Well, often I was in mountains, backpacking photo gear, and dry one day food. And, waiting to take a shot, I wanted to have a hot cup of tea.
So, I collect from web information's of all camp offered cooking completes and stoves. And, I was not satisfied.
Therefore,I involved myself in construction of portable equipment, which shall satisfy - ME.
- Good heat transfer and saving
- Smallest amount of fuel
- Protected, independent, reliable.
Step 1: I prefer Inox as material
In the cheap housewares shop I found a suitable different Inox pots, very convenient for my purpose. I do no like Al dishes and pots.
And I start to rebuild and adjust.
Step 2: Remodeling
I need to make a connection between two pots. I took a strip of Inox steel and form a necklace for inside surrounding upper part of pot/can.
To connect part I use pop up rivets,- (it can be done also with adequate screws or hart welding). It is necessary to take enough rivets to get good strong - tight connection.
Step 4: Rivets, holes, connections....
So this part was relatively easy, although a drilling holes in Inox steel is tricky... you need a special drills and start from smaller hole upwards.
Step 5: Two pots
There they are...and now to next step.
Step 6: Still steps to go...
I measure diameter, find out good distribution points for 8 mm holes and drill, starting from 3mm to 8 mm.
Than I took a small thin grinding diamond wheel and cut out bottom hole, remove the sharp edges, correct exact inside circle and...
Than I took smaller pot and insert them inside a bigger pot... and got Kpot!
Outside pot serve as:
- flame guide
- Thermos insulation
This was a goal to save as much as possible fuel consumption, to get reasonable heat transfer, regardless of a speed of cooking.
In the field I have time...few minutes more ...who cares.
Step 8: Stove
It was written, almost everything, about the alcohol stoves. The most interesting article I found in http://zenstoves.net/Stoves.htm
You tube present a movies about jet, chimney, filter ... you name it, stove.
Okay, so I took beer cans and cola cans and make a dozen models, try them ...... an finished on two which I use.
At this step I only point out on few tricky part at DIY stove:
- Cutting Al can ... it helps add few drops of oil on the blade
- Assembling upper and lover part is tricky. It helps a small bend around lower part or two mm cuts on edge al around
- Upper part need to be widen and I use two parts of cans, put inside each other to get stronger walls on which I rube the edge of
cam to wide it a little...just enough to easy glide on lower part at assembling...
Step 9: First test
In the lower part of Kpot, which was dedicated for holding stove I made gliding support to be able to adjust the height of stove against
bottom of upper pot, so the flame can be used as much as possible, for best combustion.
Ad holes around to get intake of air and oxygen, eventually to make a shimmer for regulating heat. But it works already OK.
Step 10: Kpot with chimney
Another idea which burgle my mind, was hot to use chimney effect (in old days in bathroom used wooden stove to heat water for bath).
So I purchase on scrapyard aluminum part a small conical tube an built it in the same pot as allready used for water.
It was idea that Al. shall conduct and transfer heat energy to water efficiency. And it seam that is correct.
Pros: - Faster 5-8% boiling time
- Outside walls of lower pot are colder
Cons: - Pot has smaller water volume
- Tricky to clean
- Upper cover shall have a hole to allow chimney effect
Perhaps I shall develop this in future with welded Inox conical tube - chimney from thinner material ... it could be good improvement...
Step 11: Boiling test...
And now the conclusion...
I tested inside house (cca 21C) both solutions and here are results:
In a stove I put 17 ccm alcohol.
Usual pot with 0.5L water starting temperature cca 16C to boiling in cca 14 minutes... stove burn further cca 3 minutes.
Pot with chimney with 0.5L water starting temperature cca 16C to boiling in cca 13 minutes... stove burn further cca 4 minutes.
Then I collect all parts and sew the Kbag ... it is now ready to pick up and go.