The tools I use to build rustic furniture are essentially hand tools. The non cutting tools are made of wood and I do them myself.
Of course, with some dexterity and courage, you can build many kinds of furniture with only an axe, but here is a list of the tools I consider essential:
one or more axe, a knife, a mallet, a sledgehammer or maul, steel and wooden wedges, hand drill and bits, auger bits.
And useful tools:
drawknife, chisels and a plane.
The maul is basically a wooden sledgehammer. It is built in the same way as a mallet, so these instructions are valid for both, simply adjust the dimensions given.
First, select a piece of log about 15-20 cm in diameter from a hard wood, difficult to split, such as elm, beech, yew, apple or pear.
Drill the maul head perpendicularly to the log, at a diameter over 35 mm, otherwise the maul won’t last very long.
The next step is to choose a handle. It can be a simple branch, but the best method is to cleave an ash or beech log of larger diameter, so as to avoid the pith of the wood. The final diameter should be about 4 cm, and the length around 1 m. If you use cleft wood, round it of carefully, otherwise it will be rather uncomfortable to use... One end of the handle is whittled to the diameter of the hole, first using an axe, then the knife, so that in fits tighly all the way through the head. Next, cut a slot in the end of the handle about 5-10 cm deep to enable you to drive in a wedge. Make the wedge following the instructions in this article
Insert the handle in the head, and drive in the wedge from the other end. They are then locked solidly together.
One last thing before you can use your new maul: Slightly chamfer the ends of the head, it will help it resist splitting.
This kind of club is very easy to carve. You need a piece o log 15 to 20 cm in diameter and about 30 to 40 cm long, in one of the species used for the maul head, even though this tool is so easy to make that it could be redone often.
15 cm from one end, saw all around the log, leaving a heart of about 5 cm diameter. Remove the wood betwen that saw cut and the end by splitting it out with the axe. Finish the handle smoothing it with a knife, a chisel or any other tool you feel comfortable with.
You then obtain a club useful for a variety of tasks. I use it mainly to hit the axe when I split firwood, when the maul described above would be too heavy and unwieldy, but also to hit the various parts when assembling furniture.
This axe is a small one of about 800 grams I bought at the local hardware shop. The original handle broke fairly rapidly, and I replaced it with one I carved from beech. However, as I had to do it in an emergency, I used green wood, and it is starting to show some weaknesses, but the next one is carved already, drying for as long as possible (until the other one breaks) before being fitted.