Inlay: There’s a Place for Both Hand and Power Tools:
A rotary tool plunge base is a useful addition to the traditional kit, as Brian Greene discovers
I first met Garrett Hack 15 years ago and saw the exquisite inlay he is known for and watched him work small, simple, usually homemade hand tools with great precision. I said to myself then and there that one day I wanted to be good enough as a furniture maker to be able to do that sort of work. Both the decorative effect of inlay and the means of making it appealed to me.
I’m nowhere close to Garrett’s skill level and never will be, but I have added basic inlay to my repertoire of skills and use it whenever I can. I’ve had the pleasure of doing two short seminars with Garrett to learn basic inlay techniques. The essential skills are not all that difficult. The real challenge is in the level of patient precision this sort of work demands. This article will help you get started. I’ll show you some basic techniques and the tools required for hand work. I’ll also explain when a router may be helpful. In that regard I’ll feature the rotary tool plunge base from Veritas Tools.
Inlay has a long and rich history. The technique of metal-in-metal inlay was perfected in ancient China, as shown in examples of vessels decorated with precious metals from 400–220 BC. The ancient Egyptians were inlaying precision wood, metal and stones 3000 years ago.
Inlay was a popular form of surface decoration during what could be called the more expressive periods of furniture styling (aestheticism) in North America and Europe. Early furniture makers used inlay to outline and highlight parts of their furniture. Not a bad idea when dim room lighting was the norm. In addition to pure decoration, inlay emphasised the horizontal lines of a table apron or the verticality of a leg. Federal furniture from the USA is well known as is 18th-century British and European neoclassical. Arts and Crafts styles used it very simply. Art nouveau and art deco (think Ruhlmann) artists took it to new levels. Inlay may not be as popular as it was at its peak but excellent modern examples show up in the work of both period furniture makers as well as in contemporary work. Garrett Hack and Steve Latta in America have unique approaches and Andrew Crawford in Great Britain is an excellent contemporary maker using inlay to high levels of skill and aesthetic effect. Most of us may never take our work to such high levels but inlay still offers opportunities to embellish your own work and can be a useful set of skills for those times when you may be required to execute a bit of repair.
Inlaid surface decoration usually takes the form of stringing, line and berry, solid surface inlay and edge banding. The square pegs on Greene and Greene furniture could be included here. It does not include intarsia, marquetry or parquetry. Given its adjacency to surface decoration, it is also useful to have facility with a variety of edge details such as chamfers, worked beads, applied beads, round overs, routed or planed profiles. We’ll save discussion of those elements for a future article.
The simplest forms of inlays – strings terminating in berries (circles) or small squares – require the most basic of tools and techniques and is a good place to start honing your skills.
The easiest way to start creating inlay – let’s say a basic bit of string and berry detail – involves just three specialised tools. You need a scratch stock, either shop or commercially made, with a cutter; a small chisel the same size as the groove into which you will be putting the string; and a small plug cutter or a dowel forming block.
You can purchase micro chisels from Lee Valley Tools made by Veritas in sizes .04in, .032in and .025. These are made to match the sizes of cutters in their inlay system.
You can also make your own cutters to match these chisels to suit the style of scratch stock you prefer. Most of the other things you will need you probably already have – a block plane, lightweight hammer, bench hook and a scraper. A shop knife is also useful.
Generally, you will want to be inlaying strong contrasting colours. Black and white works with everything but you can certainly use other colours. A good example is a cherry (Prunus spp.) drawer front
with a string border of holly (Ilex spp.) (or aspen) as a light colour that is the closest to white, punctuated at the corners with little contrasting squares or circles. Very light maple (Acer saccharum) makes a good substitute but it will darken in time. Holly is less likely to do so. The logical accompaniment to white is black and you can use African blackwood (Dalbergia melanoxylon) or ebony (Diospyros spp.) for that purpose.
The other important item isn’t a tool, it’s a practice board. A scrap of cherry or mahogany (Khaya ivorensis) works fine. Here you can try out techniques and patterns and develop skill through experience.
The part into which you will be installing the inlay will be completed and have been smooth plane finished. Do the layout of your choice with a light touch with a soft pencil. I like a little white space between my lines and berries or squares.
I start by getting my materials ready. I rip my inlay material slightly oversize from a suitably wide piece of stock at either the bandsaw or the table saw. Re-joint the edge between cuts. Make enough string stock for your immediate needs and a bit more. I then run it through the thickness planer and bring it down to just slightly fatter than the groove size you will be making, say about 1⁄16in thicker. Later you will bring it to final size and shape with a block plane.
After you’ve been doing this for a while, you’ll have a stock pile of stuff. As to the size of the string inlay, there are no rules. Generally, smaller work suggests thinner lines; bigger work, thicker lines. Use the
work of others as your guide and you won’t go wrong. Berries are easy to make from a scrap of stock and the plug cutter at the drill press. I use the Veritas snug plug cutters because they make a slightly tapered plug that makes a perfect fit in a drilled hole. The only way I know to make plugs smaller than 3⁄16in is to use a dowel plate. The ones I’ve seen go to 1⁄8in. Squares are easily made with the hollow chisel portion from a mortising drill set or with a square hole punch, also available from Lee Valley.
