Tool Primer: How to Select and Use Power Drills
The first power tool I probably ever used (and owned) was a power drill. The lowly power drill can do a whole lot of things if you know how to use it. A power drill can strip paint, drill big holes, little holes, create dowel joints, sand curves and screw stuff together. It makes pocket holes and wood split. If you don’t know exactly what a power drill is, it is a handheld tool which spins a metal bit attached to an electric motor via a chuck. The magic of the drill is in the bit.
In short, it’s pretty essential to the hobbyist and homeowner. In this post, I’ll break down the types of (power) drills available for the average homeowner/hobbyist/woodshop teacher and give some tips on how to choose which is right for you.
First, let’s take a walk through history, why don’t we? A long time ago, drills looked like this:
Which, I assume, is hard on the teeth and hard on your smile and probably doesn’t get you the girls. Because what could you say? Not a danggummed thing. The girl would smile coyly at you and you’d be stuck playing with string. Once the Industrial Revolution happened, craftspeople (and according to the picture, totally masculine men who wore mechanics clothes, got grease all over themselves…and worked wood?) used a variety of metal-geared, hand powered drills. My favorite is the brace, which is pictured in this ridiculous staged photo.
Black & Decker patented the electric drill, as we know it, in 1917. Sidenote: do not take this as an endorsement for their drills today….check them out for yourself. Since then, drills have lost their cords, gained the ability to hammer and impact, bits have become interchangeable with hex bits and the world has become a more complicated place.
Why don’t we break down the different classes of drills available today?
Corded drills: Almost all handheld drills come in two chuck sizes, 3/8″ and 1/2″. The chuck size refers to the largest diameter shaft a particular drill can take. Many corded drills have a small button integrated into the trigger which changes the drills speed. A major drawback of corded drills is actually its strength. In woodworking, I usually use drills to create pilot holes and secure fasteners. I’ve found, both in my experience and the experience of teaching students how to use one, that it is very easy to strip the head of a screw (mangling the slots on in the screw on which you apply force). It takes practice and a fine touch to get right. On the plus side, corded drills are plentiful, powerful and generally cheap. They have many uses in the shop, particularly for uses that require long working times, large holes and have power source nearby. I often pick up my corded Rigid drill for three jobs: sanding and stripping, large holes with an auger bit or hole saw in wood or thin metal and long days in the shop.
Ni-Cad Cordless: Need to go outside and still need some power? Big Ni-Cad batteries do the trick. Had I written this blog post a few years ago, I would tell you that this tool is the bomb – so would all the cool tool magazines. Nowadays, I can tell you that the drawbacks of this tool outweigh a lot of its strengths for the average homeowner. This tool does two things well – it travels outside and it packs enough punch for large jobs, such as boring a 3/4″ hole through a 4×4. I have a 1/2″ Craftsman C3 driver and I used it for years. The battery’s a bit beat up with age, but I can still bust out a 3/4″ hole with a twist bit. This has become a contractor’s tool, in my opinion. Because of upgrades in battery technology, smaller drills can take care of more and more jobs. I really haven’t used this guy in about two years. The C3 line from Sears is forward-compatible with their Li-On line, so if you are in the market for a big drill, you could pick up a used C3 and upgrade to the Li-On battery. This would probably serve all your homeowner’s needs.
Li-On Cordless: This power drill is my go-to guy. It occupies the top shelf of my power tool locker and rarely gets dust on it. Not because I’m a clean woodworker, but because I use it nearly every project. Li-On cordless drills do a number of things well. They can drill small to medium holes all day long and need only one recharge. The clutch means I rarely strip out the heads of my screws, especially if I am using non-phillips or slotted heads. I can take it anywhere and it can hang in my back pocket or on a hip with no discomfort. It can’t do everything, of course, but if it can’t be done with this bad-boy, I often realize I don’t need it done that way in the first place!
Impact Drills: Impact drills use the impact of a small weight to create incredible amounts of torque on a screw or nut-head to drive the fastener into substrate. If you ever have had a flat tire and couldn’t break the nut, you can thank a mechanic with an overzealous air-driven impact drill. When I bought my Li-On impact drill, I had a revelation. I could construct nearly anything with exterior screws and never have to use a pilot hole! Or worry about the screw outlasting my drills battery again! My constructions became tighter and stronger. If I can’t do it with a regular drill, I reach for this guy. Most Li-On impact drills come with a hex chuck and only accept hex bits. This means they are made for one thing: driving fasteners hard and deep. Kicking tail and taking names. Loud as heck though. I’ve scared a number of neighbors, children and adults by randomly fastening things together without warning. You’ve been warned.
