tea light stove

I tried using a tea light stove yesterday, and I was not impressed. I used denatured alcohol filled all the way to the top. It burned for 14 minutes, and the water never boiled. I am in Phoenix, elevation is around 1500 feet. The ambient temperature was approximately 60 F. The stove was in my garage and out of the wind. The water quantity was 24 oz., and the water temperature was about 70 F. Is this the performance that can be expected with the tea light stove, or was there something I was doing wrong.

Craig

I've tried a tea light as well with similar results. The problem is that the tea light doesn't hold enough alcohol. At least not enough to boil 16 oz of water in my experiment. No way you can boil 24 oz with it. It might be fine to boil 1 cup of water.

It's also not a super efficient stove, basically it just holds a puddle of alcohol that is burning. But some people would argue that the lack of efficiency is made up for by the fact that it's so light. So you can carry a bit more fuel and still be ahead from a weight perspective. But you also have to limit yourself to meals that require only 1 cup of hot water.

To bring ~1.5 pounds of water to 210F from 70F takes 210 BTU.
95% ethanol + 5% methanol = 12550 x .95 + 10200 x .05 = 12432 BTU/pound
12432 BTU/pound / 19.5 fl.oz./pound = 638 BTU per fluid ounce
A tealight holds about 0.5 fluid ounce = 317 BTU

So your stove would need to be 210/317 = 66% efficient for that to work. Depends on ambient temperature, and wind, but to get 60% you would need a good windscreen and a good match of stove to pot size, and not too cold of a day. If you are getting say 40% efficiency with an ambient temp of 70F, or 140F below boiling point, then at 30F you should get to 170F at the same efficiency. If you still want to get to boiling you would need about (170/140)^2 or about 50% more fuel.

This write-up by the Rock is pretty good...
http://hikinghq.net/sgt_stove/ion_stove.html

You could try sticking with the tealight, but maybe add a wick. A wind screen should help also, even though its only 60F, because you are trying to get to 210F. Try a wind screen, and vary the gap. Also try a beverage can pot to see if its the thickness of your pot that's killing you.

Did you have a windscreen? I've used a tea light stove with good success. Boiled 1 1/2 cups of water under 10 minutes...closer to 7-8 with no problems. It may not be as efficient as a cat stove with all the jets and such, but it works for my needs.

searscr-

As others have posted, 24 oz of water is too much quantity for a tea light stove to heat, just as a 4 cylinder car can't be expected to haul a large load of freight. Also, a windscreen and the pot make a big difference, as menitoned already. Two things I did not see anyone bring up: The surface on which the stove sits and the distance between the stove and pot.

I use a piece of foil-wrapped corrugated cardboard under alcohol stoves to both protect the surface and to insulate the stove from it. The smaller the stove and quantity of alcohol, the more the surface can affect the stove's perfomance. Think of any cold rock, metal table top, or a cement floor as a giant heat sink.

Also, there are optimal distances for getting the most heat transferred from a stove to pot. Make sure your flame is reaching the bottom of your pot, but not traveling up the side and around it. You should be able to find a good bit written about this.

I think you said you used isopropyl alcohol. It may not throw quite as many btu's as ethanol or methanol, but the form of alcohol is probably your biggest issue. If you are using common rubbing alcohol, it is normally 70% alcohol and 30% water. If your alky is from the "Dollar Store," it may be only 50% strength, in which case I'm a bit surprised you could get it to light. If you are in a drug store (rather than convenience store), you probably can find 90% isopropyl. It burns hotter and more easily, but isopropyl does throw a lot of soot and stinks.

To test gear, I have buried my alcohol bottle in a snow bank overnight, using that fuel to fire a tealight stove, boiling about 12 oz of water in a beer can pot. This could have been 10 years ago, so I don't remember the time, but IIRC, it was about 17 degrees outside, the tap water was very cold, and I just stuck the stove, windscreen and all, just outside my back door.

I also put two candle cups together, much like some of the soda can stoves. I have not tested one of these against an open cup to see how much this helps.

There was a gal who couldn't get Esbit to boil water in her back yard. With some questioning, we (on another list) found out she not only used no windscreen, she was using a Revereware kitchen pot. A lot of factors come into play when we talk gear.

