Lost Art Press

Author: meghanlostartpress

Dovetail Marking System

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This is an excerpt from “The Solution at Hand” by Robert Wearing.

There are many types of dovetail markers and as many methods of using them, but I like to think that this marker, A, and its method is pre-eminent.

The plate is made from a piece of 20 gauge brass, steel or alloy 5-1/2″ x 3″ (140 mm x 75 mm). This should be sawn and not cut with snips as these may permanently distort it. Drill the four 5 mm (3/16″) and three 3/32″ (1 mm) corner holes, then sufficient smaller holes to get in a hacksaw blade to cut out the dovetail angle and the two slots. File to shape with great care, rounding the external corners and softening the edges. From an accurate centre line, file the two nicks as shown in B. The bar is a piece of brass channel 3/8″ x 3/8″ x 1/16″ (10 mm x 10 mm x 1.5 mm) and it has one threaded hole and a slot. The hole is threaded 2BA. A sliding block is fitted below the slot and this, too, is threaded 2BA. The bar is secured to the plate, preferably with a pair of 2BA electrical terminals or with wing nuts and washers, C.

Prepare the components and gauge to thickness on the piece which is to contain the tails, D. Choose a suitable bevel-edged chisel that is only slightly smaller than the chosen size of pin, E. Place the gauge on the work and adjust the bar to give a width on the gauge line only slightly more than the chisel size, F. True up the bar with the edge of the gauge, either by a try square or against the edge of the wood. For angled dovetails use a sliding bevel on the angle already on the wood.

The two outside or half pins must be a little larger than half size, so, with a pencil, mark down the two outside centre lines to achieve this effect. About 1/8″ (3 mm) is usual for medium-sized dovetails. The distance between these two lines is divided equally in the standard way to give the centre lines of all the pins, G. Alternatively a rapid calculator can be made to fix centre lines by drawing equispaced converging lines on a piece of plywood as in H. The horizontal lines are parallel, and the end of the piece of wood is offered up to the required number of converging lines and kept parallel to the horizontals. The centre lines are then easily picked off, J.

The gauge is now placed on the wood with the nick over each centre line in turn for the pins to be marked, ideally with a fine ballpoint pen, K. Shellac brushed on gives the surface a “bite” on which to mark. On the end grain the square marking is done with a marking awl, which provides a small groove into which the chisel can be put decisively should there be any error in sawing. Beginners can run a thick pencil into it. Two pencil lines will be formed, and one line should be removed with the saw, L. The two pieces are held together for the marking of the second piece, O. A pair of holding brackets, M, is useful for this process; one will do for small work. The two pieces are held to the bracket with light G cramps.

A dovetail marking knife is essential for fine dovetails but is useful for all sizes, N. It is made from a piece of tool steel 4″-5″ (100 mm-125 mm) long by 1/2″ x 1/16″ (12 mm x 1.5 mm); a piece from a power hacksaw blade is very suitable. Both the little bevels are on the same side, giving a left-hand and a right-hand knife. In use, O, the flat side is held hard against the dovetail, and this tool will get into the most inaccessible corner where the marking awl or pencil never got in the past.

The holding bracket, M, has a further use when the front or rear corner is to be mitred to take a groove, rebate or moulding. The mitre is often, though not necessarily, at 45°. But if the pieces to be joined are not equal thicknesses, the angle cannot be 45°. What is important, however, is that the sum of the two angles should be 90°.

The remaining six diagrams, P-U, show how, when the pieces are held at 90°, both angles can be marked from the same edge, using a sliding bevel.

— Meghan B.

Making a Carving/Marking Knife

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This is an excerpt from “Making & Mastering Wood Planes” by David Finck.

The blades on most marking and carving knives feel too thick and bulky for my taste. The types of knives shown (above) are easily made and perform beautifully for marking and also for carving delicate details. Discarded saber-saw blades make good knife blanks, combining springiness and good edge retention. Shape the blade slowly and carefully with a grinding wheel, taking care not to draw the temper of the steel.

Alternatively, this project provides a good opportunity to become acquainted with the basics of heat-treating metal—annealing, hardening, and tempering—which can be done easily on this small scale. The advantage is that the blank may be shaped easily with the steel in a softened state, without fear of ruining the temper, then re-hardened and re-tempered.

Heat-treating employs high-temperature heat sources and potentially flammable materials. Caution must be taken. Use gloves and safety glasses, and it is wise to have a fire extinguisher on hand. First anneal, or soften, the steel. Hold the knife blank with vise grips and heat the end that will become the cutting edge with a propane torch until it is cherry red. It is easiest to observe the colors of annealing and hardening in a darkened shop. Allow the blade to cool slowly by thrusting the heated blade into a can of wood ashes. When it is at room temperature, the metal can be worked with a file, grinder, or belt sander, with no concern for overheating the steel.

