Metal Wire Inlay Part Two
Fortunately, inlaying wire into a gun stock or other piece of wood take relatively few inexpensive tools and a minimum of space, just enough for you to hold you and your work comfortably, comfortably meaning good lighting and a good chair, because you are going to be there a while!
Most of the tools you need can be bought and you probably have laying about the house anyway a few do not actually exist commercially, so you will have to make them.
Let’s just dive right in:
One or two full size fine files, a swiss cut is best, a mill smooth file will do. Bastard and rasps are too coarse. You may also want a small selection of needle files for finishing and fine work.
A fine chip carving knife with a sharp fine point for scribing in your design. The point should be very acute to be able to cut around tight curves. An Ex-acto knife will also work though generally have very fine points, fortunately there are a myriad of blade geometries to choose from so you should be able to find one that is a little more stout.
The pencil should be obvious, as is the eraser, but the eraser has a secondary purpose – drawing filings out of your work. (More on that later)
A high quality flush cutter is the best choice & will be the most expensive tool (a nice Xuron will be about $30CDN. Buy one, you will thank me) You want accuracy when trimming your wire, scissors will work, but will not be as accurate as a set of flush cutters. Also scissors will get nicked pretty quickly if you are cutting thick or German silver wire.
These you are going to make from scratch or from an existing tool. Many people grind and file Ex-acto knives to shape. You can make a stabbing tool from nearly any fine knife so long as the thickness of the point is not too much thicker than the wire you will be working with. I made mine from 1/8” O1 steel rod filed and ground to shape.
Another great source would be scalpel blades, these are already available in useful geometries and tougher materials.
You will need a small hammer, a chasing hammer works nicely, I also use a small 4oz. tack hammer. It definitely helps to polish the heads to prevent slipping and denting your work.
Brass punches are strongly recommended again, to aid in not putting dents in your stock after smacking it with a hammer.
If you are going to use round wire (or other geometric profiles) you are going to need a set of small drills (slightly smaller than the diameter of your wire) and collets to hold them.
Forceps are handy for handling and holding small pieces of wire – especially when tapping them into the mortices. (especially if you have big fat fingers like me!)
Some of us can get away without vision aids, sadly, others cannot.
Stabbing Tool Geometry
Your primary tools are going to be your stabbing tools, so don’t skimp or take shortcuts when making them (because you can’t buy them). The key thing to remember here is that you are not removing any material from the mortice that your wire will lie in, you are just “pushing” the wood fibers to the sides of the mortice so that you end up with a vee shaped channel. A dull tool will crush and push the fibres into the bottom of the mortice effectively “removing material” again we are NOT removing material from the mortice. Sharp is the word of the day, your stabbing tools (small chisels actually) must be sharp-sharp-sharp and you must be prepared to resharpen them periodically.
The shape of your stabbing tool(s) is basically a very small double beveled chisel. It should be slightly longer than your wire is wide say +20/30% and slightly thicker than your wire, again +20/30%. If your tool is much thicker than your wire, you will have problems getting the wood to swell up around the wire. If your tool is too thin, you won’t be able to set the wire in the mortice. The width of your tools will vary, wider tools (up to 0.250”) are useful for longer straight lines while progressively narrower tools (down to 0.020”) are to be used to stab into curves and corners. That being said, you can make tools that will handle several different thicknesses of wire, my tools are about 0.020” thick and work just fine with wire thicknesses between 0.008” to 0.180”. I find 0.005” wire to be a little loose in the mortices my tools cut. You can make your stabbing tools either flat like a chisel or concave like a gouge, a selection of both is handy, but as the width of the tool gets narrower, having a curve to it becomes less useful. Curved chisels will help you get a smoother line but is not the only factor considered while trying to achieve a smooth line. (more on that later)
Point geometry can be squared off like a chisel, partially rounded or spear shaped. Spear shapes are particularly useful getting into tight curves, but cuts need to be spaced closer together than square or rounded. Spear and rounded shapes are also (obviously) easier to stab into hard woods. What you can make stabbing chisels from is pretty much up to you, hacksaw blades and Ex-acto knives are popular and cheap choices. I personally find Ex-acto knives to be too brittle and hacksaw blades to be too thick (in most cases). I’ve made mine from 1/8” O1 tool steel rods hardened and annealed. Each is about 2.5” long and ground to shape. So far (knock on wood) I have only managed to break one of them off in a design. Another excellent source would be scalpel blades, much tougher than Ex-acto knife blades, less likely to break and will stay sharper longer. (assuming you buy quality blades and not the Amazon daily special!)
I am not going to go into design very deeply at all, it’s your design, your gun, do as you please. All I really have to say about designing a wire inlay piece is:
Use a pencil, have a plan! Layout your design first and make sure you like it, make sure you like how it contrasts, compliments and/or emphasises other features such as overall architecture and carvings. If not, that is “use 1” for the eraser. Start on paper, draw right on the stock, whatever you like best, just be sure before you start cutting.
Design within the limits of your materials. Keep in mind the nature of the material you are cutting into, where you are cutting and the curvature of the surface you are cutting. Creating two mortices too close together and then hammering a couple pieces of wire into them is going to put a good deal of pressure on the material between the mortices, that material is going to want to chip out, PARTICULARLY if your mortices run perpendicular to the grain direction you end up with short fibres between your wire that will naturally want to chip away.
Pay attention to grain direction when creating your design
Similarly while creating a very small or tight curl or volute you can have the same situation, some of the grain in the curl will wind up being very short – particularly in the “eye” of the curl. Your best bet to avoid these situations are sharp tools, planning and a bit of practise.
Watch the curves! Especially the compound ones. Inlaying a wire is fairly easy on a flat piece of wood, but gunstocks have very few flat spots, 90% of what you do will be on a concave, convex or compounded surface. The wire you will be using likes to bend easily across it’s thickness but becomes much more difficult to bend across it’s width (there is a trick for that later). wire inlaid in a convex curve will want to spring out at the ends and it will be longer along the top than along the bottom, in a concave surface the wire will want to spring out in the middle and be longer along the bottom than the top. To combat this you can use softer wire or anneal the wire you have (not normally recommended), alter your design so the wire is not under so much stress or avoids the curved feature, use shorter lengths of wire or create an “anchoring feature” in the design. Imagine you want an inlay that runs from one side of the fore end to the other perpendicular to the barrel, that wire has very little chance of staying put unless you bend it along it’s length (discussed later) or by adding a bend, swirl or curve at each end of it (either side of the stock) that will give the ends of your wire much more surface area to hold on to (there’s that friction thing again) and much less probability of springing out. Though if you can avoid a straight line across a severe curve, all the better.