Introduction: My entry is a woodworker’s tool for boring holes in wood called a Bit Brace.

Fig. 1. above Collection of 19th Century Bit Braces, Pacific Northwest Tool Collectors 2010 Best in the West (BITW). Personal photograph by author. 2010.

Fig. 3A. Bourdichon, Jean. Les Quartre Etats De La Societe (The Four Conditions of Society:Work). 1490. Illumination on parchment. Ecole Nationale Des Beaux-Arts, Paris.

Fig. 3B. Detail

I will show early examples of this tool in art, archaeology and a modern equivalent. I will discuss how I made the tool with commentary on ways that it may have been created in period including materials that it was made from. I will also discuss why this simple tool is a milestone in medieval technology. I will demonstrate how the tool is used and some of the ways I intend to use it in the future.

What: A Bit Brace (Boat Sway, or Belly Brace) (Fig. 1) is tool that uses rotary motion for boring holes as opposed the reciprocal motion used in Augers. An Augur is bit set into a two handed handle. Early Bit Braces were thought to be used as pilot holes for Augers in thick wood and making small holes in thinner pieces (Salaman 92).

Fig. 2.  MASTER of the Duke of Bedford. Building of the Ark. 1423. Illumination on parchment. British Library, London. 41 x 28 cm

Fig. 4A. Campin, Robert. Merode Altarpiece-right wing. 1425. Triptych, Oil on wood. The Cloisters, Metropolitan Museum of Art, New York.

Fig. 4B. Detail of St Joseph

The tool is used by carpenters, ship builders, chair makers and coopers. The Bit brace is thought to originate in Belgium Dutch based on the Flemish painting c 1423 (Fig. 2) (White 112) (Rapp 4).

Significance: The Bit Brace is the first instance of a double crank to appear in woodworking technology. “Historians are divided as to camshaft or the double crank should rank as a major contribution to technical advance” (Rapp 4). The double crank turns reciprocating motion into a rotary motion and the stepping stone to crank shafts and the inventiveness of men like Leonardo da Vinci (1452–1519) and the incorporation of gears.

Inspiration: My inspiration for this project was a painting I had seen reproduced several times in several places. Les quartre etats de la Societe (The Four Conditions of Society: Work) by Jean Bourdichon c 1490 (Fig. 3A & B) currently on display at Ecole Nationale des Beaux-Arts, Paris. As I do the woodworking demo at June Fair I continually want to improve the period character of the “shop” and this was the next step. I have been using a modern Bit Brace when I demonstrate how to join two boards for the bottom of a bucket or making holes for stool legs. I would then show a copy of the painting to justify the use of the tool.

Research: While attending a tool collectors show I had the opportunity to briefly talk to Reg Eaton[1], a recognized expert and author in the field of Bit Braces, and asked him about the earliest known Bit Brace.  He told me about the Mary Rose shipwreck (c 1545) and, of course, referred me to his book. Mr. Eaton said that he made reference to some early examples in art in his book but there is nothing in the archeological record from the Mary Rose Bit Braces until 1596. The hunt was on!

I was able to cross check and identify the earliest illustrations c 1423 AD (Fig. 2) and c 1425 (Fig. 4A). I also examined the sketch of the Mary Rose Bit Brace’s to determine how the pad was attached (Fig. 5A & B).

The Mary Rose was the four masted flagship of Henry the VIII. It was launched July 1511 ("The Mary Roose") and sank on 19 July 1545. The wreck of the Mary Rose was rediscovered in 1971 and salvaged in 1982 by the Mary Rose Trust.  Recovered was a set of carpentry tools (Fig. 6) among them were eleven Bit Braces that fell into three styles. There was only one Bit Brace that was considered a type three due to its shape (81A3094/1-2) (Fig. 5A). The dimensions provided by the Trust were similar to a modern Bit Brace. I decided to base my brace on the Type 3. The species of wood for that Bit Brace was not identified. However as a group Elm, Alder, Beech, Oak and Ash were used (Gardiner 302).

