Metal Wire Inlay Part Three



Finally we are at the heart of the matter, actually executing your design, cutting into your stock and creating a metal wire inlay.  You should have the tools and a design by now if not, get them, it’s time to get to work.


Draw or transfer your design onto your stock however you like, freehand, tracing paper, it really does not matter. Prepare your wire for inlay by cutting it to length, filing a profile if necessary and roughing up or scoring the sides. Once your wire is prepared you will then cut into the stock to create a mortice along your layout lines using a knife and stabbing tools. Do only one line at a time. Once a mortice is completely cut along your line you will embed your wire into the stock using a hammer and a punch.  When your wire is almost completely embedded in the stock, wet the stock surrounding the wire slightly so that the wood swells up around your wire. Continue preparing, cutting, hammering and wetting until your inlay is complete.  Once your inlay is complete you can file of the protruding wire flush or very nearly flush to the surface of the wood.


That is it, in a nutshell. It does not get more exciting than that.  Not to say there are some nuances & best practices to follow or at least be aware of, so let’s cover each step in detail.


Cutting in

Just to remind you, the most important principal to remember is that; we are NOT removing any wood from the mortice, we are just pushing the sides away from the center so that when the wire is inserted (bashed in with a hammer) and moistened it will swell back up and hold the wire securely with just friction. Use your knife to lightly score the surface of the wood along your layout line, does not have to be deep, 0.010” or so, be cautious to keep it even and smooth as this cut will be used to align your stabbing tools and help keep your wire bends smooth. Score one line at a time and only do it once, following up with a second knife cut will generally shave some material away – which we do not want. Once your line is scored use your stabbing tools to finish that cut to final depth. Take one of the stabbing tools place it in the cut you have made and push it straight down, softer woods you can generally push the tool into, harder woods you may have to tap it in with a hammer. Drive the tool in to about the same depth as the width of your wire (0.050” wide wire, drive down about 0.040”) exact depth is not critical, just so long as the depth will let you inlet the wire by at least like 80/90% of it’s width. If you cut too deep and drive your wire flush with the surface of the wood, you won’t be able to file it.


Make sure your tool is perpendicular to the surface of the wood


It is critical that your tool is perpendicular to the surface of the wood and is driven straight down. If you were to drive the tool at an angle left or right of the mortice your wire will set in at an angle as well and tend to roll over when you tap it in. When you withdraw the tool from the cut it will take a bit of force, the wood will have swollen around it already, do not worry it back and forth or you may snap the tip – pull it straight out. Now you know just how tightly that wire gets held in there! If you do break a tool off and you can’t get a grasp on any protruding bits (forceps are handy here) DO NOT try to dig it out. Just take another tool and drive it all the way in, make another tool and keep going.


Continue stabbing in until the mortice is complete, it helps greatly to overlap your stabbing cuts slightly, your lines will also be smoother. Begin using progressively narrower and narrower tools as you approach curves, if you have made curved stabbing tools, use the appropriate one for the curvature of the line. When you start exiting a curve, start using progressively wider stabbing tools. If you are using square stabbing tools the mortice in tight curls and volutes may look a little “jaggy” – don’t worry about that if you have scored the surface the jaggedness will disappear when the wood is moistened. There are a couple of other options to the scoring step. You can use your carving gouges to lay out the lines, keep in mind that the gouges are WAY thicker than your wire material, so do not press too firmly – just score the surface. One benefit of this method is that you can design your curves to match the sweeps of your gouges and run nearly perfect lines. You can also completely omit the scoring step altogether. It is more difficult to achieve a smooth line with no jaggedness, but with practice it can be done. Overlapping your cuts in this case is absolutely necessary. Now that you have cut your first mortice you have somewhere between 10 minutes and an hour to get your wire embedded before the wood fibres start to naturally swell up and close the mortice. If that happens just gently use your stabbing tool to open it up again. Don’t cut, just push the fibres apart.


