Multiple Tealights

A friend of mine (he will remain anon. unless he chooses to disclose himself) is crazy about tealight stoves. Not sure why you say the heat output is "a great deal" less.
But in any case, because the tealight can only hold half an ounce of alcohol — it frequently fails to bring 2 cups of water to a complete boil — in which case, you have to reload.

As for burning two tealights simultaneously, you can probably get away with that if you use a wide pot. However, for narrower solo pots like the Firelite 550 — some of the flames will likely just go up the sides of the pot — wasted.

I myself am still on a quest to find that elusive one-ounce tealight — one that is the same diameter or just a little bit wider than the half-ounce, but taller.

Well, I don't know about the heat output actually, I haven't done any testing of my own, I've just gotten that impression from people . . . not true? Maybe I was taking the fact that it often doesn't boil to mean less heat output, but it makes sense that it could just be because of lower fuel capacity.

When I stick two tealights together (or three or four! :D), the flames want to stick together. I'm guessing the low pressure flames suck each other together, I dunno I'm not informed about how that works by any means. But the result of sticking tealights side by side is a surprisingly centralized flame, not spread out, which makes me think it could be a viable solution.

Of course, I'm cooking in a MSR Titan pot, .85L, not a Heiny or Snow Peak cup. Wider pot ==> flame spread less worrisome.

Hello, my name is Jason and I'm Ben's "anon" friend. Chorus in monotone: "Hi Jason".

OK, now that we got that out of the way…Well, Ben is right about one thing: you're idea is a good one but will only work well with wider pots. Plus, do you really want to mess around with filling 2 stoves and positioning them just right?

If you want an adjustable-alcohol-stove system to use Tinny's baking method yet still be able to boil, why don't you try the ISOfly or Blackfly: http://www.minibulldesign.com/fs2.htm

That might fit the bill. Or, if you're willing to go somewhat heavier, then maybe a Brasslight that offers both simmer and boil modes is for you.

Ben or Jason or anyone,

Why can't one just cut off the bottom of a juice can and make a pseudo tealight stove of the size and volume desired? Is there something special about the proportions of the tealight "tin" that makes for a better stove?

-Mark

Yeah I was also enamored with the IsoFly and loved the video demo on Tinny's site, so I got one. But honestly and surprisingly, I find the thing to be finnicky. The water jacket is fussy to fill and empty, as is getting excess alcohol out of the stove. In my kitchen test the thing overheated a good deal faster than the ~20 minutes that Tinny suggested in the video.

The biggest problem, though, is that the fiberglass wick becomes burnt and brittle a lot more quickly than I would have imagined. One 20-minute burn on the high 3/4"-wick setting made the wicks so crispy that when I tried to push them into a lower setting, they both broke, and one of them right where it inserts into the stove, in such a way that I couldn't remove what was left inside. So now I have several inches of unused wick inside the stove, and it gets in the way when I try to insert replacement pieces.

If the wicks burn so brittle so quickly, I think I'll need to be replacing them all the time. Lame.

Have I missed something?

Anyway, that's a side issue, and I don't mean to flame Tinny at all because frankly I think the guy's a bit of a genius and his designs are superb. But so far I've had a disappointing experience with the IsoFly, and so this post is sort of a reaction to that . . . wanting to move to something a lot simpler, with less things to break or fuzz out.

I found that Sunkist prune juice cans, in the 5.5oz. size, are about half the weight of the typical 5.5oz. V-8 juice can. That would allow one to make just about any volume "Tealite" stove you might desire. Of course you must find some use for the prune juice… and if you're of a certain age will necessarily get knowing looks from the cute young checker.

Mark:

Jason had explained this to me once.

The aluminum container of a tea light candle is significantly thinner than a juice can. This means that very little fuel (and time) is wasted in heating up the stove and fuel (priming). As a comparison, I have a tin coffee scoop that holds exactly one ounce and is the perfect size for my narrow pot. However, because the scoop metal is thicker, it also takes more fuel and time to prime.

I'll wager that the priming time (and fuel used) for an aluminum can versus tealight holder of the same volume is insignificant.

I've tried it with the 1oz coffee scoop — at home where it's not even that cold — and the difference is about 30 seconds. Knowing how "anal" some of us are, I bet that's significant to some — if not to others.

Ian,

your isofly wicks are to high. I had the same problem. now I lower them down just a little and remember to wet the wick with ALC before lighting. After a few wicks I got it figured out. I now really like the stove, it doesn't over heat as much because the wicks are not burning the ALC does. if you see your wick starting to get that burnt look you might be out of fuel. My biggest complaint is when it runs out the wicks still burn and get crispy. Since you can return the fuel to the bottle I usually fill the stove full and that takes care of the problem. After a few trips I now love my Isofly, but at first I had the same sediment as you.

Tommy

Ben,

Is your "tin" 1 oz coffee scoop aluminum or steel? I believe the heat conductivity of aluminum is something like 3 time better than iron. Also I don't have a micrometer, but I doubt the thin aluminum of your average juice can is much thicker than a tealight. I guess I will have to acquire a tealight to test. And of course there is an extra half ounce of alcohol in a 1oz container that has to be heated. Hmmm — got me thinking…

-Mark

Mark:

The aluminum on a tea light really is much thinner than a tin can.

Ben,

Thanks! I'm going to try to pick up a tealight this weekend.

-Mark

Ok Ben, I was wrong. The tealight is thinner aluminum than the juice cans.

