Step by Step Construction Guide
For making a Smokeless Chulha out of clay donuts
Recipe for the Clay
Find local clay and break into powder, especially any big lumps (4 parts)
Add approx 1-2 parts dry cut grass (about 3 inches long) to make the clay hold together easily
Add 1-2 parts puffed rice (or other puffed grain)
Mix in water until feels like chapati dough
Make a mold to hold the shape of the clay
Watch the Video for full explanation: (opens in new Tab) https://himalayanrocketstove.com/video-scr/
Make a 5 donuts out of clay (using the recipe provided):
hole 5 inches across (125mm)
wall 3 inches thick (75mm)
donut 5 inches high (125mm) – Add extra 1 inch height when wet to allow for shrinkage when drying
Sketch 3 parallel lines into the clay:
1 on each side of the hole
1 in the centre of the hole
Using an old saw or any kind of sharp edge (scrap metal) cut the clay while it is still a bit soft but not too wet.
A: First cut a slot from one side to the centre of the hole as shown left
B: Cut the diagonal from inside centre hole to the outside edge as shown right
You should have one donut that now looks like this, where the slot to the inside of the donut is about half the width of the donut hole itself
Get one of the whole donuts and place it on top of the slotted donut
Stack 3 or 4 donuts high to get your riser height and to make sure all your donuts fit nicely. In real life these will be rough on the outside so its more important to make sure the hole lines up on the inside. The outside can be smoothed off later.
Here we are now extending the base with either bricks or more clay.
We have taken the donuts off just to show how it looks but you can leave them on.
Now fill in the gaps on either side of the slotted donut so that the 2 rows of clay are joined to the base donut with no gaps.
On the right you can see how it should look with all the donuts stacked up.