Preparing the wire

The wire will be held in the mortice by friction, not to say we can’t help that along a little bit by scoring the sides of your wire. By scoring we are raising little burrs that provide a little more surface area for the wood to “grab” onto. You can score the entire spool of wire before you begin or little lengths as you go. To score your wire, grab 2 files, place your wire between the files, perpendicular to the length of the file then hold the files together firmly and pull (pliers are useful here), several times if necessary until you can see lines scored on both sides of the wire. You can also (and I prefer to) place a fine round file in a vise and use 2 pairs of pliers to drag the wire across the file (both sides, perpendicular to the files length). Now measure and cut your wire to length. The easiest method is to lay your wire along the mortice and snip it where the mortice ends. Sharp flush cutters will be required to do that, otherwise you will have to lay out the wire, mark it and then cut it. I would recommend slightly longer so that you can measure twice and trim it. It can be helpful to cut the ends of your wire at a (very) slight angle so the top is wider than the bottom, this can aid in getting tight joints. If you are inlaying into a tight curve or curl you probably want to pre-bend your wire to that shape as closely as possible. Pre-bending makes insetting the wire easier, especially over convex/concave surfaces. Pre-bending also ensures a smooth curve free of jags – if you have a kink or jag in your wire your wood will not smooth it out, your wire must be completely free of kinks and jags. That being said, you can bend the wire “as you go” tapping in the wire slowly and basically just guiding it into the mortice and that IS the way to go for long relatively straight runs, but it becomes more difficult in tight curves as the wire will want to spring out.



Insetting the wire

To inset your wire, lay it in the mortice, you may find that you can start it in just by pressing it in with your fingers (not always though). Start at one end and tap it lightly with a small hammer until the wood starts to grab the wire. Continue tapping along the length of the wire (lightly) until the whole wire is embedded to about half of it’s width, then tap along it’s length again setting it deeper into the wood. I find switching to a brass punch at this point helps avoid denting your stock with the hammer. Keep tapping along it’s length until the wire is almost completely set into the wood. Do not tap it flush with the wood or else you won’t be able to file it. Some people also like to leave the wire somewhat proud of the wood so that it can be cleaned later on. While insetting your wire, at some point you are bound to have it “roll over” on you, that is where the top of the wire bends off to the right or left as the bottom goes straight down. DO NOT try to bash it in thinking the wood will straighten it out (it’s won’t refer to the heart on the lock panel of the banner image – that is an example of not properly dealing with a roll over) it will simply roll over further and embed itself into your stock and leave a wide spot in your inlay after filing. Instead, use a burnishing tool to try to bend the rollover straight up again, tap VERY gently and hope it doesn’t roll over again. If it does, you may have to pull out the whole wire and start again. You can also use a piece of shim stock held against the side of the wire where it is rolling to support that side while tapping. If you still wind up with a roll, consider trying to turn it into a design feature rather than pulling the wire, as pulling the wire has a good chance of pulling some wood out with it and you will only be able to “redo” a line once or twice at the most. After that you will have to adjust your design to use a thicker wire at that point.




This step is short and sweet and nearly impossible to screw up! Once your wire is inset into the wood moisten the wood on either side of the wire, it will swell up and grab the wire, if there were any minor little overcuts and jags in your wood, they should disappear as well. Just a drop or two of water on your finger is enough, saliva works as well. If the mortice does not close up completely add more moisture. If it still does not close up you may have to “add features” to your design. Adding another wire close to and parallel to the mortice that won’t close up will force more material (wood) towards the first mortice and hopefully enough so that it closes up. Whatever you do, don’t try to fix a design that has been moistened until after it has COMPLETELY dried or else it won’t swell back up again.



Filing off

once your design is complete and all wires are inlaid you can file off the excess. What is “excess” is debateable. Some people feel that inlay should be proud of the wood so that it can be cleaned – which is good advice if you are using an inlay material that tarnishes or corrodes. If you choose to leave your wire proud of the wood, you will not be able to file it at all or else you will get burrs along the top. In this case you must pay particular attention to tapping the wire in so that it is all at a uniform depth and that you have not deformed the top of the wire by tapping too hard. Inlay that stands proud of the stock does have a very nice look and tactile feel to it – if very difficult to execute. If you are not one of those people you may choose to file the inlay flush with the surface of your stock. This presents other challenges most significantly, burrs, filing metal will cause a burr, you can wind up embedding that burr in your stock leaving a ragged looking line unless you are (very) careful. Use very fine files (Swiss cut are best) and file equally in both directions, alternate one cut from the left then one from the right, cutting lightly. Draw file along a line when you can. If you see a burr starting to rise – get rid of it immediately. Filing flush will also embed metal chips in your stock, the finer the file, the finer the chips – you want very fine chips as they are easier to remove with the super-secret secondary purpose of the eraser. That drafting eraser (natural rubber) will pull filing dust right out of the stock just like erasing a pencil line, if the chips are too large, it won’t work so well. This trick is also handy while filing other types of inlay, dissimilar woods and pewter pouring’s. The key to success is to NOT let the chips build up, if you see them starting to form up, brush or blow the bulk off then use the eraser. File and repeat until done.



