This project goes into the build of an efficient portable ammo can wood stove that can warm your space, act as a cooking stove, baking oven, and an alternative for ground fires at camp sites. This ammo stove is compact and doesn’t take up additional storage. All the basic components used in this stove are modular and can be stored inside the stove when not in use. These components are easily available in your local hardware store.
STEP 1 : THE MATERIALS REQUIRED
The basic components needed to build this stove are as follows. The ammo box called the “fat 50 “is purchased from an army surplus store for $30 , the titanium stove pipe for $100 , the metal for the control dial and the door is salvaged from old barbecues. The rest of the basic tools needed are a grinder, blow torch, hack saw ,and a drill press.
Not only you can use wood logs, paper, or twigs but it also runs on wood pellets. The system has a gravity-fed hopper that feeds the pellets intermittently for consistent heat over a longer period of time. For maximizing the burn, a divided combustion chamber is used. This forces the burn to go around a sealed baffle before it exits out the stove pipe providing less smoke and retaining more heat.
A thick steel plate is used as a cooktop which is rescued from an old barbeque. This plate absorbs the heat for cooking and is removable thereby protecting the stove top. An additional feature is a baking oven underneath the stove.
STEP 2 : REPLACING THE RUBBER GASKET AND REMOVING HANDLES
The first step to build is simply removing the lid of the ammo can stove which just slides off the hinges. Remove the rubber gasket on the backside of the lid using a plier.
This rubber gasket is replaced using 3/8th inch stove rope. This provides heat resistant seal from smoke.
Remove the handle by drilling along the spot welds on the sides of the handle just enough to weaken them and pull it using a screwdriver.
STEP 3: INSTALLING THE STOVE PIPE
Two holes of three inches are drilled at the top surface of the stove. These are done to fit in the titanium stove pipe and for the gravity-fed hopper system. We use a three-inch propane fuel cylinder tube to make a pipe collar as a guide to trace out the holes. These pipe collars act as hopper support for gravity-fed pellet mechanism and for securing the stove pipe. The hole for the first pipe is about five and a half inches away from the door hinge and the second, one and a half inches away. The holes are then cut using a jigsaw.
The flanges in the stovepipe collars are made by securing them against a wooden fixture and bent them using a hammer. The edges are heated with a torch to anneal the metal for hardening.
Before inserting the stove collars into the lid, the metal sheet inside the lid was removed. Using fiberglass cloth, a smoke seal is made around the collars. The collars are then inserted and the metal sheet is reinstated with help of some stainless steel rivets.
STEP 4 : DAMPER INSTALLATION
An adjustable damper is installed inside one of the collars. These dampers provide control to both burning speed and fire intensity. Also, the damper in a closed state also acts as a base for a steamer or a boiler. The damper is made using thin steel cut out of disc, the size of the inside pipe diameter. The shaft from a barbeque skewer is inserted along slots drilled in the disc holding them underneath the collar.
STEP 5 : DIVIDING THE COMBUSTION CHAMBER
Inside the combustion chamber,we have two dividers installed. One divides the combustion chamber and the bottom one separates the oven from the stove. The top divider acts as an inner wall. The combustion has to travel around the corner and then go outside through the stove pipe at the end. This collects more heat and has less smoke built up inside.
STEP 6 : INSTALLING THE SIDE DOOR
The side door openings are four inches high and three and three-eighth inches wide. The door is made out of a thick steel plate that was salvaged from an old barbeque. The door has three holes for the air intake and it is supported by a regular door hinge. A small circle metal piece at the front regulates the amount of flow that goes into the stove.
STEP 7 : SECONDARY BURN CHAMBER INSTALLATION
A secondary burn system is introduced inside the stove so that the air coming into the upper part of the combustion chamber where all the smoke ascends gets reignited. This drastically improves the efficiency of the stove. Here we use a couple of half-inch black iron pipe that is connected with 2 90 degree elbow and an end cap. Holes are drilled on the pipe so that the fresh air is introduced into the chamber. A hole at the side of the stove is made for the air intake. The pipe is inserted into the chamber and secured in place using a coupling and a spacer.
STEP 8 : GRAVITY FED HOPPER FOR SUSTAINED RELEASE
A 3 X 4 inch duct adapter is used as a funnel for the gravity-fed hopper system. To make this efficient, we add a small cage made of a door basket inside the chamber so that all the pellets won’t drop suddenly to the bottom. The cage is made from the metal rods from the basket. The rods are spaced 8mm apart and put straps across both sides and secured it using rivets. To prevent the overflow of pellets inside the cage, a two and a half inch tailpipe is placed at a specific distance below the hopper. This helps the pellet build up in the cage but not overflow. Now there is a sustained release of pellets at all times for a consistent burn.
STEP 9 : ADDING LIGHT SOURCE
Stainless steel tent stakes are placed at the bottom of the stove riveted to a metal plate. This prevents the bottom from burning out and also improves airflow. Also acts as an ash collector.
To use this stove as a light source, we make a small window out of half mm natural mica glass. We use a fiberglass cloth to form a seal around the window. It is held by green painter’s tape. After positioning the glass, spacers are added around the edge. These metal strips allow for the mica to expand and contract. Another metal frame is used to hold all these in place.
The portable stove pipe is made out of titanium rolls. The titanium prevents corrosion and also distributes the heat efficiently. To make a long cylinder without denting the foil, unroll the film across the ground, roll it small enough to get the clips on and spacing them evenly along the length of the pipe.
Image Credits : Slim Potatohead