Metalworking for Woodworkers
Metal is inherently strong, but it can be worked quite well with many common woodworking tools. Sometimes metal is better suited to a particular function than wood. The profile of a particular hardware component of your furniture can be much thinner than with wood. Instead of buying off-the-shelf hardware, parts can be made to suit your style. Handy tools can be made in your shop. The benefits go on.
But how does a woodworker befriend this foreign material? Without getting into the more complex world of welding, let’s take a look at some basic techniques, tips and tricks. These will be basic techniques that a woodworker could undertake with tools that are easily available or already in the wood shop. First, let’s cover some terminology.
Locked & Loaded
Angle grinders don't have a quick release. To avoid tedious and constant changing of disks, have three small angle grinders set up with a cutting disk, grinding disk, and wire brush.
A small vise on the drill press table helps control small pieces.
Inman used his horizontal mortiser and end mill bits to cut the slots on these aluminum hangers for a wall-hung cabinet. Alternatively, this type of milling can be taken to a machinist.
Touch of Magic
Furniture maker Craig Johnson made these attractive, heavyweight table-top clips for a desk from brass flat bar. The rabbets allow for wood movement and were cut on his horizontal mortiser with a carbide end mill bit (Photo by Craig Johnson).
Inman made these hinges for his shop door entrance. They allow the door to swing open a full 180 degrees, which is difficult to achieve using off-the-shelf door hinges. Materials were simple; cold-rolled tube and flat bar, with cold-rolled round for the pins that slide inside the tube. Some basic welding is required, so make friends with a welder, or delve a little deeper into metalworking.
Craig Johnson made these knife hinges for a cabinet from standard brass stock (photo by Ingeborg Suzanne).
These feet were fabricated from slices of cold-rolled round (cut by the metal supply store) threaded rod, and saddle leather. After removing the band saw marks with sandpaper, holes were drilled and tapped to accept the threaded rod, and it was welded in place. If you haven't made friends with a welder yet, epoxy would work.
There's endless possibilities for drawer pulls. They are also manageable for a beginner metalworker, in terms of size and design.
Your Dovetails Will Thank You
Everyone loves to make their own tools. Here are shop-made chisels and knife ready for action.
Common Types of Metal
Steel (hot rolled and cold rolled): alloy of iron and a small amount of carbon. Hot-rolled steel has what’s called mill scale on the surface (a rough, bluish layer), whereas cold-rolled is a cleaner, smoother, shinier surface (more like stainless steel). Hot-rolled is available in a wide variety of shapes for both solid and tube stock, more so than for cold-rolled. Hot-rolled is easier to bend but doesn’t machine as well as cold-rolled.
Stainless Steel: Alloy of steel and chromium, perfect for outdoor furniture, as chromium oxide resists rust and stains, very expensive (about five times more than steel, the last time I checked).
Aluminium: An element and most abundant metal in the earth’s crust, a good alternative to stainless for outdoor projects due to its excellent corrosion resistance, about the same price as steel, remarkably low density and very light.
Brass: Alloy of copper and zinc. Similar properties to aluminum, a little more expensive.
Bronze: Alloy of copper and tin, pricey and more difficult to source.
There’s a profusion of shapes and sizes for each of the above types, and it’s worth knowing the basic names or researching the dimensions available before ordering for a project. I find the Metal Supermarkets’ online consumer guide useful for this.
So you’ve successfully sourced a piece of stock from your local metal supply store, now what? Let’s take a look at some of the tools and methods we can use.
Metalworking creates a few new challenges compared to our woodworking environment. Furthermore, woodworking and metalworking don’t mingle well. Keep your metalworking space physically separate from your woodworking space, particularly when it comes to messy tasks like grinding and cutting. Read up on best practices, and always be aware of a potential fire hazard situation. Adequate ventilation is critical. I’ve found a covered outdoor area with a concrete slab to be a miserably cold but otherwise ideal metalwork environment. Wear cotton or wool work clothes. An inexpensive full-face visor is a must, as is good hearing protection. Metal is a real screamer.
It’s more economical, and often more practical, to source a single length of stock and then make your cuts back at the shop. Sheet stock, on the other hand, is best cut with a shear at the metal store (although sheet up to 16 gauge can be trimmed with tin snips and/or an angle grinder).
The simplest way to crosscut bar (solid) and tube (hollow) is with a metalworking chop saw (usually 14″) available from your local metalworking supply store. A 14″ abrasive disk is used for ferrous metals, and a 14″ carbide tipped blade is used for nonferrous. The saw would involve a roughly $200 cash outlay, but if you plan on cutting lots of metal, it’s a worthwhile investment. Don’t forget, as the abrasive blade wears down, you have to adjust the depth stop to achieve a full depth of cut (when you install a new blade, the depth stop is set so the blade doesn’t hit the workbench).
If you don’t intend to make many cuts, you could avoid this acquisition. Alternatives are a ‘zip’ cutting disk (thinner than a grinding disk) attached to your angle grinder for ferrous, your wood chop saw or table saw for nonferrous (carbide blade of course), or the good old hack saw. Cuts can be cleaned up with a grinder, sandpaper or hand file.