Let’s get on to the main event. To make grooves you need a suitably sized cutter and a means of holding it. I’ve tried a few ways and I like the traditional scratch stock such as the one made by Garrett Hack or the original Veritas beading tool. They are both easy to hold and easy to use. In my classes with Garrett he taught us how to file our own cutters with a piece of scraper or saw plate and a couple of files. It’s easy to do. You can also purchase ready made cutters in various profiles as well as blanks.
Various types of scratch stocks are available
To make the groove for the stringing start by scratching the cutter along the surface at an angle to get started. Keep repeating and increasing the angle until the cutter has reached the desired depth (a 1⁄8in is fine). Be careful to keep the fence of the scratch stock or beader pressed against the edge. Find a comfortable way to hold the work. Pressing the work comfortably against a bench dog or securing it in a
vice both work for me.
Here, folks may be wondering that this operation is tailor made for the router. The answer is ‘yes’ and ‘no’. The problem is that the router, whether large or small, is spinning at a blistering speed. It makes the work go faster and that’s both a blessing and a curse. The slightest jiggle will ruin the work. This is compounded with small strings. Some might think that the risk is too great. However, I think it could be very useful for larger inlays, say 3⁄16in+. The new plunge base designed by Veritas for rotary tools offers a lot of potential here, not so much because it takes away the speed problem but because it’s a smaller tool that is easier to control. A small router and a small plunge base will also be less overwhelming when the work pieces are small. In most inlay patterns you will make several different kinds of string lines. Stopped, as we are doing here; mitred to turn a corner; and, crossing one over another. Curves are another matter again, warranting a separate article.
For the pattern shown here, you should terminate the string groove with a vertical cut with the chisel. Level the bottom of the groove where it meets the vertical cut with the bevel of the chisel down so the stringing will fit tightly and accurately. Total consistency as to the depth of the groove is unnecessary. Close works;
ensure there are no bumps.
Shaping the string
Now let’s turn our attention to shaping a piece of the string material to fit the groove. You will always work with material that is oversize in width. While this seems wasteful, it really isn’t considering the efficiency gained from ease of handling. You’ll see what I mean as you try it yourself. Along one edge of the strip of stringing you want to form a taper so that the string becomes wedge shaped. This is easily done by running one side of the block plane off the edge of the inlay material, automatically creating the taper. One or two passes with a finely set sharp blade is enough.
The logic behind the wedgie, as I was taught, is both brilliant and simple. The wedging action means that you do not have to fret about making the string a precise width. As long as you are close it will work. The wedging action self-tightens the string as it’s pressed home. The process ensures consistency. If you overdo it with the block plane and the piece bottoms out because it’s too thin, it’s a simple matter to remove material from the edge so that it effectively becomes thicker. Having that extra width of material helps.
You will know when the size and shape of the string is right by how it feels when its inserted a little bit and you attempt to lift the work piece. Try in several places.
Setting the string
Satisfied that the string will fit, cut it to length with a sharp chisel on the bench hook. If it’s a long piece it’s OK to do it in two or three lengths. Inlay with the grain does not introduce any wood movement issues. That’s not the case when you are inlaying a string across the grain. Seasonal shrinkage or swelling of the wood can cause gaps or popping. There are several solutions. The easiest is to design the pattern so there are no long lengths (more than 3–4in), interrupting the pattern with negative space or berries, squares or a solid form. Another way is to use shorter pieces butted together and make the piece when the wood is as dry as possible. Future repairs will be minimised but easier to do.
I use PVA glue diluted about 10% with water. This increases the open time a bit and enables the glue to flow into the groove more accurately. Use a syringe or toothpick. Start at one end and put the inlay tightly into the end of the groove. Proceed along the length of the groove, pressing it in firmly as you go. When the string is in, immediately tap it down snugly with a light hammer. With either a knife or block plane cut down the excess to about 3/16in or thereabouts. Using a suitable burnishing device (the head of the hammer works), rub the string firmly to mush it out and press it well into the groove. Set aside to let the glue dry. When dry, the string can be planed or scraped flush with the surface. Don’t sand especially if you are inlaying with holly and ebony. The black sanding dust will bleed into the holly and the stains will be difficult to remove.
Repairing mistakes is not too difficult. If you get to the end of the run of string and find yourself short, cut the end square and inlay a short piece to fill the gap. When cutting down the oversize it’s possible the string will crack below the surface. No worries. Just cut the ends of that section square, scratch out the string and inlay a new piece.
Larger inlays and bandings
Diamonds, squares and circles or unique patterns are all possible. Start with a pattern. Mark out the recess from the pattern carefully with a knife. Back cut with a chisel from the waste side. For larger recesses, use a router to remove most of the waste. The smaller rotary type tool and the new plunge base from Veritas are especially useful for this work and less intimidating. Finish with a chisel using the flat routed surface to register.
Make the part to be inlaid from the pattern a little thicker than the recess. Something between 1⁄8 and 1⁄4in works well. Bandsaw to rough size and plane to fit the space. Under-cut slightly, letting that wedging action work for you as it did with the stinging. Plane carefully to size, checking frequently. Add glue and tap into position. Burnish it down and allow to dry. Plane flush with the surrounding surface.
So much of what makes the work of Garrett Hack, Steve Latta and others pop is not just the precision of their execution, which is really amazing, but their overall sense of design and proportion. What you see is years/decades’ worth of experience. Don’t be humbled. Start small and be patient. Think of every project as
a new learning opportunity.
Copy the aspects of the masters you like. Eventually, with patience and practice, you’ll develop your own ‘voice’ and ‘vocabulary’.