This is just one variation of a "rocket stove" - a simple appropriate technology for cleanly burning bio-fuels.
The rocket grill is fired by twigs, wood scraps, wood chips, or nearly anything else you can put in it. It naturally drafts air to maximize combustion. Once the the grill is really going, NO smoke comes out the top, only heat, and the grill really does sound like a rocket!
The grill is designed to not only grill, but also boil, bake, braise, and roast!
Because of the simple design and robust construction, it is nearly maintenance free. Unlike an LP grill, the burner will never burn and rust away to nothingness. (And cost good time and money to replace.) There is no piezo-electric starter or other "modern" technology in the grill, which would be prone to failure.
Despite how it looks, the grill is small and light enough for one grown man to lift into the back of a pickup truck. That way, it can travel with for camping or tailgating. (The lid and side tables are also removable for storage and easy packing.) Because it's covered and enclosed, it also qualifies for use as a "backyard fire-pit" in areas that do not allow open fires.
This project is mostly simple metal work. While it does require welding, it's pretty straight-forward. This was really my first-ever welding project.
So lets' gather together our tools and materials and get started!
Step 1: Tools and Materials
- Angle Grinder
- Grinding disc
- Cut-off disc
- Safety glasses, work gloves, welding gloves, Welding helmet, hearing protection
- Drill and drill bits
- OPTIONAL: Laser Level, Bubble Level
This project is made mostly from scrap metal, but will need several other parts.
Parts for the Grill itself:
- A Base. Something for the grill to stand on. Must be heat-proof. I used a scrap steel farm implement disc.
- Steel Pipe - Diameter of your choice, but will effect cooking size and fuel rate. I used 6.5 inch diameter scrap steel pipe. About 3 feet in length.
- Steel Water Tank. This becomes the "bowl" top of the grill and cooking surface area.
- 4 x pieces of small diameter steel pipe, about 6" in length
- 2 x 90 degree pipe elbows of same diameter
- 2 x pipe flanges of same diameter
- 2 x pieces of flat material that you like to make side countertop surfaces
- Small scraps of steel plate
Parts for the lid of the grill:
- A piece of wood, species of your choice, sized for a lid handle.
- 2 x Carriage bolts (about 5" long) with matching nuts and washers. Stainless steel is ideal, as these will be exposed to both heat and the elements. Plain steel is fine, lower cost alternative.
- 2 x pieces of copper or steel tube or pipe, slightly larger diameter and shorter length than the carriage bolts, to use as spacers.
- The top end of the water tank.
- Steel plate, about 6" side by 12" long. Perferations or slotted is ideal.
- JB Weld
- Large Diameter Pipe
- Water Tank
The large diameter pipe needs to be cut into two sections. Make one about 1 foot, and the other about 20" long. The 20" section will be the "vertical tube", and the 1 ft. section will be the "feeder tube"
That water tank that I chose was 16" in diameter. It was already cut apart from a solar water experiment I worked on. The bottom section of the tank is cut to about 1 foot tall. This becomes the cooking area "bowl" top to the grill. The water tank was also chosen because is is large enough diameter to fit my camping cast iron Dutch Oven, and a stock pot that I use for boiling corn.
Stacked up, the base, vertical tube, and water tank section should come to a comfortable standing height for you. The top of the water tank section is the height that grilling will take place.
To cut the steel, I found that an angle-grinder with a cut-off disc works best. I cuts quickly, without removing to much metal, and makes a nice, straight line. You could also use a reciprocating saw with metal cutting blade, or a plasma-cutter if you have access to one.
To mark a line on a cylindrical object like the pipe or water tank, wrap a straight section of sheet metal around it, and secure with masking or duct tape. Mark this line with a permanent marking pen, then remove the sheet metal.
Cut the pipes and water tank to length, using common-sense safety precautions. (Wear work gloves, eye and hearing protection, etc.)
Cut the top off the water tank, and save to make the lid.
Stack up the base, vertical pipe, and water tank section to get a feel for how your grill will look. If you ware working on a level surface, like a concrete garage floor, you can use a bubble level to make sure your vertical pipe is perfectly straight up and down. (Plumb!)