When the blade has been shaped, harden it by heating it to cherry-red and then quenching the blade in a can filled with motor oil or water, swirling it around until the metal has cooled. The blank should now be brittle-hard. To harden it properly, you must know the type of steel and the appropriate medium for quenching (which could be water, oil, or various inert gases), although water usually works well enough. Buff one face of the knife end of the blank to a shine with 150-grit wet-or-dry sandpaper in order to see the run of colors during the tempering process. Apply the torch, fitted with a heat spreader, to the edge of the knife blank opposite the cutting edge, and heat the edge very gently (from a distance).

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Be aware that the thinnest part of the blade will heat fastest, so keep the heat away from this area. The metal will turn a straw color and then indigo. This progression of colors moves rapidly across the blade from the hotter edge to the cooler edge. When the cutting edge has acquired a straw tinge, quickly quench it in the motor oil or water to arrest the tempering process. Indigo-colored metal is too soft to hold an edge; straw-colored is just right. If you undershot, heat the blade a bit more and quench it again. If you overshot the mark, reharden the blade and try tempering it again. (See Alexander Weygers’s book The Making of Tools for more information on heat-treating.)

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Next, saw an oversized handle blank in half and rout out a cavity that will accept the shank of the blade. Epoxy the blade into the cavity and glue the two halves together with yellow glue in one operation. (Alternatively, you may use polyurethane glue for the entire operation.) When the adhesives have dried, wrap the blade several times with electrician’s tape or sink it into a cork to guard against cuts. Shape the handle with the band saw, rasps, files, and sandpaper. Remove the tape and hone the edge.

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— Meghan B.

Seasoning or Drying of Wood

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Air drying of European oak. A neatly stickered pile of timber air drying at Nidd Valley Saw Mill, Dacre Banks, North Yorkshire, England.

This is an excerpt from “Cut & Dried: A Woodworker’s Guide to Timber Technology” by Richard Jones.

Seasoning and drying of wood describe the same thing: reducing the moisture content of boards or planks thus bringing them into a dry-enough condition to use.

Acclimatising already-dried wood (acclimating in U.S. parlance) to the conditions in your workshop, or bringing it to a condition where it suits its final location as a piece of furniture or woodwork, is a different process to seasoning or drying wood. This subject (is) covered in section 6.12, Allowing for Changes in Wood Moisture Content.

There are several advantages of using dried wood.

Drying wood:

• Reduces its weight.

• Increases its strength and stiffness.

• Pre-shrinks it.

• Makes it more pleasant to handle.

• Reduces the chance of insect pest infestation leading to wood damage.

• Reduces warp and distortion of the wood in service because the drying process largely reveals any such tendencies in advance of constructing furniture and other wooden artefacts.

• The resin of resinous softwoods is hardened during higher temperature stages of the drying process in conventional kilns, making the resin less likely to weep out onto the surface of finished work.

• The end result of most machine and hand-tool operations are more predictable.

• Paints and polishes adhere better to dry wood.

• Modern adhesives formulations, in nearly every case, work best on dry wood.

• Wood preservatives and fire retardants penetrate dry wood better.

• Dry wood doesn’t spread damp to adjacent materials and objects.

• There is no fungal activity in wood dried to below 22 percent MC.

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Cross section of a board illustrating the three zones used to describe a moisture gradient, i.e., the core, intermediate zone and the shell. This is convenient but there aren’t actually distinct lines between each zone.

Apart from traditional green woodworking briefly described in section 6.9, there are some situations where undried wood has distinct advantages:

• It’s easier to drive screws, staples and nails into undried wood, and the wood is also less likely to split during nailing, although wood shrinkage may later lead to splitting.

• Screws, staples and nails driven into wet wood go rusty and this increases their holding power. Pallet and potato box manufacturers use partially dried wood for this reason.

• Cutting, shaping and working the wood requires less power, a characteristic often taken advantage of by carvers, turners, in steam bending, green woodworking etc.

