Make a Wooden Fuelless Cooker or Hay-box - No Power? No Worries. Hot Food.

The cardboard box version of the fuelless cooker as described in my post a few days ago is fine as a 'quick fix' or an emergency back-up. In this post I'll share how to make a more robust model which you can keep to hand in the kitchen or, as we show in the film, to take in a car to provide hot, nourishing food on a journey. There are two ways you can use a fuelless cooker, firstly you can use it to cook a whole meal, this was the way it was used in previous centuries both for men and women working in the fields and long distance travellers and how we used it in the film. Secondly you can use it in your kitchen, to save energy when cooking a stew or similar dish, which requires slow cooking. We actually did this too with our cassoulet when we returned home in the evening, taking it from the box, where it was still quite warm and transferring it to our wood cooker. I have to tell you that after several years of making and eating this dish it was the best we had ever eaten! Furthermore we had saved on four hours of fuel.

Design and Materials

Our wooden box sits next to the telephone and is robust enough to act as a comfortable low seat. It was made using pallet wood and 10mm (3/8") thick pine cladding. This latter was left over from when I made the hen house last year. The insulation was 45mm (1¾") thick organic hemp and vegetable fibre, purchased in a 1250mm x 600mm (4' x 2') sheet for about $5.00.

I based the design of the box around our largest saucepan and for ease of loading when hot, the lower portion of the box was not much higher than the two handles on the side of the pan (as seen above). The box lid was deep enough to fit over the portion of the pan standing above the box rim.

Both the base and the lid were made in the same way, that is the vertical sections that made up the inner and outer walls were stapled to an upper and lower square frame, the width of the frame was the thickness of the insulation. 

I arrived at the box dimensions from the size of the saucepan. This size would be the minimum internal dimension of the box. To arrive at the outside wall height for the box base I had to add the thickness of the box bottom, the insulation and the thickness of the platform wood. I always tend to regularly check the measurements especially prior to cutting the wall material - better to be safe than sorry!

I had originally thought of making the frames like picture frames, with mitred corners but decided against it for two reasons, one is I'm pretty crap at achieving consistently accurate cuts, especially at 45° and secondly and more importantly I didn't believe that sort of joint would be strong enough to cope with the load from a pan full of hot stew! 

Construction

 


Select the pallet wood for the frames, cut to width (that of the insulation thickness) plane it smooth and cut to length.

Four frames are needed (2 for the base and 2 for the lid). To ensure they are all exactly the same size assembled them in a jig. I made this by screwing three straight pieces of wood in a 'U' shape to a piece of chipboard. The size of the U being the size of the frame and the corners at right angles. 
    

Position the two vertical legs of the 'U' against the sides of the jig and check that they touch the bottom jig edge, apply wood glue (PVA) at the corners and put the third, horizontal part of the 'U' along the corresponding jig edge. Ensure that all 3 pieces are pushed firmly against their guides and staple or nail where they overlap. Turn the, now joined three wood pieces around in the jig so that the fourth, open side of the 'U' is sitting against the bottom jig edge. Once again glue the corners and position the fourth piece of the frame on top and staple or nail.
 
The reason I used a 'U' shaped jig and not a complete square is that it is much easier to remove the frame by sliding it out rather than trying to lift it.
Repeat for the other three frames and then stack all four frames and clamp at each corner and leave to dry.

The bottom face of the box has pallet wood planks nailed to the frame to form a solid support.

Turn the base over and cut and fit two extra pieces of wood to the frame. This is to furnish a vertical face to which the box walls can be attached.

The saucepan is to sit on an insulated platform made to fit into the square recess created in the previous stage. The platform is about 20mm smaller than this recess to account for the wall thickness and is deep enough to fit a square of the 45mm thick insulation beneath it. Being removable it can be taken out and cleaned if there is any spillage.

 

Now comes the clever bit, I already know the height I need for the box base so I measure the internal wall height and include the height of the insulated base. Cut the 10mm cladding to this length.

Use panel pins to attach the walls to the base. Ensure a good fit at the corners.

The base now looks like this. 

Prior to fitting the top frame to the base, attach two additional wooden pieces, so as to make a flat surface to the frames upper face.

Nail, or staple the top frame to the walls of the base.

The box now looks like this. The outside walls can be cut to length and the insulation cut to size for the walls and the insulated platform.

 

The insulation should be a good, close fit to ensure maximum efficiency.

Attach the outer cladding. I tend to use the stapler because it's less tedious but panel pins are fine.

Cut two carrying handles and fix to the box, screwed through the walls into the upper frame.

The insulated platform can then be dropped into the completed base.

The construction of the lid is similar to that of the base except that the top outer cover of the lid is put on last. I found that this makes it easier to attach the inside walls to the frames.

 

First, cut the interior walls to length, which is the height of the pan  and lid projecting above the box base plus the insulation thickness and the thickness of the cladding covering the insulation.

Fix the interior walls to the lower frame........

............and the upper.

To make the space for the insulation at the top of the lid cut two 45mm wide pieces of wood to the internal dimension of the lid and wedge them in place at the top of the lid, with a few millimetres protruding above the uppermost face.

