Here's a simple woodworking project which you can make fairly quickly and with only basic hand tools and skills. The wood I used was a simple pine bed pallet which was left out on the side of the road for trash pickup.
As a hand tools woodworker with limited skills (or is it unlimited laziness?) in taking rough wood and making it smooth and flat, I liked the idea of starting with wood that was already mostly ready.
So let's get started!
Step 1: Choose the Boards
First, remove any nails or staples from the boards. Then lay them out side by side and figure out which ones would look nice together. I used three boards for the top and four boards for the sides, because the sides need to be wider at the base.
Once you're happy with the layout, glue the top boards (for the seat) together along the long edges. Then do the same with the side boards. You will probably need to smooth the edges first with either a planer (power tool), hand plane (hand tool), or sandpaper (no tool).
Choose your preferred method for attaching the top to the sides. I used dovetail joinery, because I love the look of dovetails. But you could use many other methods as well. The second picture shows how I began with the dovetail joinery, marking the board widths onto the joining board. Please see here, here, or here for some Instructables on how to do dovetail joints! Do not glue the top and sides together yet.
After dry-fitting the pieces together, trim the sides so that they are flush with the seat at the top and then curve gently outward to the bottom. You can also create a little hollow in the bottom center of the side boards, so it has two legs on each side. I used a coping saw for both of those tasks. See the finished photos to see how I shaped the sides.
Step 2: Make the Tenon and Mortise
A crosspiece is really helpful to make the stool more sturdy. For this bench, I used another piece of the pallet wood. To fit the crosspiece into the sides, mortise and tenon joinery is the way to go. Let's start with the tenon.
A tenon needs to be narrower on at least two, if not all four, sides of the piece, leaving "shoulders" which butt up against the other board. You can see in the first picture that my tenon is approximately half of the width and height of the board. The most important thing is that the shoulders are square to the piece, and the four sides of the tenon are square to the shoulders. Also, I think it's a good idea to make the tenon longer than necessary (see the last picture in this step). You can trim off the excess later.
Use the tenon to mark where you will make the mortise. Once your lines are drawn, grab your chisel (which is ideally the exact width of your tenon). Place the chisel a little bit away from the end line, with the bevel facing towards the middle of the mortise. With the chisel perpendicular to the board, strike the chisel firmly. Now move the chisel slightly closer towards the middle, again with the bevel in. Do it again. Go about halfway, then start at the other end and work towards the middle. Always keep the bevel facing the center.
Once you've made one pass, use the chisel to lever out the waste and keep going. After you've gone about halfway through the board, flip it over and start on the other side. Eventually you will break through, and then you can clean up the four walls. Now your tenon should fit! If not, pare the tenon very slowly until it fits.
Lastly, we need to open up the outside of the mortise slightly, to accomodate the wedges we'll make in the next step. Using your chisel, slightly slope the outer walls of the mortise on the top and bottom (the short ends). I would create enough of a slope that the height of the mortise on the outide is perhaps 1/8" wider on the top and bottom than on the inside (which should just accomodate the tenon).
Step 3: Make and Shape the Support Piece
As I mentioned, the support piece is a simple piece of pallet wood. However, I wanted it to have a nice little inward curve on the top and bottom. To shape the piece using hand tools, I used this simple trick:
Draw the line of your desired curve on both sides of the board (a template might be handy). Then make straight cuts down to the line, from one end of the curve to the other. You can make as many cuts as you want; in fact, the more cuts, the easier your next step will be.
Once you are done, take your chisel and mallet. With the bevel side down, and the chisel tip pointed at the bottom of the next kerf, strike the chisel with the mallet to drive the chisel forward. Keep on doing this until you get to the halfway point, always keeping the chisel tip pointed at the bottom of the next kerf. Once you reach the halfway point, start at the other end and do it again.
Now you have something like in the second picture. If you have a drawknife, this would be a good time to use it to smooth out the curve. Otherwise, you could use a rasp or sandpaper to do it. Repeat on the other side of the board, if you want the curve on both top and bottom.
Step 4: Preparing for Double-Wedged Tenons
I am a huge fan of wedged tenons. They look beautiful and add a lot of strength to your joint. Wedged tenons are the perfect choice for joining the support piece to the legs. Double-wedged tenons are even better! I followed woodworker Ian Kirby's advice which you can read here (scroll down to Figure 4 on page 55), but I'll explain it here too.
First you cut the kerfs in your tenon. Cut them no more than 1/4" from the top and bottom of the tenon, and stop your cut about 1/8" from the base.
Next, cut your wedges. The wedges should follow more or less a 1:8 gradient, and they should be about 1/3 longer than the saw kerf in the tenon. As you can see, I used scrap wood for my wedge. Choose a wood that is a noticeably different color than the tenon! The contrast is part of the appeal of wedged tenons.
Step 5: Final Assembly
Once you're ready, it's time to assemble all of the pieces. This is a nerve-wracking moment, because you are joining all of the pieces of the stool at the same time! And with wedged tenons there is no turning back.
First, glue your dovetail joints, the shoulders of the tenon, and the tenon itself. Assemble the dovetails, and at the same time work the cross piece into the mortises on both sides. Check for square, and get your wedges ready.
Set your stool on one end (you'll need to create a recess because you have a tenon sticking out both ends). Apply glue to both sides of your wedges and drive them into the kerfs of your tenon with a mallet. You want the perpendicular face of the wedges on the inside, with the angled part on the outside. The wedges will splay the tenon outward until it meets the outside walls of the mortise. Alternate hits on each wedge, so they both go in about the same amount.
Now repeat the steps in the preceding paragraph for the wedged tenon on the other side.
And guess what? You're done!
Step 6: Finish!
Your stool is done, but it's not finished. Haha, a little woodworking humor for ya. On the house.
Lastly, do your final planing and sanding and apply the finish of your choice. My preference is a 1:1:1 mix of boiled linseed oil, varnish and mineral spirits.
This is potentially a very quick and easy project, depending on the tools available to you and how you join the pieces together. I made this stool 9 years ago and expect it to last another 90. Let me know how it works for you! :)