Fast results from simplicity and warming up the winter with a fan

Sun Dec 22 (2002)

I had just a bit of luck to find the proper method without the time consuming trying out of the many potential solutions, that I normally have to tackle. I described the result in my last 'News'. Then again I was lucky with the setup that came up when working with Ives. This setup is shown in the picture. Ives told me he had seen it in a recent dream. This is great, a bit of magic, a bit of proper magic when Africa is apporoaching.

What is really practical with this aid is the footrest. This is sadly just not shown on the picture, but it is a simple short stick nailed to the two battens. This footrest gives stability and control over the position of the cutting block at the top. With this device it is again possible to cut easy and safe, and without help of a second person. And it works fast!

Some news this week also on the brick stove. Hans Baarslag build a fan in a box. He and I connected this box to the chimney pipe and fitted it into a window sill. We were too cold and impaitent to properly seal the stove with mud mortar. Thus we lightened a fire in the stove and switched on the fan. There was no smoke pouring out of the many openings, like the first time we put fire to it. But soon there was the welcome warming of the metal covers on the outside of the stove. Half an hour later it felt good to sit on top of the stove. The temperature of the chimney pipe was only luke warm.
Hans and I decided to forget about making a chimney that would produce enough draft through the stove and further develop forced draft by a fan. This fan could run on electricity, but it also could be propelled by the heat of the stove. A simplified Stirling engine would be ideal for this job.

The pulley, soon in production?

Tue Dec 17 (2002)

Making sheet metal parts for the brickstove

Wed Dec 04 (2002)

The smart trick is to drive the scharp point of an ax along a line marked on some piece of sheet metal. Only the sharp point has to cut through. To let the blade sink deeper in the cut spoils the work.
The line can be straight, can make curves or sharp angles. It only takes a little practice to follow the line with the sharp front end of the cutting edge. Fast but light hammerstrokes on the flat side of the ax force the cutting.
The edge of the cut sheet bends inwards. This can be flattened, but folding it over some more, then flattening the double layer, makes the edge stiffer, soft and safe for handling.

When an 200 liter oil drum is used to recuperate the sheet metal, the cylindrical shaped side part has to be flattened. This works well by pounding it with a log as shown in the picture. Start in the middle and then works towards the ends.

Folding sheet metal is easy using almost the same method as with cutting. Hammering the ax along, but prevent to make a cut, only make a linear sharp dent in the sheet. Bend over the part that has to be folded. Sometimes it helps to fold over an edge, but with some practice just applying some force and hammerblows does the job.
A nice property of this method of folding is the accuracy of the place where the sheet folds. You get it exactly at the line that is dented with the ax.

Design, hands on

Thu Nov 28 (2002)

Zuhair removed top and bottom of a 200 liter oil drum and cut open and flattened the side. From this sheet metal he shaped the duct, that will be fastened between the top and bottom concrete slabs, outside of the wall. (see picture)
I regretted not to have available an ax or cutlass. Zuhair had to work with good quality tools such as an electrical hand fret saw and a table sheet cutter to cut the sheetmetal parts.
From experience I know that the seemingly more prmitive working with an ax for cutting and a dull cutlass for folding works by far faster and more accurate. Just an underground of dirt works best. I still have to describe these methods in this website.

Hans and myself worked on composing the setup for channels and fire box inside the brick walls.
- Directly over the concrete slabs a metal sheet rest on strips of bricks to facilitate heat exchange between the cold inlet air and the hot gas from the fire box.
- The firebox is wide at the top and narrow at the bottom. This is done by placing two tiles slanted against the outside walls. The space behind the slanted tiles functions as the channel to guide preheated air to the opposite side, where this air can enter between the grates of the fire box.
- As grates of the fire box function four tiles placed between the two slanted outward tiles. The proper distance between the tiles came from placing small stone wedges between the tiles. (see picture)

We expect it to function as follows: Fuel wood slides down from the container to the top of the grates, that is the top edge of the tiles. Burning parts falling off, slide down while burning to a smaller size. Small parts falling through, burn to ashes on a plate positioned under the fire box.
- Hot gas from the fire box moves horizontal through a channel, then up to a channel on top of the first. Then is can escape side ways into the meal ducts as Zuhair has been working on. From there flows out to the chimney (shown near the window).

Hans indicates with the empty container for wood fuel where it will later be positioned (see picture)
Building blocks with a special shape as used this time will later be cast from concrete or heat resistant cement. For this experiment Hans cut them to size with a fast running diamond disk, a very dusty job.

Frame for pulley wheel

Sat Nov 16 (2002)

Work on the Travel Bed in preparation for Senegal

Fri Nov 15 (2002)

Masoning a woodstove out of bricks

Wed Nov 13 (2002)