This was a skill I did only once in a survival training course I did about 20 years ago, and for some reason never carried on with it. Lately I have started looking at survival training as more of a hobby or enthusiast perspective and less of a needed skill in the back country. This has led me more into bushcraft and less survival, although the two are close cousins.
Making a heat tolerant container that is waterproof can be a challenging. But I’m finding it to be a great way to relax and do something new in the back country.
Bowl-burning is a process of shaping wood by slowly burning it with coals from your fire. The process is really burn, scrape, repeat. After controlling the burn using coals you then scrape away the charcoal. I’m working on a couple of bowls to boil water in right now, but different types of wooden tools can be made with this method, including spoons and even canoes.
I’m using pine red-hot pine coals but really coals from hard woods will burn longer and hotter than soft wood coals. If doing this at Ft Backyard, you can also use charcoal briquettes for the grill.
To start select a piece of wood that will be your bowl. In school I used a pine round that had been slit down the middle by someone with an axe or hatchet. On my current project I am using a 5″ diameter wood round. Once your coals are ready, carefully begin taking coals from the fire with tongs. Elitist use wood, I admit to stealing a set of metal tongs from the kitchen. Place the hot coals on a chunk of wood.
Blow on the coals lightly. You can use a straw or reed to focus the air, I am using surgical tubing from my slingshot. It takes a few minutes for the wood to begin to burn. I try to not let the coals flame up, this is extra heat and can cause the wood to crack. Be careful to not let hot coals get in your eyes or drift onto you. I burned a hole in a good pair of pants this weekend doing this.
I cycle my coals through when I am making the initial burns. I let any burning charcoal / glowing wood burn for a bit and even use the embers to help shape my bowl. Once the ember does go out in the walls of the bowl, I then use my knife, a shell or stone to scrape away the char to reveal the browned wood underneath. For better control and to keep random spots from burning, wet the area or smear damp mud or sand over the area that you are trying to protect.
It takes several hours, but Keep repeating this burn-and-scrape process until you have burned out the bowl to your satisfaction.
Its an interesting skill and there is the satisfaction of making your own gear. You can actually boil eater using hot rocks, but more on that later.