Subscribe Contribute Advertise Facebook Twitter Instagram Forums Newsletter
Can a plain cylindrical windscreen be the pot support?
Display Avatars Sort By:
Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Scoop Shaped FTW on 11/19/2013 21:40:13 MST Print View

...and the appreciation for the design of the Caldera Cone continues to grow.

Sometimes things aren't quite as easy as they look.

Go Rand!

Edited by greg23 on 11/19/2013 21:55:17 MST.

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Can a plain cylindrical windscreen be the pot support? on 11/20/2013 04:38:23 MST Print View

Delmar,

It worked for me in testing using my tray type Esbit stove.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=68338&skip_to_post=587454#587454

Combo windscreen and cookpot support

Tray type "Esbit" stove with partially burned fuel tablet

Stove inside of windscreen / cook pot support

This was a test at home and in controlled conditions. To date I have not used this set-up in the field. I did however try to simulate windy conditions using a box fan and only saw flames licking out of the top exhaust holes.

Most of my alcohol stoves serve as their own cook pot support. I do however see the possibility of a windscreen / cook pot support working with an alcohol stove that doesn't support the cook pot.

Your stove will have to breathe so the ability of your screen / support to "draft" will be important as will the height of your cook pot above your stove.

FWIW I've found that holes do not work as well as vents / cut-outs on the bottom of a windscreen. The same may be true for the top of a windscreen used as a cook pot support.

Be careful and enjoy the experimentation. As I've learned with alcohol stoves there are no guarantees of performance or safety with a new or adapted design.

Party On,

Newton ;-)

Buck Nelson
(Colter) - MLife

Locale: Alaska
Windscreen/tent stake stand on 11/20/2013 05:15:50 MST Print View

Years ago when I hiked the A.T. I used a standard MSR windscreen with two aluminum gutter nail stakes driven through it as a pot stand and wind screen. It worked great and I believe was quite efficient as the flames went all across the bottom of the pot then were directed up the sides. There is a small photo of it about half way down this page.

D S
(smoke) - F
Pot on 11/20/2013 08:28:57 MST Print View

Newton,

What kind of can are you using for the Pot in your pic?

Dan Yeruski
(zelph) - MLife

Locale: www.bplite.com
Re: Re: Scoop Shaped FTW on 11/20/2013 09:10:39 MST Print View

Dale, a while back I started working on a louvered windscreen. I was amazed how well it works. It's work in process.

Click on the large black square, it's a photobucket video made at night in my garage. It starts out by viewing the underside of the stove (StarLyte) and pot thru a sheet of glass. I am observing the flame pattern as it swirls around under the bottom of the pot. No flames are able to pass out and beyond the bottom edge of the pot. I then go from under the sheet of tempered glass to the top of the windscreen and remove the pot to show how the flames are swirling around. Lots of stuff going on there....turbulence and centralizing of the flame.

A small 15 gram stove with pot support would be ideal for what Delmar wants to do (sorta) He has the burner for simmering. I have a batch of them waiting for me to install the ss pot supports.

The louvered windscreen, a StarLyte stove and Foster's pot make for a good kit. I will make them available after the first of the year.


 photo whirlwind001_zps2d4a0011.jpg

 video WhirlwindWindscreen_zps87f0057c.mp4

The use of crenelation pot support worked well in the Ti windscreen I designed a while back in this forum

Here is a combination square windscreen and storage container:
Square Windscreen/pot support and storage container

DY
Adventures In DIY Stove Making

Edited by zelph on 11/20/2013 09:31:44 MST.

Delmar O'Donnell
(Bolster)

Locale: Between Jacinto & Gorgonio
Vortex. on 11/20/2013 10:18:08 MST Print View

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...

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Pot on 11/20/2013 11:03:46 MST Print View

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 ;-)

Dan Yeruski
(zelph) - MLife

Locale: www.bplite.com
Esbit Crystals on 11/22/2013 14:29:20 MST Print View

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.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Esbit Crystals on 11/22/2013 15:05:19 MST Print View

"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.--

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Esbit Crystals on 11/22/2013 15:23:13 MST Print View

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.

Plastic storage case for stove & leftover fuel tablet

Stove and fuel tablet in snap top plastic case

..."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

Edited by Newton on 11/23/2013 06:11:41 MST.

Delmar O'Donnell
(Bolster)

Locale: Between Jacinto & Gorgonio
Re: Re: Esbit Crystals on 11/22/2013 21:59:04 MST Print View

> 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.

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Re: Re: Esbit Crystals on 11/23/2013 06:52:10 MST Print View

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.

Proposed louver idea drawing

Party On,

Newton ;-)


Edited to re-size drawing.

Edited by Newton on 11/23/2013 08:18:14 MST.

Harald Hope
(hhope) - M

Locale: East Bay
enough air on 11/25/2013 16:30:59 MST Print View

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.

Dan Yeruski
(zelph) - MLife

Locale: www.bplite.com
Re: Re: Re: Esbit Crystals on 11/25/2013 18:45:03 MST Print View

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:-)

cropped1 photo TitaniumEsbitstove001_zps909fc3a7.jpg

DY
Adventures In Stove Making