The preferred moisture content of wood varies with its planned end use (see section 6.10) but to summarise, about 19 percent MC suits outdoor wooden artefacts; wood for internal furniture in the U.K. should generally be made out of material between about 7 and 12 percent MC. This MC range suits typical seasonal RH values for most British habitable buildings, i.e., about 35 percent RH in winter to 65 percent RH in summer. These numbers are similar to those experienced in coastal regions of North America. On the other hand, in central and northern areas of North America, the typical RH of habitable buildings tends to be somewhat lower at about 20 percent RH in winter (which assumes no artificial humidification system is installed in the building to maintain higher RH values) to 50 percent RH in summer, equating to wood MC values of 5 percent to 9 percent MC. Wood at various moisture contents between 12 percent and 18 percent is suitable for a variety of construction work and joinery in heated sheltered locations, sheltered unheated locations and for exterior joinery.

The two most common methods for drying wood are air drying and kiln drying. The methods are often used in conjunction. For example, it’s a common practice to partially air dry and follow up with a kiln-drying cycle. Within the two broad categories of air drying and kiln drying there are sub-categories. Air drying, for instance, breaks down into traditional air drying, accelerated air drying, forced air drying, low-temperature warehouse pre-drying and drying in climate chambers.

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End racking. Sycamore planks “end reared” and well-spaced apart. Sycamore is very prone to fungal growth if surface moisture is present so this practice of rearing the planks immediately after conversion into boards is quite common. Stickering the planks horizontally in piles straight after conversion may lead to the stickers trapping water and staining is the likely end result. Sticker-stained planks are unusable for show parts of furniture and sell at much-reduced prices to the upholstered furniture market.

Kiln dryer configurations and types are varied. Conventional medium-temperature kiln drying is the first and predominant form. Conventional kilns, by definition, operate at temperatures below 100 degrees C or 212 degrees F. The second most common kiln type is the low-temperature dehumidification drying kiln. The smallest versions of this type can generally only reach a high temperature of about 115 degrees F (46 degrees C), but large units will easily achieve 150 degrees F (65.5 degrees C). Thirdly, there is solar kiln drying. Lastly there are progressive kilns, which are uncommon – the only working ones I am aware of in the U.K. at the time of writing are owned by BSW Timber. With the exception of progressive kilns, a kiln is loaded and closed. A drying cycle is run through and then the kiln is emptied, ready for another batch.

— Meghan B.

Bend and Screw the Hinges for the Schoolbox

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Saw the extents of the mortise for the strap hinges, then chisel away the waste between.

This is an excerpt from “The Joiner and Cabinet-Maker” By Anonymous, Christopher Schwarz and Joel Moskowitz.

Good luck finding steel hinges for this project that have the right look and bend in the right place to fit in the partition. I was unsuccessful in finding some off-the-rack hinges to make this part easy. But altering your hinges to fit is easy work – the barrier for most woodworkers is that hinges are made of metal and that can sap your confidence.

Don’t let it. There are lots of cool steel strap hinges out there that are sold with straight-as-an-arrow leaves. Bending them is simple work with just a metal-jawed vise and a hammer. If you still have some trepidation, purchase an extra hinge to practice on.

These hinges are placed using the same rules for placing the crossstrengtheners on the Packing Box. First calculate the overall length of the box. Position the hinges so their centerlines are half this distance apart.

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Install the hinge with a single screw. Then mark where the leaf intersects the case. Make this mark underneath the leaf.

The hinges are recessed into the top edge and face of the back of the Schoolbox. First, cut away the notch on the top edge of the box for the hinges. Install the unbent hinges into the mortise using the screw hole that is nearest to the hinge pin. Then mark where you want to bend the leaf. Mark your bending line underneath the hinge, right up against the back of the box. Remember: It’s not like folding paper. You need to allow for the thickness of the leaf when bending.

Secure the leaf in a metal-jawed vise so that the leaf you want to bend sticks up from the vise. Clamp the jaws right below the line you marked. Use a hammer to tap the leaf to shape. You want to bend the leaf so that the leaf needs to be recessed into the back.

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Clamp the leaf and tap it with a hammer to bend it to a 90° angle. If all goes to plan the leaf should fit against the inside of the Schoolbox. Trace around it, mortise it flush and the hinge should then line up with your original screw hole.

Hold the hinge in its mortise again. Then trace around the hinge to mortise the hinge flush to the inside of the case (this will allow the partition to be removed). Waste away the area where the leaf should go.

Screw the hinges to the carcase of the Schoolbox and get ready to attach the lid. The lid should be slightly oversized because things might shift around during installation. Plus you never know how the slop in the hinge barrels will affect how the top fits.

Set the Schoolbox on its back and elevate it on some spacers. Position the lid on the benchtop and let the hinges fall onto the lid. Drive one screw into each hinge and see how things work.

