Written and invented by Paul Clacher Copyright 2003.
Ever gone camping and wished you could have a compact stove
and oven that could give you continuous hot water. Well so did I. So I invented
and built one. I thought about this one for a while until I came up with what
I thought to be the perfect solution. First of all the main fire holder is an
old car wheel rim. It doesn't really matter what diameter you use, but the deeper
the rim the better. I then had a 1/8 inch steel sheath cut and rolled to the
exact same circumference and width as the rim. I then had the air hole welded
up on the rim and the sheath welded very carefully to the rim. Perfection here
is very important as any leaks will cause the hot water system to be a failure.
I then had an inlet funnel welded to the outer sheath. This I made so that it
can be screwed off when packed. I then had an overflow and steam vent welded
to the side. You can see both of these in photo 2. If you look carefully in
photo 2, you can see steam coming from the steel funnel. I then had a screw
tap braised to the bottom side of the sheath on the opposite side. I then had
two handles welded to the side of the cooker on opposite sides at the top. You
can see the handles in photo 1.
For the cooking plates I had two round plough blade cut to the same diameter as the rim, so that they fitted neatly into the rim lip. Usually I only use one. When I use the second one I place it on upside down so that I can then use it as an oven. It bakes very nice flat bread or even a pizza. Just throw a few coals on top. The centre hole allows some flame out, but at the same time it causes the cooker to burn in a slow combustion mode. Oh yes, the cooker only needs sticks to cook with and they burn for ages. Saves on chopping up loads of fire wood too. The holes in the rim allow the fire to draw air. You may also see in photo 1 that I use a grill plate for cooking with a flat surface. I would suggest you make and use what ever grills work for you.
The endless hot water. Before you use the new cooker, run anti rust paint through the cavity of the rim and allow a week for it to dry in the sun. Then run another amount of pot-belly black paint (special heat resistant) through the cavity and allow for another week for it to dry in the sun. Don't forget to paint the outside too. You can also see I added three legs which screw onto the under side of the rim. I also made these legs so that I can break them in half. Well now your cooker is ready to use. I would recommend though that you only use the hot water for washing up dishes or for shower etc. Not for drinking. ALSO A WORD OF WARNING. BE CAREFUL WHEN FILLING THE RIM. IT CAN OCCASIONALLY SPURT BACK. This only usually happens if the system has been allowed to be emptied and you are pouring water into an empty cavity. JUST USE SENSIBLE CARE. After all it is boiling water. I would recommend filling the cavity prior to lighting the fire and making sure that you keep some water in it. It comes out so hot that you will have to mix it with cold water anyway.
The water takes only about 5 minutes to boil and the rim holds about 1 gallon or 4 litres of really hot/boiling water. I have found it to be just brilliant in the bush. The best thing is that is folds down to the size of a wheel rim. If you want to make one for personal use go ahead. But, I would be a little upset if it was mass produced without my permission.
The New Improved Small Bush Cooker
Some time ago I had a story published in Gold Gem and Treasure Magazine about the above invention I made some years ago. The Cooker worked exceptionally well and boiled about 4 litres (1 Gallon) of water in one go. It also doubled up as a fireplace and bush stove. The only thing I could say not in its favour, was that it was the same size as a car wheel. It was very good for extended bush camping where you wanted lots of hot water and you wanted a fire place where you did not want to be permanently chopping up fire wood for it. The beauty of that cooker was that it ran on small sticks and small logs. In fact I still own the original Bush Cooker and when we go on extended bush trips I always take it.
As usual I got to thinking how could I improve the above cooker. I had a couple of old Holden wheel discs and it got the brain a going. And this is how I built it. I had a front Holden disc assembly (drum / fins), 2 frying pans, and a wok. I placed the disc into the frying pan, which is a very comfortable fit and I thought to myself, if I built a fire in the disc cavity and it was immersed in the frying pan where there could be some water it would boil that water, just like it does in the wheel cooker. So I fitted a copper tube into the handle position of the frying pan. I did this by placing a copper collar around a small length of copper tubing and then soldering it in position. The angle that it then sat in on the side of the frying pan went up into the frying pan around the 45% degree mark. I then riveted the tube and collar into position using another fashioned collar and some silicone glue to seal the joint onto the frying pan. This then formed the basis of the mule / donkey hot water system.
The mule or donkey hot water system works on the physics principal or principles of convection and displacement. How it works is like this. If you have a closed drum and you can get cold water into the bottom of the water filled drum and have an outlet at the top of the drum, then the amount of water you put in comes out. Hence, the displacement part of the theory. Now, if you place the drum onto flames, the physics principal of convection comes into play. The cooler water sits at the bottom of the drum and the boiling water rises to the top of the drum. So, when you pour cold water into the bottom of the drum the boiling comes out of the top of the drum through the spout. Anyway, that is the end of the technical lesson how the hot water part of the bush cooker works.
I then drilled a hole into the top of the fins on the disc and then riveted a copper tube underneath that hole so any water poured in would go to the bottom of the frying pan. I then used silicone (Silastic) to seal the disc into the frying pan, so it cannot leak. I then drilled holes at the centre of the hole of the disc and the frying pan and the Wok. The cooker actually has one large hole in the centre with a diameter of 4.5 centimetres. A bit hard to imagine I think, but you can see the holes in the wok in the below photograph. Those holes act as the bottom breather for the fire.
How the cooker works:- You fill the cavity in the frying pan with water using a stainless steel funnel, which is also pictured. As described above, it works like a donkey / mule hot water system. As the water poured in exceeds the capacity of the cavity of the area between the frying pan and the disc the hot water is displaced and pours out of the copper tube on the side of the frying pan. The fire in the centre boils the water.
I have placed the system on top of the up turned wok, which also doubles as the container for the entire system. This raises the cooker system above the ground so that you can place a container under the spout where the hot water comes out. This raising of the cooker also allows for fresh air to be drawn into the fire. On top of the disc and fire you place the 2nd frying pan. I this case I use a cast iron frying pan. Hey presto a stove / cooker and a hot water system is there for you all in one.
The entire system can be fuelled with the smallest amounts of wood chips, sticks and twigs or even heat beads. For the initial starting of the fire I would use a firestarter, just at first. For it to work well, do not over fill the disc with too many sticks. The most important aspect of a good fire is for it to be able to breath. Fires need a good flow of air in. Because the wheel disc has fine holes in the design of it, these holes actually act like a chimney and draw the flames out to the circumference of the disc itself. This then heat up the top of the disc like a hot plate and allows for a pretty good flow of air even when the frying pan is placed on top. In the above photograph I have the funnel in one of the holes of the wok just sitting out of harms way. The entire system with the frying pan on top will also cook like a slow combustion stove.
This is a pretty easy system to make. It costs nothing more than a few pots and pans to make. And how many old pots and pans do the hardened camper and fossicker have. Heaps I reckon. As you can see in the photographs this system is lot smaller and more practical than the original system I made using a car wheel. Oh yes, I also painted all parts with rust converter and potbelly black before I assembled all of the bits. I have used the above system in the bush and it works very well. I can say that you will have a permanent hot water system within 5 to 10 minutes of starting the fire. Just remember, fill the cooker with water first, before starting the fire. Good luck with making your own and happy camping and fossicking.
Written and invented by Paul Clacher Copyright 2003.
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