Shaping and Preparing
Any hot-rolled steel is probably a bit rusted, dull and generally unappealing. Buff it up with a 4-1/2″ angle grinder armed with a wire brush. Cold-rolled is probably coated in a gross layer of oil, as it’s part of the rolling process, but it’s easily wiped down. Use a nontoxic spray cleaner if necessary. If needed, it can then be wire brushed.
A benchtop belt sander is very handy for cleaning up the edges of those tiny pieces you’ve just cut. A small hand grinder with a 4-1/2″ abrasive wheel is equally invaluable where you need to remove material more aggressively. A small hand grinder with a cutting disk is handy for making small cuts where needed. If using the angle grinder on nonferrous, be sure the disks are marked as such. Mill bastard hand files (various shapes and aggressiveness are available) are excellent for fine tuning.
Drilling, Tapping and Bending
Step down the drill press speed, particularly for steel (use the slowest available speed), and use cutting lubricant. I always keep an aerosol can of cutting lubricant next to my drill press. Any sharp bit will do, but titanium-coated ones can’t hurt. Take some time familiarizing yourself with the mysterious world of drill bit sharpening, and figure out what works best for you. I was kindly given a Drill Doctor, which seems to work nicely, but I confess to having my share of dull bits sitting next to the drill press. I sort my various piles from the ‘completely unusable’ to the ‘desperate-in-a-pinch’. A pack of bits always makes a welcome stocking stuffer at the end of the year. A centre punch is a good idea to mark hole locations and keep the bit on track.
Tapping a hole with a thread can be a useful skill, but you’ll need an inexpensive tap set. It’s also easy to botch. The size of the pilot hole must be within a certain range. This information can be looked up on a table on the Internet, but I usually size the pilot hole so the tapered leading edge on the tap is just entering the hole. You can use a caliper to guide you. It’s also important to try to keep the tap square. Again, cutting lubricant helps.
Almost anything can be bent with a machinist vise and brute force, but heating with a plumber’s MAPP gas torch works wonders.
For milling operations with nonferrous, it’s possible to use a woodworking horizontal mortiser with an end mill bit. Alternatively, slots can be milled by a machinist on a metalwork mill. Machinists are a bit of a dying breed, but it’s worth trying to find one locally and make friends with them. My local machinist is happy to accommodate small jobs and is reasonably priced. They’re also handy for machining that requires a metalwork lathe.
A clear coat of spray paint, or alternatively paste wax, will seal the nicely cleaned steel and prevent rusting. Sealing nonferrous metals isn’t necessary. For a brushed finish on nonferrous or cold-rolled steel, put some sticky-back sandpaper on a flat surface and push the stock along the sandpaper. Steel can also be blackened, which not only protects the steel from rusting but is also attractive. Blackening is a process involving some motor oil and your trusty MAPP gas torch (the Internet has plenty of how-to’s for this). If you decide to experiment with a blackened finish, work outside and take your fire extinguisher with you.
So what kinds of things can we make with these machines and skills? Let’s take a look at some potential applications.
We have yet to see a nice off the shelf table-top clip. Making your own is usually necessary and the size and weight can be tailored to your project.
Hinges are fun to make and bring a nice finishing touch to the cabinet or full-size doors that you’ve spent time making. Knife hinges are great for certain applications, and they can be made without fancy machinery and lots of skill. Other types of hinges are also possible, and not only open the door to creating functional solutions to unique furniture challenges, but they will also allow you to use different materials to create hinges of all sorts of sizes and styles.
There don’t seem to be any off-the shelf adjustable feet that aren’t made of plastic. Plastic just won’t do. So, here’s another opportunity to elevate your piece to the next level.
For a clean, modern drawer pull, metal may be the answer. Start exploring. From clean, modern materials and lines, to something far out of left field, custom metal pulls can be the focal point of an entire piece of furniture.
Obviously, there’s always been a whole world of tool making available to the blacksmith. Without going out and investing in a forge that would take up half your shop, we can employ blacksmithing techniques to make small tools like chisels and knives. We can make useful tools that will last a long time and provide that unique pleasure in use. We can buy tool steel, or better yet. use an old needle file and shape it using the techniques we’ve covered. Then it’s a matter of tempering (using a MAPP gas torch) and quenching the steel in a jar of vegetable oil. Lee Valley offers a few books on the topic of blacksmithing, for those who’d like to delve into tool making.
Metalworking is a fun distraction from the seriousness of woodworking. Hardware is an important part of your piece, and so during your next project design, consider making your own. Environmentally, high recycled content is the norm for steel. According to greenbuilding.com, this can range from almost 30% to just over 70%, and it can be infinitely recycled, so perhaps there’s room for more metal in our furniture. The inherent strength of metal can also lend longevity to your piece of furniture. Get creative. Be warned, however – metalworking is highly addictive and might start cutting into your woodworking time.