Stove to Pot distance for alcohol?

[Gary Dunckel]

I'm going nuts over my patio tests for various MYOG alcohol stove setups. I can't seem to find the optimal distance that the pot should be placed above an open top cat can stove. I get significant soot on the pot (using Klean-Strip green fuel, and even Everclear). I make my windscreens from titanium foil, with various ventilation designs, and with .25"-.5" spacing around the pot. And I'm using the triangular pot supports that I make for you guys.

If someone has a StarLyte stove with the included pot support, would you please measure (1) the diameter and height of the stove itself, and (2) the height of the support above the stove? I assume that Zelph has this concept down.

Input surely will be appreciated!

[Jon Fong]

There are good chances that the soot is caused by the fuel and not the stove to pot gap. Some stove designs are more sensative to the high ethanol content (Klean Strip Green and I am assuming that you are using Everclear 190). A solution could be to water down your fuel by 10% to 15% water. Best wishes – Jon

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[Gary Dunckel]

Thanks, Jon. I've read your prior posts regarding adding a little water to the mix. That will also slow down the boil a bit, right? I'll give it a try. Meanwhile, will someone please measure the Starlyte dimension. Please!

[M B]

Yep, Kleenstrip green leaves NASTY sticky varnish on pot.
Everclear will leave some light soot, more if burning with restricted air (rich).

SLX burns cleanest.

I actually often spike SLX (50/50)with everclear to up the ethanol to maybe 75% or 80% or so, still burns clean, but still lights easier than everclear, and has higher btu value than straight SLX.

The stove to pot distance that works optimally, ie efficient and fast, will likely be one that allows the flame to develop, and cover the most area on the pot bottom, without going up the sides (losing too much heat) . Just look visually.

My open cup burners (tealight) use about 1.125". It depends on how big the flame is, how big the burner cup is, and how large the pot bottom is.

Gotta add that bigger isnt better for the burner. A small tealight cup, works better on a small pot like fosters or SP600, than a large tealight cup. The large tealight cup works great on my evernew 1.3L. Of course I put a piece of bent metal flashing in the cups too to wick more heat into the alcohol, and speed up the burn. Cuts quite a bit of time off.

[Zorg Zumo]

Back when I burned literally gallons of SLX experimenting, I found that > 1" and < 2" was the range for most burner types.

Soot indicates incomplete combustion, which is almost always lack of air and sometimes that can be due to windscreen design – something to remember.

[Gary Dunckel]

Thanks for the comments MB and Zorg. I'll switch back to SLX for another round of testing, as well as look at my windscreen ventilation (I thought I had that down, but maybe not).

[M B]

I have normally about 1/4" – 3/8" gap around pot, with a bunch of 1/4" holes around bottom.
Actually may run a bit rich with limited airflow, I see some orange in there at night. Especially with everclear.

But…it seems more efficient, with better wind protection too.

All I can say is it works for me, and Im satisfied enough not to pursue anything else in the the alcohol realm.

I find it really doesnt get any simpler
or easier to light
or easier to put out
or lighter in weight
or more efficient

[Gary Dunckel]

"I find it really doesnt get any simpler
or easier to light
or easier to put out
or lighter in weight
or more efficient"

What's not to like about that, MB? My windscreens must be a little like yours–about .375" space around the pot, a certain moderate air flow intake on the downwind side, and those moderate yellow flames. I'm getting 7.5 minute boils of 2 C, .75 oz. of alcohol, in 40* F conditions (maybe 8 minutes if it's windy). I can probably learn to live with a sooty pot with those results, but still…the quest is continuous when one is a true dork.

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