Regards,

CamperMom

I noticed on one of my vacations where I took my Esbit stove and fuel and on a particularly windy day, it took a long time to boil the water. I was using some foil as a windscreen and my pot and stove were on a rock with a very irregular surface, so the wind I am sure played havoc with the heat getting transferred to the pot of water, since I had quicker boiling times on calmer days so I can imagine with the lower heat output of alcohol, that with no windscreen it would have been impossible to get that large amount of water to boil with a small amount of fuel.

I agree. Using something as small as a tea light for a stove is on the extreme of ultra light and if conditions aren't right you could experience trouble. My last trip I used a pop can stove with very good results. But I had perfect conditions to use it in. I have now fitted a cone shaped windscreen, a base insulator and using two tent stakes to hold the pot at the right height from the flame, I now use my heavier Trangia. That's about as lightweight as I'm willing to go from now on.

Thank you for the help. I was using a 24 oz beer can pot with the bottom painted black. I admittedly did not use a wind screen, I was using denatured alcohol, and I was on a concrete slab. The slab temperature was lower than the ambient. I plan to test it again. This time I will use HEET as a fuel, a ground insulator, and windscreen. I will let you know what happens.

Craig

A wick, in addition to the other suggestions, will improve tea light performance by producing faster burn time. The problem with a slow burner is that the pot loses heat even as you heat it, and the rate of heat loss increases with the temperature of the pot. If you heat it too slowly it will reach a temperature at which heat is going out as fast as heat is going in. The wick gives a faster burn by increasing the surface area of the alcohol available to burn.

Just don't use too much wick because it takes up space in the already limited tea light.

You can find larger tea lights that will hold a full ounce. They are the same thin aluminum as the regular votive size.

I used the Esbit stove for the base of my tea light and pot stand, so I knew the distance of flame to pot would work. The pot was from Anti Gravity but I have also used my Snowpeak pot that is round and short, not the taller sets. I usually don't need to boil much water.

Or you could try a redbull can...

Spock
quote
The problem with a slow burner is that the pot loses heat even as you heat it, and the rate of heat loss increases with the temperature of the pot. If you heat it too slowly it will reach a temperature at which heat is going out as fast as heat is going in.
end quote ___________________________________

Thanks for that observation. I think a lot of people ignore the fact that under real winter usage, a small heat source will simply not work because its small amount of heat can radiate away before it warms anything. A huge powerful force like a 15,000 btu stove is best for winter because the heat radiated away from the pan is small compared to the incoming heat.

Also for melting snow you need a lot more energy than to boil 70 degree water. Try a cup of water with half ice. Now take it out in a cold wind and try it.

One winter we took a whisperlite and forgot the windscreen. It took 45 minutes to get half a liter of warm water from snow. Do not underestimate the amount of heat loss to cold wind. The next winter we started carrying an XGK but now I just carry a coleman Xtreme becasue the instant on and off with no priming means I can cook inside my tent with it, and I do. I can fire up my Bibler hanging stove in the tent and boil water to create a steam sauna in the bibler tent and the heat just pushes all of the moisture out of the toddtex (goretex) tent while I bask in the heat. You do have to be considerate of ventilation and carbon monoxide and flame in a tent. You do not want your air mattress or down gear to touch a red hot stove. <img src="/forums/images/graemlins/tongue.gif" alt="" />

Jim YMMV <img src="/forums/images/graemlins/cool.gif" alt="" />

I followed Jason Klass' instructions and mine worked fine. I used a heiny pot - not sure it that helped. It did not come to a rolling boil. With that type stove you may have to heat treated water to near boiling and then add it to your food. You do not have to get a ''boil'' to cook food or make coffee.

My second attempt worked better. This time I used a wind screen, I placed the stove on a slightly warmer surface, I used only sixteen fluid ounces, and I used HEET. My results: I got the water to come to a rolling boil in ten minutes, however, I had to refill the stove after eight minutes. Even with the refuel I only used a little more than one fluid ounce. Thank you all for your help.

Craig

I'm glad to hear things are working better for you and that we were able to help!

CamperMom