Can a plain cylindrical windscreen be the pot support?

You've created a vortexing windscreen with your louvered vents. Very interesting. You'd think it would really concentrate the heat to the center and make for a very efficient system.

Now I'm wondering why we all make flat holes in our windscreens…

Smoke,

My cook pot in that picture is the generic 1 cup cook pot available from Dan (Zelph).

http://www.woodgaz-stove.com/foster-2-cup-flat-bottom.php

It has my MYOG version of a bail added to it.

Party On,

Newton ;-)

Newton, how do you deal with all those little crystals on the esbit. Your close up photos really show them well. I first discovered them this year when doing some testing. They fall of really easy and get all over the place when trying to remove it to a ziploc.

Have any of you done a side by side testing of a straight wall windscreen and a Calder Cone to see if there is any difference in heating times? If not, I challenge you stove gurus to do some testing.

"little crystals on the esbit"

I find that there are variations of the amount of crystals. It varies by the manufacture of it, so I suspect that there are tiny differences in the chemical composition. There are variations depending on the ambient air temperature while burning and the pot height (since that causes differences in the temperature when it cools). The good news is that if you successfully transfer a half-burned Esbit cube to a storage bag, it will be easier to re-light later. The little crystals light fast.

–B.G.–

Hi Dan,

If I have leftover fuel tablet I store it and the tray type stove in a small plastic container with a snap tight lid. This contains the crystals. I do not transfer the fuel tablet from the stove to a ziploc. I leave the leftover fuel tablet in the tray of the stove.

…"I challenge you stove gurus to do some testing."

I am far from being a stove "guru". A better description of me would be someone who spends mor time tinkering around his shop trying to make something that he could buy for less money and time than he spends on all of his tinkering. L O L ;-)

Empty Foster's cans, aluminum Budweiser bottles and potted meat cans abound in my shop and are my "toys" on rainy days. Everclear, Heet, 91% Isopropyl alcohol and an occasional Bleuet solid fuel tablet have fueled my experiments. I have a roll of aluminum flashing sitting on the top tray of my open tool chest. I have a hole punch dedicated to that roll of flashing.

It's time that I admit it. I'm Newton and I am a "stovie". ;-)

Party On,

Newton ;-)

Edited to include pictures

> A better description of me would be someone who spends mor time tinkering around his shop trying to make something that he could buy for less money and time than he spends on all of his tinkering.

I belong to this club!

In my defense, I have saved hundreds of dollars on gear, by buying thousands of dollars of tools to make my own.

Delmar,

"In my defense, I have saved hundreds of dollars on gear, by buying thousands of dollars of tools to make my own."

But most if not all of those tools are multi-use I'm sure. ;-)

In an effort to steer this thread back towards the original subject I submit the following link to one of Dan's (zelph) videos.

http://www.youtube.com/watch?v=a7mb-DU2sWY

I am nearing the point where I will retire my hole punch in favor of alternating "legs and slots" at the base and at the top of my windscreen(s).

Dan's idea of louvers to create a circular vortex also intrigues me.

Party On,

Newton ;-)

Edited to re-size drawing.

Delmar O'Donnell, it takes, as Jon F notes, a lot of testing, but the basics are pretty old news.

I use now 1/4" gap with a slow burning ion stove, probably in the same efficiency range as the flat cats, give or take a bit, well, probably a bit more efficient, but similar.

With a fast burning stove, you have to do more playing around with it, but one thing I'm fairly certain of is no amount of 1/4" holes at the bottom will be enough, since they weren't when testing a slow burning efficient stove, but if you cut out long slots or just make the screen stand on nubs with gaps between to form long continuous air entry points, you get very good burns and the best efficiency I have found so far. Since cat type stoves don't work particularly well on narrow pots, I don't test them very much, since I use a narrow pot. I might do some wide pot testing though just to see in the future, if I'm really bored or trying to avoid some even more boring work, or something, but my guess is, for the cat stoves: nubbed base for max and lowest entry point air inflow, 3/8" gap between pot/screen, 4" high screen, depending on how much room between pot and ground, 4" assumes 2" or so high stand/stove, shorten screen height if the gap is less. Though I'd start testing at 1/2" just to see re efficiencies and speed of 2 cup boils, but I am guessing it will be around 3/8" because of too much testing in the past. 1/4" is definitely around what you want for slow efficient stoves.

I'd have to really test a jim wood fancy feast to make sure, of course, my guess is you may need a bit more than 1/4" air gap on top, but I'd only really say that for sure after testing the stove/pot combo to see. Takes a while, the easiest is to a make a screen too big and then just test the various gaps / bottom air inlet sizes until you find the one that works best.

Also, if the screen is too tall, that will cause other very non intuitive issues, something only a lot of testing finally confirmed to me.

This year I did some testing of esbit and I blew one out and to my surprise I could watch the crystals form. The hot, liquid esbit had tiny bubbles jumping up from the surface of the remaining cube. As it cooled I could watch the crystals form. It was a calm sunny morning and it was a small scientific wonder taking place in front of my eyes. After the esbit cooled I used a toothpick to touch the crystals. They were very fragile, crumbled at a slight touch. After seeing the amount of crystals that can come off I decided to follow John Abelas lead and use the 4 gram tablets (3 per 2 cup boil) and let them burn themselves out with no residue. I don’t trust myself to control all those loose crystals. You can put the remaining esbits in a plastic ziplock or flex lid container for storage but not me, the possibility of getting those crystals into my food is too great for comfort. I now use the 4 gram tablets when I feel the urge to do the fishy esbit:-)

DY
Adventures In Stove Making