I picked up 50 of those little guys for $2 at Walmart this a.m. Took one and heated up the "tin" with a hairdryer. Popped the candle out and then tried to weigh it. Less than a gram is all I can say, it wouldn't register on my scale. So then I tested it out.

Using my usual 1:1 isopropyl:denatured ethanol mix and filling the tealight to the brim I was able to get 2 cups of 60 F tap water in a Heineken pot to 202 F in about 11 min. Amazing! Since this "stove" only holds about 11 or 12 ml. (Of course this was in perfect windless conditions in my kitchen)

Very impressive. Now I see why you and Jason like these stoves.

-Mark

Mark:

IMO, it's the stuff that's "almost perfect" that is the most frustrating…

As you now know, the aluminum container of a tea light stove is just about perfect as an alcohol stove — except for its meager half-ounce volume. With winds blowing and/or colder temps, half an ounce of fuel just isn't enough.

When I asked around the various forums about larger tea lights that use the same thin aluminum material — and ideally the same diameter or just a tad wider but deeper — some folks tell me that "they're everywhere". But I can't find any — and when I asked them to look — suddenly, no one could come up with one! :(

And so the search for the holy grail — the one-ounce tea light candle — continues…

I was actually at my friend's apartment the other night and noticed some tealights on his coffee table that were really fat, maybe 2-3x the diameter of a typical tealight, and maybe a cm taller or something. He said he picked them up at IKEA for about $0.30 apiece.

After explaining my interest he just gave me one to play with, and I filled and lit it at home like a normal tealight. What I discovered was interesting–I think. The flame that came from this bigger badder tealight flickered and coughed like crazy–very turbulent. I read that when flames do this it's usually because of a dearth of oxygen. By contrast, the normal small tealights that we've been talking about produce a very steady, even flame. At least, that's true in my observation.

Note that I was burning this fatter tealight on my stovetop in my kitchen with no windscreen of any kind. Now, I'm definitely not an expert on this topic, as I'm just getting into stoves, but I wondered why this flame could be thirsty for oxygen. The guess I can hazard is that maybe the flame is just so wide that the combustion happening in the middle of the alcohol pool is denied oxygen because the peripheral burn consumes too much. Essentially the flame is too wide for its own good, right? Maybe this is the same idea that compelled the designers of the Zip Stove (wood burner) to use a powered fan to force oxygen into the fire. Maybe a tealight this big just can't feed itself enough oxygen on its own. This seems like an un-scientific analysis . . . but it could be.

Would someone more qualified like to suggest something?

Ian,

In my experiments with paraffin and beeswax stoves there is definitely a point at which the flame is "too wide for its own good." Roger Caffin is the BPL stove guy and he has mentioned the oxygen issue repeatedly on these forums.

Ben,

Ian and you are right I think. The Bigger Tealight needs to be deeper, but probably not much wider. I think the diameter of the stove is key to why it works so well with small pots. You know, back in the day, film canisters came in small aluminum cans. (Film was an ancient way of capturing photographs:-) Anyway, they were approximately the diameter of the tealight I think, just deeper. They wouldn't be quite as light, but maybe they would work if I can find one. Or what about making one out of foil? Could be even lighter. Anyone try this?

-Mark

Like I said, I'm new to stoves and stovemaking, but I don't see why you couldn't just take some heavy duty Al foil (or maybe a tad bit stiffer, like this stuff they call tooling foil maybe?) and cut it into a cylinder of the desired dimensions. Then just make an aluminum floor and crimp up edges to accept–either on the inside or the outside–the cylinder sidewall you just made. Sealing it could be as easy as JB Weld, true or false?

Honestly I'm not sure why this hasn't been done already. Maybe the JB weld is heavy enough to neutralize the weight advantage of a tealight? Like I said, I'm a noob right now . . . :-D

Good joke about this thing they call "film"

Actually, I've tried making my own 1oz tea light with aluminum foil. Starting with a piece of foil folded over 2 or 3 times, I slowly and carefully pushed the center into a 1/2-oz. tea light, then slowly press down against the floor all around, then molded the walls to twice the height of the tea light all around — then folded over and tucked to the bottom of the tea light on the outside. No holes, no cutting, and therefore no leaks.

Problem is that after a few uses, the flame and heat will degrade the foil — and burn through! Maybe tooling foil might work…

An extension could be made to an existing tealight holder with 1. HD foil,
2. foil tape or
3. cutting the bottom out of one tealight holder and JB welding it to another.

Has anyone tried lathing a 1oz tealight stove out of a piece of aluminium? Could be a possibility, though I can imagine it could be difficult to get the walls thin enough to get the thermal mass down, without destroying the stove on the lathe.

I will ask a couple of turners I know about it.

Having run a lathe a bunch myself I don't think I could do it without destroying the stove by the time you got it thin enough. Maybe a better machinist than me but I'm not optimistic. Stuff like tea lights are probably stamped out in big presses like how we make aluminum soft drink cans (I work for a packaging company).

The closest you'll probably get is cutting down very small beverage containers like a starbucks doubleshot etc.

Edit: Oh yea the cost to machine something like that would be out of this world compared to anything people would want to spend too.

Benjamin,

I have the normal TL stove in front of me that measures:

14.5 mm tall
37 mm wide

or

9/16" tall
1 1/2" wide

I have some from Whole Foods (sold as 10-Five Hour Tealight Candles, 365 Brand) that measure:

17.5 mm tall
39 mm wide

or

11/16" tall
1 17/32" wide

The smaller TL will fit inside the larger one very easy. I can send you a couple if you want to try them. I have no way to really measure the exact capacity.

Jon