How to make an artistic 'J' Rocket from scrap - Rooster/Cockerel Rocket

Spike our Gold, Black-laced, bearded and crested Polish Frizzle, to give him his complete title, faces up to his metal, fire-breathing friend. Whereas, (below) the rest of the flock see this new member as an additional source of heat to the sun. Not sure about Rooster Rocket as a source of vitamin D₃ though - tea and coffee, yes. 

Improving our Coffee Making

8 years ago I made a rocket stove for using whilst working in the garden and also to avoid having to light our wood cooker just to make a coffee. The burn tube and chimney were fabricated from some scrap mild steel pipe 4" in (102mm) diameter and this was installed in an empty steel cooking oil drum donated by a caterer at an Autumn fair. I insulated the pipe by packing wood ash around it and made a burn shelf from some scrap mild steel sheet on which the fuel would sit.

The results were encouraging in that water could be brought to the boil in around 10 minutes. The fire had to be continuously monitored as the fuel needed to be fed into the burn area. The combustion was smoke free when properly tended and the consumption  of twigs was low.

L to J

Spurred on by the results from the stove, this year I decided to improve the design by changing the pipe configuration to a 'J' - tube rocket. The advantage of this format was that the fuel, being held in the vertical (the short leg of the 'J'), would gravity feed into the combustion region of the burn tube, that region would preheat the incoming fuel prior to ignition thus making a fast, clean burn without the need of manual feeding. I should stress that the amount of human management of the combustion in the original horizontal feed only arose because of the small diameter of the fuel I was burning. Larger rocket stoves burning bigger branches require much less frequent attention.

The new stove comprised 3 lengths of pipe; feed tube, burn chamber and flue/chimney. Reading around I found that an ideal ratio for the lengths would be 1:2:4 the latter being the flue length which could be longer to generate more draft. The pipe internal diameter would be the principal unit in the ratio meaning that the three pipe lengths for feed, combustion and flue tubes would be: 4", 8" and 16" (102mm, 204mm, 408mm) respectively.

Obviously, I decided to re-use the original welded pipe to give me the first two  zones of the new stove so the only additional pipe was that for the flue. The pipes were cut to a 45° angle at the joining faces to produce the right-angle mitred joint. The proximity of the two vertical sections of the arrangement did give me some concern as I thought it could give a problem with the accessibility for welding, ultimately this proved not to be the case but I feel it is worthy of mention. I also decided to cut the open end of the feed tube to 45°.  Once welded, I was able to check weld integrity by supporting the J vertically and filling the pipes to above the welds with water.

Legs for the stove were cut from mild steel bar removed from some old windows. I decided to use three legs as this configuration is the most stable when on an uneven surface. Two legs were welded at the flue side of the stove at an angle of 45° and I used the mitred weld as the guide for correctly positioning the first leg. The third leg was welded vertically down the feed tube.

I wanted all three legs to be cranked out from the stove body so as to have a more stable geometry. I laid the assembly on its side and slid a steel tube along the first of the flue-legs. By keeping my foot firmly on the leg that was touching the ground, I could bend the leg out from the stove body.

For the second leg on that end of the stove I turned the stove over, supporting the stove flue on a piece of steel I use as an anvil. Again using the  steel pipe, I could bend it out to the same angle.

The third leg had been cut oversize and once bent, I stood the stove up on its three legs to determine the correct length and cut off the surplus.

Finally I needed to attach a pot support above the open end of the flue. The distance of the base of the kettle/saucepan from the open end of the flue had to be sufficient so as not to impede the flow of the out-flowing gases of combustion. I calculated the height by determining the area of the stove flue and converting this to the wall surface area of a cylinder of the same diameter i.e. Area=πr²=2πrh cancelling h=r/2 which equated to 1" (25mm).

Using the same bar as for the legs, I bent 3 short lengths to a right-angle and welded them, equally spaced at the flue top and to a height of 1" above the flue.

Prior to the first run I dressed all the welds with an angle grinder.

Testing, Testing.....

Now for the acid test. A small amount of paper was lit and dropped down the fuel feed tube, rapidly followed by the addition of small pieces of wood. Initially,  

the flame exited out of the open end of the feed tube, a quick fanning action with a piece of card above the feed tube produced sufficient draft to drive the flames DOWN and into the burn tube. This immediately started the 'rocket' action, the hot gases passing up the flue furnished the strong draft into the burn tube to produce the hot flame and roaring sound of a functioning rocket stove. Satisfied with the successful first burn the real test began.....time for coffee.

 

At the time of enjoying our first coffee, Sue noticed that the stove, with the fresh fuel sticking out of the feed tube, had a marked resemblance to a rooster or cockerel and by welding two shaped pieces of the window bar to the flue for the beak and the addition of two spots of weld on the sides of the flue to represent the eyes, the 'Rooster Rocket' came into being.

The stove has now been used regularly over the last month and from cold, boiling water enough for two mugs of coffee is obtained in about 8 minutes. The great thing is we are burning thin twigs and rose prunings which we would find difficult to feed into our cooker or our Godin stove. The fuel feeds in without assistance and definitely produces a clean combustion providing it is bone dry. The great thing with this size stove is that it is portable enough to store in a corner of the greenhouse and can be brought out for use in seconds.......and now here's the film

If you have enjoyed this article and found it interesting then share it with your friends on social media or suchlike. Please also feel free to ask questions and or make comments and if you found this helpful and would like to support this site you can always

Until next time and from a sunny day in Normandie,

Cheers, Andy

© Andy Colley 2020

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Moving off the Grid Part One - Choosing and Using Woodburning Cookers

This will be an on-going series to explore how and why people choose their source of energy.

Why we chose wood

Simple primitive living, when we started our new life in France
Christmas 1999 with our plum pudding cooking on the Godin.

