Another look at the “Fire Focus 14” ESBIT burner

So given that two stacked ESBIT tabs still have the same top surface area as one tab in the FF 14 then a taller, "narrower-looking" FF 28 chimney with the same size top opening should produce the correct flame.

BUT the flame will be closer to my pot with a taller chimney so I may have to use the Siewinder's Ti stake rods to raise the pot a bit. We'll see.

Back to the drawing & cutting board.

Hiram made a YT video of the Focus Fire 14. His stove is burning a little fast, but I think it is due to his pot stand being 2.25" and not 1.8".

http://youtu.be/ExX6NXhXoko

Jon-

Is 1.8" where I should be seeing the best performance? I did a burn test in my CC Sidewinder already with the FF14 on the ground at a pot distance of 2.25" and the GramCracker at it's standard 1.625" distance. At these heights, I had the GramCracker out perform (in terms of efficiency) the FF14. Here were my results using a 14g ESBIT:

FF14: 63.4F H2O – 46F Ambient – 2.25" Pot Distance
Boil 1 – 8:15 (blown out)
Boil 2 – Water temp at burn out – 120F

GC: 63.4F H2O – 46F Ambient – 1.625" Pot Distance
Boil 1 – 10:08 (blown out)
Boil 2 – Water temp at burn out – 155F

I'm going to try another comparison burn soon with the FF14 tray sitting on top of the GramCracker wing holding base. Hopefully this improves the efficiency….but then I'd have to carry something extra to keep it at that height. :O( My only mistake was not paying attention to the direction the FF14 was facing in relation to the air intake holes in the CC Sidewinder.

In terms of the product itself, I've had my FF14 stay together and flat to the base (I used pliers to firmly flatten the hook-flap)…but the sides of the top opening have deformed a lot. May need a thicker metal or the use of titanium to avoid this. I know the GramCrackers wings have also deformed slightly, but not to the extent of the FF14.

Let me know.

HTH
TIA

-KJ

Warning–this is a bit of a thread drift. As some of you may know, I make custom triangular titanium pot supports for people. Recently a guy asked for one that would work with a real Gram Cracker (not a clone). I need to know what the exact distance is from the ground to the top of a 14 gm. Esbit tabe sitting in the Gram Cracker. Could someone please measure one and post it on this thread? Thanks!

Gary,
I have a 5 to 6 year old (?) Gram Cracker which appears to be the same as the current offering, though no guarantee. The distance from the "ground" to the top of a 14 gm Esbit tab is 1 3/16" to 1 1/4" including the protective foil shield. This is with the large face of the fuel tab in contact with the horizontal surface of the Gram Cracker. When used in the field and after bouncing around in the pack the foil shield becomes imperfect (as does the burner), not exactly flat so I would use the 1 1/4" figure. Perhaps others can verify this number. Hope this helps.

Thanks so much, John. That's what I needed to know. So maybe a 2.5" pot stand will be the right height. By the way, I see you are in Columbia Falls. I was raised in Choteau, on the other side of the Park. Lovely country, my favorite part of the planet.

End of my thread drift.

Making Focus Fire type chimneys is driving me nuts. Getting the exact shape for a larger chimney is not easy and gives me s lot of respect for Jon Fong's work.

Guess I need computer aided scaling ftom the original FF 14 template.
Suggestions where I can find this anyone?

1.8" is what I test at as that is whthe design center for all of my FLAT CAT stove are. It looks like 2.25" is too tall and will give results similar to the G.C. The lower ground to pot distance should give you better fuel efficiency. Best regards,
Jon

Eric,

Give me a few weeks and I will cook up something for you ;-) Jon

1000 4g tabs in a year, wow! Do you buy your esbit in bulk?

I really want to make a permanent switch to it if I can, but its very expensive stuff in Australia. Alcohol is so much cheaper.