Cut cladding to fit to these two pieces and attach. The cladding must not overlap the edges.

Remove this assembly, turn it over and put it back into the lid top.

 

Tap it flush to the upper face of the frame..........

..........and attach to frame.

Cut insulation for walls and

top, cut cladding and attach.

Cut and attach two handles, securing them, as before, by screwing them to the upper frame.

 

To ensure a snug fit of lid to base, cut four pieces of fruit crate wood (5mm pine), to fit around the inside of the lid perimeter and chamfer one edge of each piece.

Staple, or nail these pieces to the inside wall of the lid, chamfer facing out and protruding about 10mm. This acts as a guide to align the lid to the base and produces a more effective seal to prevent heat escaping.

And there it is all ready for the next power outage, energy price hike or picnic.

Bon appétit! Now if you'd like to sit back and watch the film: 

If you would like a cheap and cheerful project, which is great fun to make and use, then take a look at my cardboard box fuelless cooker design


Thanks for dropping by and please feel free to share this article, comment, ask questions and if you'd like to be assured of getting the next post, then sign up to follow this blog.

All the best, Andy

© Andy Colley 2014

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How to Make a Simple Fuelless Cooker or Hay-box - No Power? No Worries. Hot Food.

Here's a quick and easy way to use less fuel, less water and still have a tasty and nutritious meal from a cardboard box. Get one ready in case of power outages or for hot food on a journey or emergency.

The Hay-box or fuelless cooker was a popular item around the turn of the 19th to 20th century. In particular during the World Wars and the Great Depression when people were often displaced and the price of fuel rose steeply and/or was rationed. Furthermore, it provided a form of cookery which used less water and in which, precious food, cooked at an even temperature by residual heat had no chance of burning and becoming spoiled. There was also the added and important factor that nutrients were retained through the slower and lower cooking times and temperature.
 

 

We cook all our meals and heat water with our wood-burning cooker. In the colder weather it is alight most of the day heating the house as well. As we move into the milder weather we tend to eat more raw food and as we have no need of the heating so the cooker is alight just around meal times. This poses a problem in that we do need hot water for washing hands when we come in from the garden prior to preparing our food .

 

We solved this problem by using a Hay Box to keep the water, heated at meal-times, hot. We made our first box from scrap wood and filled it with organic lucerne hay which we are given by the organic dairy farmer from whom we buy our chicken grain.

The idea is not a new one, in our 1920’s copy of Mrs Beeton's Book of Household Management the Fuelless cooker was used to cook meals for a fraction of the fuel cost. Nowadays it is just as important to consider the fuel-saving benefits of such a system as well as bearing in mind the possibility of providing hot food during power outages in the colder weather.
 

The principle is that the heated food is placed, in its pot or saucepan, into a well-insulated box , the lid which is also insulated is put in place and that’s it! The food takes about 4 times longer to cook completely within the box and may need to be reheated prior to serving but the only  energy consumed has been that needed to get it to boiling point. Of course, the ‘box’ part of the system is only required for safety and neatness and possibly transporting, I know of others that have simply wrapped duvets around the heated pan and achieved the same end result and have a warm duvet to boot!

 
 
ORGANIC LUCERNE HAY

ORGANIC TRITICALE STRAW

ORGANIC VEGETABLE FIBRES

ORGANIC HEMP AND LINEN

HOLZFLEX WOOD FIBRE

ORGANIC SHEEP'S WOOL


I used an ecological, non-toxic insulation for my box and there are a multitude of suitable insulation you can use: fleece material, multiple layers of corrugated cardboard, hay, straw even expanded polystyrene, the choice is yours. 

The first box I’ll share is the simplest and cheapest. We are very fortunate in having a local ecological building supplies company (in fact it’s next door to our organic supermarket) and I could buy single panels of  wood wool insulation 30mm thick for around $3,00. On  the same visit to buy the insulation we popped into the organic shop and picked up two cardboard boxes of similar proportions but different sizes. 

The insulation needs to be cut to line the four sides and base of the larger box and the smaller box should fit in the cavity that remains. I was able to find cartons whose sizes differed by about 60mm hence the 30mm insulation on the inside walls of the larger carton would be sufficient to form the space for the smaller carton.

 

To make the lid to the Hay Box I cut two rectangles of cardboard to the size of the larger carton and made a ‘sandwich’ with the insulation between them. The lid was held together with broad masking tape. I adhered the tape around the perimeter of the lid so as to seal in the insulation.

And that’s it, the box is ready to go. When the saucepan is put into the box, the voids at the box corners can be filled with triangular-shaped pieces of cardboard (a bit like ‘Toblerone’ boxes) or stuffed with tea towels, ideally any kind of insulating material which will reduce heat loss due to convection currents.


Next time I’ll share  my design for a wooden hay box, more robust than the cardboard one it is more suitable for carrying hot contents in a car so you can enjoy your own hot food on a journey.

Meanwhile, if you'd like to, sit back and enjoy the film:

Thanks for dropping by and please feel free to share this article, comment, ask questions and if you'd like to be assured of getting the next post, then sign up to follow this blog.

All the best, Andy

© Andy Colley 2014

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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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