Wide wire – cutting mortices.

I stated that we are not to remove material from the mortice. That is not entirely true, there are (rare) situations where material will have to be removed. In the case of a very wide wire (0.030” or more) your wire will more likely pop out than be held by the wood. In this case you can cut another mortice parallel to the first and remove the wood between them, keeping in mind that the mortice still needs to be slightly narrower than the thickness of your wire. In some cases you may actually want to use a pin or even glue if the wire is too thick.




Your design will undoubtably be made up of many intersecting, and branching lines. Even the smallest gap where a line intersects or branches is going to be obvious. Where a wire intersects or appears to be ‘crossing over’ another wire, cut your mortice right up to the side of the wire that is to be crossed then determine the angle at which your second wire intersects the first. File the end of that wire to that angle so it buts up against the first wire with no gaps. Hold it firmly against the first wire while tapping it in. This leads up to another rule I told you not to break, cutting one line at a time. In the case where lines intersect it looks terrible if one of them is out of alignment with itself, that is to say, stops on one side of the intersecting line and continues out of alignment on the other side. To eliminate that problem, while scoring your lines also score the intersections, don’t cut them to depth, just score them (because you won’t be able to after a wire is inlaid) that will leave you with an exact benchmark where one line intersects another. Another joint you will be doing is a branch, where one line splits out of another smoothly. To achieve this cut your second mortice right up to the first and slightly widen the first mortice where your branch begins. To prepare your wire you will need to taper the end of it (the thickness) to almost nothing, I find placing the wire on a rounded block of wood and filing along it’s length does this nicely. Slide the tapered end of the wire up alongside the wire it branches from into the widened side of the mortice, that mortice should be widened just enough to slide the taper in easily as you will roll it over by hitting it with a hammer. Tap in the rest of the branch normally, when you moisten the wire the branch joint should tighten right up and be invisible. Incidentally you may want to use the tapering trick to vary the thickness of a wire along it’s length or so that a wire terminates in a point rather than a flat end.



Concave & convex curves

As noted, curves can cause problems with wire wanting to “spring out” of it’s mortice, on gentle curves it is generally not much of an issue, but on moderate to severe curves you may want to employ a couple of little tricks. Over a concave curve the top of a wire is being compressed along it’s length making the wire want to pop out in the middle. To fix that we can make the bottom of the wire longer than the top easing that compression (somewhat). Cut a series of vee notches along the bottom edge of the wire to about halfway through the width. The number, spacing and width of the notches being dictated by the amount of curvature. No, this isn’t really making the wire longer, but it is removing material from the width of the wire making it more susceptible to a bend across it’s width. Careful when cutting the notches, if you cut too close to the top edge it will just kink. On a convex curve, the wire is being compressed along its bottom edge making the ends want to spring out – cutting vee notches along the bottom does the same thing as in a concave curve it is just removing material from the wire so that it can bend into itself.


Overall, the best strategy is to create a design that
avoids severe curves wherever possible.



Dots are fun, quick and easy, you can use round, oval, (or round wire set in at an angle to appear oval) square, triangular – whatever cross section of wire you like. The method is nearly the same as inletting a wire. Cut your wire square on top, then cut it off the spool at an angle so that is has a sharp point on one end, basically make a headless nail, it does not need to be long under 3/8” is just fine. Trim that sharp end so that it is symmetrical(ish) other wise it will want to drive in at an angle. Take a drill just slightly smaller than the wire and drill the location in the stock where the “nail” will go, not quite to the full depth, say ¼” for a 3/8” “nail”. Clear the chips from the hole, hammer your nail is almost flush moisten and file as you would a wire.



In Summary

That is about the size of it, wire inlay is one of the simpler embellishments to execute and takes a minimum of tools. Of course a well thought out attractive design, practise and experience play an important role in successful execution.

I am not an authority on wire inlay methods or techniques, I am sure there are other methods and other theories about how to execute a design. I would be happy to hear your thoughts and comments, just reach out on the contact page or find me on Facebook.