The bit had eroded away so I went back to the art and research to determine its shape and size I wanted. Early bits used were a gouge, spoon or crude spiral shape bit. The difference between a gouge and spoon are difficult to determine from the art as they look similar and are usually misidentified. In fact some early American bits shown in museum photos can only be properly identified by physical examination. I knew from working with spoon bits that their advantage was for changing direction after starting the bore. The twisted bit was not illustrated in the three early examples that I was trying to base my brace on. I choose a gouge style for this project. 

The length of the bit was the next challenge. As I intended to make the bits myself, I decided to follow the example of making bits from concrete nails. This is a much shorter bit than is illustrated in the art. However as I would be using this brace to demonstrate drilling short holes for dowel pins in bucket bottoms, I felt I did not need them to be very long. I will make a brace with a purchased spoon bit for demonstrating drilling holes for stool legs.

Bit Brace #1 (Fig. 7). My prototype is out of Douglas Fir due to cost. The cost of Douglas Fir is about $5.58 per 10 ft stick of 2x6. The cost of Ash is about $45.50 for the same size.

I first laid out the pattern on the standard modern 2x6 board.  Using a Turning Saw I removed the majority of the waste to within a ¼ to ½ inch of the lay out line (Fig.10A & B). I did save the largest piece for the Head Pad. There was wander and taper in the cut as a turning saw was not held as straight as it should have been. I started to clean up the cut by just whittling away the excess with a carving knife as would have been done in period but soon decided to use the band saw. The band saw is not period but does save a lot of time. I removed the material to the lay out lines.  I then returned to clean up and round the edges with my carving knife.

Next I cut out the Head Pad. I did use the band saw to clean up and put the taper on the Head Pad modeling after the sketch in “Before the Mast”. I then drilled a mortise in the Head Pad using a modern Forsner bit. In Period I suspect that they would have either used another Bit Brace or used a knife to make the hole. I also decided that since I was using Douglas Fir I would put a ferrule on the Foot as when the bit is installed I expected the wood to split. This is a period method of preventing a split on most tools. If you examine The Merode Altarpiece (Fig. 4B) you will see that his Bit Brace has a ferrule. I used a piece of 1 inch copper pipe that was cut to down. This is an important order of steps because now I had the sizes to create tenons on the brace body.

I carved the Head tenon using my carving knife and a chisel to a loose fit to the Head Pad. In the descriptions, the Head Pad has a wood or metal peg to keep it on the brace. I decided to use a cut nail as a peg so that during my demonstrations I can show that there is no other mechanism such as a bearing in the Head Pad. The Foot tenon gave me a bit of trouble as it split while carving. I then cut a 3/4 inch pipe to correct this. In my hurry I ended up with an out of true ferrule.

As I stated above I forged the bits from concrete nails. To set the Bit I did several trial runs in Douglas Fir and in Ash blanks before setting them into the Braces. This was to test the concept and to determine the correct pilot hole size that is needed. I drilled a pilot hole and then I heated up the shank to a peacock color or about 540F. By the time I moved the bit to the wood and got it aligned, the temp reached 400F. Any hotter and the shank would char the wood fibers making it a loose fit and the bit would fall out. This did happen on the Fir blanks.

Bit Brace #2 (Fig. 8). Again I used Douglas Fir but this time I enlarged the body to better fit my hand and this time I used a 2x10 board. I used the same process as #1 but as I was not happy with how it looked so I used 60, 80 and 150 grit sandpaper to remove most of the tool marks. I also tried a round Head Pad.

Bit Brace #3. In this version I decided to use Ash as the wood and this board was a true 2in thick by 6.5in wide. Based in the dimensions of the Type-3 Bit Brace (81A3094/1-2) (Fig. 5A) I cut off a knot free section 17in long which is larger to accommodate a better fit for my hand. I used the band saw to rip the section to 1 1/4in piece. I started to use the turning saw but I could not get a good cut as my saw was not sharp enough. Instead of taking another weekend to sharpen the saw I went straight to the band saw. This version does not have a Foot ferrule as does the Type-3 Bit Brace.