Once the lid is positioned where you want it, let the lid fall onto the workbench and drive the remainder of the screws. Now you can trim the lid so there’s about 1/16″ of overhang all around. That should be enough for most environments. If you live in an area with wild humidity swings, give yourself 1/8″ of overhang on the front.

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Line up the lid as best you can and then attach the hinges to the lid using one screw in each leaf. Note how the Schoolbox is elevated on shims that make the leaves fall without any gaps between the leaves and the lid.

Now you can fix the lock’s hasp into the lid. This is a Friday job (meaning it’s easy). Lock the hasp onto the lockset. Then drop the lid onto the hasp. The hasp has two nibs on it. Strike the lid right where the hasp is. This dents the lid right where these two nibs are.

Unlock the hasp, nestle it into the nibs and trace around the hasp. By this point you should know the drill: Score the waste with a chisel. Remove it with a router plane or a chisel. Then screw the hasp to the underside of the lid.

As far as woodworking goes, you’re almost done. All that is left is to install the moulding around the lid. This moulding receives a chamfer or a bevel that is identical to the one you planed onto the skirt moulding.

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Shut the lid and feel all around the edges to see if the lid is squarely on the box. If it’s not, you can shift things around a bit at this point to improve the position of the lid. The two screws allow some pivoting. Do this carefully.

You also can cut the moulding and miter it just like you did the skirt moulding. However, there is one small difference when installing the lid moulding. You have some cross-grain problems that you didn’t have with the skirt moulding. The lid’s return moulding has its grain running at 90° to the grain of the lid.

Here’s how you deal with it: Glue and nail the front piece of moulding just like you did on the front piece of skirt moulding. When you install the returns, glue the miters in the same way you glued the miters for the skirt moulding. But when you glue the back of the lid moulding to the lid, glue only the first few inches up by the miter. Leave the rest of the moulding dry.

Nail the entire moulding, however. Nail through each miter and into the lid. The glue at the front will keep the miter tight. The nails at the unglued area at the back will allow the lid to move without things splitting or blowing apart. Well, that’s the plan at least. And it’s a good plan if you used Eastern white pine for this project. It moves little in service. If, however, you used flat-sawn red oak for your Schoolbox, then keep your fingers crossed.

— Meghan B.

Make and Use a Straw Polissoir

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This is an excerpt from “To Make as Perfectly as Possible: Roubo on Marquetry” by  André-Jacob Roubo; translation by Donald C. Williams, Michele Pietryka-Pagán & Philippe Lafargue.

One influential tool that was unknown to me at the start of this project is a polissoir (polisher), which I call a corn straw burnisher. Roubo offers fewer than 100 words describing the tool and its use, yet that tool has fundamentally changed parts of the way I work. As the last tool to touch the surface prior to the application of finish, or in some instances the tool that actually applies the finish, vigorously scouring the surface with it imparts radiance to the substrate that cannot be adequately described. It must be experienced.

Fabricating your own burnisher is fairly easy, and the raw materials are no farther away than any straw broom.

You will need a hank of straws between 1″ to 2″ in diameter. Take your bundle of straws and bind them together with several hose clamps of the appropriate size side-by-side, leaving about 1/2″ of straw sticking out at one end. Leave a little gap between the hose clamps about halfway down the length of the bundle. At this opening, wick in a copious amount of glue all around the circumference and let it sit overnight. Any glue is fine.

Then take a string and tie a loop at one end of the cord. I simply double up the end and tie it into a knot leaving 3″ or 4″ inches of tail. Make a noose from the loop and the string leading to the ball. Place this about 1/8″ from the end of the straw bundle, cinch the noose and start wrapping it as tight as you can without breaking the string. Remove the hose clamps as you work your way down the bundle. When you get to the other end of the bundle (about 1/8″ shy of the end), hold the string in place with a spring clamp. Soak the string wrapping with dilute hide glue and let it set until dry. You can skip this gluing step if your burnisher will be cooked in molten beeswax as the final step. Then reverse the direction of your wrapping (same rotation but now you are working back toward your starting point) to return to the starting point. When you get there, tie off the wrapping string with the tail I mentioned earlier.

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The effect of the polisher on well-prepared raw wood is readily apparent and almost instantaneous.

Soak the whole string surface with white glue or cross-linked hide glue and let it sit. Trim the straw bundle ends as needed. If your goal is to make a dry burnisher, you are done. If you want a wax-impregnated burnisher, melt some wax in an appropriate vessel and allow the wrapped bundle to soak in it until it is fully saturated. Remove the burnisher from the molten wax with appropriate caution and wipe the excess wax off. As soon as it cools to hardness it is ready to be put to work.

— Meghan B.