Winter is rapidly approaching and inevitably folks are thinking about heating their homes. When we first arrived here the Spartan heating was a massive granite fireplace, the chimney of which, 1.70m by 0.70m, was blanked off  and a crudely made open-fronted firebox. This had a swan's nest grate sitting in the centre of the hearth, with its flue passing through a hole in the blanking-off plate. There was plenty of wood-fuel left by the previous owner in the outbuildings, so for the first few visits here, this crude open fire became our sole  source of heating and cooking. After all, you can’t carry kitchen appliances on a motorbike. 

When we began to live here permanently and renovate our house, we bought  an insert, a made-for-store Godin from a DIY Superstore and fitted it into the fireplace using blocks, which we then covered with decorative tiling. This looked like a Swedish ceramic stove but the output fuel-to-heat was poor and we were still reluctantly using an electric hot plate and mini cooker. After having returned the malfunctioning hotplate to the store for the 9th time, we decided enough was enough. We therefore, began to research woodburning cookers as a possible heat and cooking source. By now we had fully insulated the bare stone of our kitchen with hemp and lime and were not really wanting to break through this to install water pipes, so we went for a cooker without the advantage of a wraparound boiler. We also wanted something with glass windows so we could check on the cooking and ;have the cheering effect of the flames. Firewood is plentiful here, although year by year the price rises significantly. However, we are neither of us happy with burning magnificent oaks and beeches and we realised we could easily collect a supply of pallet wood to keep us going throughout the year. To this end our heating bill for the past three years has been zero.

Using the top of the cooker to heat water, combining this with a solar shower bag in summer and the creation of our own bicycle-powered washing machine, means we are now consuming 85 kWh of electricity every month at a cost of around 7 Euros. We have therefore, reached the point where we should quit the Grid but our house is on the market and unfortunately this has to be a consideration.

So what does our wood burning cooker do for us?

Heats all our hot water,
Cooks all our food
Dries fruit, flowers, vegetables and herbs
Dries clothes

Heats an iron

What electrical appliances did we get rid of?

Hot plate
Mini oven
Toaster
Kettle
Bathroom heater
200 litre immersion heater
hair dryer
iron

Our woodburner is not recommended by the manufacturer as a pallet-burner but some makers do promote this viz., Esse. The only problem we have found is that the flueways within the cooker need clearing of soot twice a year instead of annually when the chimney liner is swept. We also now have the little Godin stove (seen in the above photo) in our sitting room and this also heats the bedroom above it.

How to chose a Wood-burner

Our woodburning cooker with the now rarely-used insert.

We chose a Lincar, which was made by a company which had started up in business as a manufacturer of wood-burning cookers and then gone into the manufacture of wood-stoves. Most firms we looked at had started with stoves and then gone into wood-cookers, we also found that often they did not manufacture the cookers they sold. It is very important to check the labels on the back of wood-cookers so as to ascertain who makes them and where. This way you can check the full specs, designs and prices at source. The firm, we chose had an extra commendation for us, in that it also made cookers for the Catering Industry. We bought it over the internet, which was worrying, as we had no prior experience in this. It was also impossible to find a showroom nearer than the Italian border where we could actually see the cooker. Another problem was, that in 2008, when we bought the cooker there were very limited reviews of wood-cookers on the internet. However, the company we bought ours through was a small family concern and the person we dealt with had excellent technical knowledge and we had managed to build up quite a rapport with her before we finally bought it. She was also able to provide good quality stove piping direct from the factory and free delivery of the cooker from Italy to France. Hey, we even got a free oven mitt!

Combined with buying our wood-stove the most important thing we did was to fully insulate the house. How we did this with ecological materials is the next chapter of this blog. I will also be writing a piece on how we sourced and made our bicycle washing machine.

What happens in Summer?

 In the hotter months we still use the wood-cooker but only at meal times. Having espoused a French way of life we have a main cooked meal at lunch-time and a cooked meal in the evening, we also have a cooked breakfast. To provide hot water throughout the day I constructed a pallet wood hay box which keeps the water hot for the hours between lighting the cooker. To heat up a kettle we also use a home-made rocket stove. I found the information how to make one of these on Youtube but I have since found that the wood-gas burner, which you can make from similar recycled materials is more efficient but I have yet to make one and verify this.



This image shows our hay box in construction, I completed it with a pallet wood finish to hold in the hay and an insulated lid. Within the box water will keep hot for 4 hours and stay warm for up to 8 hours. This box can also be found as a Victorian cooking technique in Mrs Beeton's Book of Household Management published in 1875. 

Below are two of our more recent designs for a hay box. The first, a simple cheap and cheerful cardboard one (pictured below) and the second a more sophisticated pallet wood one. There is also a film of our trip to the beach in Winter, where we test both designs!

Factors to consider before you decide what energy requirements you need;

1. Be brutal. Start by cutting consumption, this is easier than creating energy.

2. What are your strengths. i.e., what energy sources are plentiful?

3. What are your needs – heating, cooking, hot water, drying, lighting ……

4. Budget and capital expenditure, including maintenance costs.

5. Personal strengths/skills

Wood is cheaper in large volumes but these will need sawing, carrying and storing. Solar, wind, geothermal and wood are cheaper if you can install your own systems.

6. Continuing education

Ask around, look what other people are installing, also visit Fairs and Salons/Exhibitions on Organic and Alternative Living. There are now more opportunities than ever for residential and day courses on alternative energy

A taste of something better - Guichen (Brittany) Salon Bio 2011 - Organic and Green Living Fair. These types of fairs are held yearly all over Europe.

All the best and thanks for dropping by. If you enjoyed this article feel free to share it, comment and/or ask questions.

Cheers, Andy

© Andy Colley 2014

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