Hands on demonstration:

What I learned: I had several lessons reinforced and new tricks in the process. Douglas fir is too soft for a Bit Brace under standard use. The concrete nails that I was able to forge into bits were fun and I learned heat management but for a working Bit Brace the tang is too short. I also found that I ended up with bits that yielded about the same hole size when I was going for several sizes. You need sharp tools! I was re-sharpening many times during a single work session.

Conclusion: I think that these Braces and the ones I plan to make will be a great addition to my woodworking demo.

Fig. 5A. Gardiner, Julie, Michael J. Allen, and Mary Anne. Alburger. "8." Before the Mast: Life and Death aboard the Mary Rose. Portsmouth: Mary Rose Trust, 2005. 301.	Fig. 5B. Gardiner, Julie, Michael J. Allen, and Mary Anne. Alburger. "8." Before the Mast: Life and Death aboard the Mary Rose. Portsmouth: Mary Rose Trust, 2005. 301.	Fig. 6.  "File:MaryRose-carpentry Tools1.jpg." Wikimedia Commons. Mary Rose Trust, 10 Nov. 2009. Web. 15 June 2011. <http://commons.wikimedia.org/wiki/File:MaryRose-carpentry_tools1.jpg>.

II.    Works Cited

Works Cited

Primary:

"File:MaryRose-carpentry Tools1.jpg." Wikimedia Commons. Mary Rose Trust, 10 Nov. 2009. Web. 15 June 2011. <http://commons.wikimedia.org/wiki/File:MaryRose-carpentry_tools1.jpg>.

Gardiner, Julie, Michael J. Allen, and Mary Anne. Alburger. "8." Before the Mast: Life and Death aboard the Mary Rose. Portsmouth: Mary Rose Trust, 2005. 300-03. Print.

Secondary:

Bourdichon, Jean. Les Quartre Etats De La Societe (The Four Conditions of Society: Work). 1490. Illumination on parchment. Ecole Nationale Des Beaux-Arts, Paris.

Campin, Robert. Merode Altarpiece. 1425. Triptych, Oil on wood. The Cloisters, Metropolitan Museum of Art, New York. Robert Campin (c. 1375 – 26 April 1444), now usually identified as the artist known as the Master of Flémalle

MASTER of the Duke of Bedford. Building of the Ark. 1423. Illumination on parchment. British Library, London. 41 x 28 cm

Other:

Burton, Mike. Make Your Own Woodworking Tools. East Petersburg, PA: Fox Chapel Pub., 2006. Print.

Eaton, Reg. The Ultimate Brace: A Unique Product of Victorian Sheffield. Norfolk, England: Erica Jane Pub., 1989. 7. Print.

Goodman, W. L. The History of Woodworking Tools. London: Bell & Sons, 1964. Print.

Mercer, Henry C. Ancient Carpenters' Tools: Illustrated and Explained, Together with the Implements of the Lumberman, Joiner, and Cabinet-maker in Use in the Eighteenth Century. 5th ed. Mineola, NY: Dover Publications, 2000. 205-08. Print.

Mussey, Robert. "Old Finishes." Fine Woodworking 33 (1982): 71-75. Print.

RAPP, George. The Traditional Tools of the Carpenter and Other Craftsmen. Vol. 2. London: Arnold & Walker, 1975. 2-5. Print.

Salaman, R. A., and Philip Walker. Dictionary of Woodworking Tools: C. 1700-1970 and Tools of Allied Trades. 1989 ed. Mendham, NJ: Astragal, 1997. 90-101. Print.

White, Lynn. Medieval Technology and Social Change. London: Oxford UP, 1962. 112. Print.

Contact information: Mateusz z Plocka,  mka Matt Henson,

 hl_matuesz@yahoo.com, 360-509-8925