform, there is No other way that the peg can continue forward, unless, it physically Breaks the Tennon, the peg may also end up driven into the body of the mortise, much as a nail is, after it has been deflected by the misalignment of the hole in the tennon, If, some care is not used.

Riven Pegs are very flexible, even more so if they are Green.

Misconceptions

One of the Chief Misconceptions of what Draw Bore does is the belief that this is meant to “Draw the Building Tighter”. That this, 1/8 to ¼ of an Inch of Draw Bore ultimately represents wood that is compacted by the driving of a peg.

This will not occur. Unless the relish of the tennon is “Blown out”, the draw bore will be maintained, and, the peg will remain deformed throughout it’s entire life.

What it Does

Though it is true that a Peg can be the difference between a “Tight” joint and a sloppy one, it does not necessarily represent it’s True Function.

What it Also does, in addition to Helping to tighten joints upon assembly, is that it acts as a Spring to Keep them tight over the life of a Structure As the Timbers undergo Drying. Something which a Nail cannot do.

The Peg places enormous pressure on the Tennon, in an assembled joint. As the Timbers shrink, the initial 1 ½ Inches that the peg hole was from the edge of the mortise declines – how much actual shrinkage will be determined by species and the local environment. The 1 ¼ Inches to 1 3/8 of an Inch the peg hole was from the shoulder of the tennon, in contrast, Does Not decline. Longitudinal shrinkage is infinitesimal in wood, Tangential shrinkage is not. This is what helps make Drawbore function.

As the pieces dry, Draw Bore increases, as does the pressure upon the peg, and, consequently, pressure on the tennon to move in the direction of the Mortise, creating a “Desire” for the joint to Grow, tighter, as it ages.

A nail would be unable to achieve this.

Objections to Draw Boring within the Timber Framing Community

One of the Key objections has been; * It is “Impossible” to know where to drill a tennon prior to assembly * Pegs Break when forced into a Draw Bored Hole * The process of Driving in the peg Severely Damages Joinery

These are more questions of layout, technique, and the manner in which the peg was made, than reality. For Some [Timber_Framing_Factions_(Timberbee)| Bensonites and Mappers], The question of where to drill a tennon can become an increasingly complex issue. And, early on in the Timber Framing Revival, Almost all tennons were bored Only after the joints had been assembled, causing, whole practices to evolve which centered around the problem of trying to drill an Assembled frame in the air.

When a peg neither serves to draw a frame together during assembly, nor to act to keep it tight throughout it’s life, it’s value diminishes greatly, to the point where it’s role becomes entirely negligible, becoming more a “Statement” than a practical necessity.

Now, the answer to, “Do you use nails?” Takes on a more sinister, and hypocritical form. For, Pegs are no longer necessary where they do not perform their traditional functions. Though, the Client has come, rightly or wrongly, to judge on us their inclusion.

One solution to this dilemma is to use “Fake” pegs, and cause the Owners to believe that, yes, their frame is a Genuine product for here is the evidence.

The Other solution, has been, to “Re-Educate” the client. The common theme here is; “We are making a Better Timber Frame, this is the 21st Century meeting the 16th.”

Why Johny Doesn't Draw Bore -- It's the Peg

Riven Vs. Sawn

When stress is placed upon wood, most Catastrophic failures First occur parallel to the grain. For most wood, this is it's Weakest Structural Property.

You can see this for yourself by grasping a Wooden broom handle, and striking it against any solid, immovable, object -- If you do this. Watch out for Flying wood, the Broom Handle Will shatter. If you broke the broomstick, what you will see is that the piece in your hand, considerably shorter now, will have a very sharp, oblique, and, almost smooth, point. It will also have broken along a Plane, this surface will be fairly flat, and striated.

What has happened here is that Shear has occurred Parallel to the Grain.

If you take the longest of the remaining pieces, and set it as if you were going to break it over your knee, and Slowly begin exerting pressure, to the point where the wood fibers are beginning to rupture, and continue to apply this pressure until the piece has Finally and Completely Snappe, then, If the break is jagged, and Stringy, rather than exhibiting the smooth, sharp, break that the prior one does, then what you have done is caused the broomstick to fail Perpendicular to the grain.

It's this Very demonstration, which reveals what's going on in the World of Pegs, particularly, Riven vs. Sawn.

The Sawn Peg

The Sawn peg is nothing more than a broomstick.
Stock is first sawn into Boards, from the log, and then, further, sawn into "Blanks", in preperation for the lathe, where it is then turned, and now, there is the choice, Broomstick, on one hand, Peg on the other. To be a Broomstick, it will be varnished, attached to a Head of Bristles, and put into the hands of one who sees it's value.