Hammer drills: The three drills above are designed to work in wood, maybe some plastics and thin metals. If you’ve got some stones, bricks or mortar sitting around that needs some holes in ’em though, you need a drill with stamina and guts. The hammer drill is the Terry Crews of the drills. He shows up in the movie to shoot a giant gun, make bug eyes and leave with a witty remark written by someone else. I’ve never used one because I don’t work in brick. But if I did, I know I’d grab a hammer drill.
With me so far? Great. Finally we get to the magic of drills, the bit itself. Over the years, I’ve bought a great number of drill bits accessories and these are my impressions.
Twist-Bit: The workhorse bit. If I said grab a drill bit, and you didn’t know what you were doing, you’d be looking for a twist bit. Twist bits cut into metal, wood and plastic with equal ineffectiveness, but are most inefficient in wood. Twist bits work pretty well in metal, although you must go slow and put down plenty of coolant. They also have a tendency to skip around the work piece, but a small divot made with a nail or punch will straighten them right up. I have a number of sets of these that I bought early in my woodshop days and I only bring them out for projects in metal or plastic. They come in all shapes and sizes and all different measuring systems. Most “99 bits and the one you need ain’t one” bit sets will have a fine selection these guys.
Brad-Point: The best wood bits. If you do any serious work in wood (and reading this blog, I assume you do, just for my sanity) get a decent set of as many different sizes as you can. Brad bits, especially in comparison to twist bits, cut clean, straight holes without the need of a starting divot.
Spade Bits – These guys get their names from the large spade-lake shape on their business end. Spade bits cut rough holes in large sizes than are attainable in brad-point or twist-bits. They have long shafts to accommodate thick material. Spade bits are cheap and work fine for what they do. They do have drawbacks. The larger the size, the more likely the bit will bind in the hole. This results in either the work piece spinning around, the drill spinning around or your wrist spinning around dangerously. So in order to drill safely while using a spade bit, make sure your work piece is clamped down, you are firmly gripping the drill and you use your body to support your wrist. And if the damn drill still tries to rip your arm off…let go and step away. A ruined work piece or a hole in the wall or busted drill is not worth a busted arm. Lastly, in order to avoid massive tear out, drill carefully until the center point of the spade bit as poked through your work piece. Flip your work around and finish the hole in the other direction, using the resultant hole as a guide.
Hole Saws – When you want a hole in thin material (think small stereo speakers or the center hole for a cajon drum) that’s too big for a spade bit, reach for a hole saw. A hole saw uses a twist bit to drill a guiding hole for a large metal drum with teeth. Instead of cutting out an entire hole, like a spade bit, it cuts only the outline of a circle. Once the circle is cut out, the center-waste sticks inside the bit. I’ve used hole saws to cut doorknobs, lighting fixtures and other circles in stuff. Same safety considerations that apply to spade bits also apply to hole saws.
Hex-bits and Shafts: Hex bits get their name from the hex shaped shaft which holds them in place. Most of these bits drive certain fasteners and there are as many fasteners as there are players on a AL playoff baseball team (too many to name but you only see the starting nine). And you always want a set of Phillips-head #2s around. Hex shafts mean smaller drills can do a lot of things with fewer bit changes. Get a baby jar and fill it up with different sizes. Some small drills only come with hex shafts. Those little guys don’t do much more than assemble and disassemble ready-to-assemble furniture or electronics but they do it well, thanks to hex-bits.
I’ll leave the “How to Use a Drill” section to SkilTools. I’m pretty sure they got a better legal team than me.
Remember to read and understand the User’s Manual that comes with any of your power tools. Wear safety glasses. If it doesn’t feel safe, it isn’t. Using tools is inherently risky business. You are your own safety inspector.
And enjoy yourself.
If you enjoyed this Tool Primer, check WoodshopCowboy out on Facebook and the other tools in the Tool Primer series:
Make it safe & keep the rubberside down this week.