To be a Peg, it will be cut into appropriate Lengths, sharpened to a blunt point -- not unlike that of a pencil -- packaged, and shipped to the awaiting Many. And, this is where the problems begin, for the Framer using Draw Bore with these.

The Riven Peg

Like the Sawn peg, the process begins with the Log.
Unlike the Sawn peg, Stock is Split, Directly, from Sections of the log. In preperation for this, the Log is examined for inherent flaws, such as knots, cats eyes -- Inclusions -- and spiral grain, all the things which, while not making a weaker peg, will wasted material, and, wasted time when fashioning the peg.

The log is then cut into sections, or Billets which are Exactly the length the finished peg will be.

From here, one practice is the Squaring of the log, the transformation of the Billet to the "Cant". This removes Bark, and a Bulk of the sapwood.

From here the Cant is, ultimately, split into individual blanks, generally with the use of the Froe. It is these blanks which will, then, be shaped into the Peg.

How the Riven Peg differs from the Sawn is that, in the Split, or Riven, peg, grain runs true from tip to Butt.

If you were to Split out, a six foot piece, and grasp it, as you did the Broomstick, and strike it, in the Same manner, against the Same obstacle, with the Same force, you would not get the Same break.

In most cases, you would not get a break at all; * First, the wood is likely to be Green, what this means to You, is that it is more flexible, you should have noticed that the Riven piece was a bit more "Whip-Like" than the Broomstick.

• Secondly, if you Do get a break, that breakage would more closely resemble what happened when you broke the broomstick over your knee -- if you got a jagged break.

If, you Did get a break, this one is likely to be Perpendicular to the piece -- Very blunt and square, Not sharp at all -- and ragged, or, "Fuzzy"

This is the main difference between "Sawn" and "Riven". They Both Break in the same manner, under pressure, as they are driven, but, the Sawn peg will break somewhere down it's length, which means, To the Framer, out of sight, somewhere in the peg hole.

The Riven Peg, on the other hand, will split.

It's the Exact Same breakage -- Shear Parallel to the grain, however, When the Riven peg splits, because it is meeting incredible resistance, it will begin splitting at the Top.

The solution to a Riven pegs breakage is... To saw off the uppermost bit, and reveal unbroken, or nearly so, Stock, and, continue Driving. It is One reason why Pegs are made longer than needed.

The solution, when a Sawn peg breaks is... to Decide whether the peg has gone in enough to work. If the answer to that is No, then, the peg Must be extracted. If the Sawn peg cannot fully be extracted, the next decision is whether to Drill it out. Not Good choices.

How this Answers the Question of Breakage

Most pegs in use today are Sawn, and sawn from Sawn stock, not Riven stock. The Broomstick was used, in the above example, because, it to, is produced in this same way. Most pegs are made in a fairly Identical fashion as broomsticks, but, rather than ending up attached to a Head of Bristles, they are sawn down to One foot lengths, and sharpened.

When that Roundpeg – For, Most of this type of peg is Also round, very much different that the Traditional peg which is almost always Octagonal -- is inserted into a Peg Hole and struck, with a mallet, it shatters, very much like when that Broomstick was struck against an immovable object.

Moreover, Most of these pegs are shaped when they are Bone Dry, so they don’t shrink from the time they are turned, to the time they are used, and thus, are Exactly the same size as the hole they are being driven into, unless they were shaped slightly undersized, But, since most of those using this type of pegs are Unable to use drawbore, due to problems of breakage, an undersized Round peg, would simply fall out of the peg hole, and thus, serve no purpose at all.

Breakage, Draw Boring, and the Sawn Peg

When a Framer attempts to use both Draw Bore and Sawn, Round, Dry pegs, the breakage rate of the pegs can be up to 70%.

This means that Up to 7 out of every 10 pegs driven, will not be driven home, and Must be, instead, extracted and a new peg inserted.

In practice, you can Easily expect half the pegs to break, and of these, at least Half will Need to be removed, and a new peg to be tried in it’s place. What it means, Most of all, is that, overall, the bulk of these pegs will Not be fully seated, and Draw Bore will be Costly, and inefficient, with extremely Negative results, and few positive ones, for, the Builder, using this type of peg, is unlikely to reap any benefits of this system.

Conclusion

Draw Boring is a “Device” which has evolved over the countless millennia which Human Beings have practiced Woodworking. It speaks to the Nature of wood, and the desires of the craftsman to instill ongoing flexibility and strength within the piece, it is a dynamic process which brings the Frame, the cabinet, the chair alive, in a way which Modern Fasteners Do Not Do.

This is not to say that Modern Fasteners, shear Rings, and Whatnot, do not have their place. They Do. But it that place is not necessarily to replace the Draw Bored Hand Riven peg