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Kevin Burton
(burtonator) - F - M

Locale: norcal
Amount of sparks with 'sealed' hot tent stoves? on 12/20/2012 12:10:36 MST Print View

I'm still confused by the fire issue / potential with hot tents.

If the portion of the stove inside the tent is sealed there shouldn't be much of an issue with sparks. If the front vent is open there is a small risk that a spark could emit and rise in the air but I think this is somewhat small, especially if you're inside the tent at the time.

The other issue is the chimney and if a spark / ember goes through and exits and then falls on the tent.

Could this be mitigated by placing a wire mesh over the top of the chimney so that small particles can not exit?

Embers would then fall back into the stove or get trapped near the top (or break up and exit as smaller particles.

I'd love to go with silnylon or cuben fiber ...

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
re on 12/20/2012 12:20:32 MST Print View

Just make a little fire outside dude, then when you want to go to sleep go into your tent and nice warm down sleeping bag.

That way you eliminate both hypothermia and burning to death from your weekend getaway.

Kevin Burton
(burtonator) - F - M

Locale: norcal
Re: re on 12/20/2012 12:46:27 MST Print View

It's illegal to make a fire outside in Yosemite outside of approved fire pits.

Further, I want to lay in my hammock at night and have it reasonably warm while I'm reading and chilling out.

That, and if I have guest we can chill out and talk in relative warmth.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
A north woods engineer's thoughts. on 12/20/2012 12:56:37 MST Print View

I have some experience with this in the "great-white-hunter" type of tent, and dang!, but it is nice to come back to a tent that you can get to 70-80F quickly. Consider that in Alaska, yeah, we've got cold temps, wind, rain, and snow, but almost more importantly, between Sept 21 and March 21, our days are shorter than yours. 5-8 hours of sunlight plus a few hours of dawn-dusk leaves a lot of dark hours every day so it's much harder to stay warm by staying active outside. Having dry clothes in the morning is also a wonderous thing.

Yes, if your chimney is sealed (even loosely), all the hot gases and sparks will be taken outside. Usually, these tents are canvas and more tolerant of a few sparks. Some background engineering info:

Chimneys can be too short (not enough draft), too narrow (a restriction to flow), too wide (rare, but the heat can be diluted in a big stack and not develop a good draft). A chimney can not be too tall. Taller is always better. You MUST have enough "draft" - negative pressure - inside the stove and chimney to keep hot gases and sparks inside. With good draft, all leaks will leak air INTO the stove/chimney. This is also true during refueling - with good draft, air flow with INTO the refueling door, although obviously a smaller door is better in that regard.

Yes, a wire screen at the outlet will reduce the size of cinders that might get airborne. So too will greater chimney height so cinders are more completely burned when they exit. Also, a taller chimney will give a longer drop time for cinders to cool before possibly landing on the tent.

Ideally, the chimney should be at or above the peak of the ridge line to avoid sparks being caught in a wind-induced eddy.

A few brainstorming ideas:

While your lower stacks of chimney must be steel, you may be able to transition to aluminum for upper sections. Learn to make and break the seams of the ducts and you can nest them inside each other and really save on space.

I'd seriously consider getting stainless for the first section of duct if you will use it a lot. That first section is not only the hottest (duh) but also has the most reactive species in the exhaust gases.

Could you put a "sacrificial" layer on the downwind side of the tent? A thin cotton layer with an air gap to protect the cuben / silnylon below?

You need to leave a awful lot of space around a hot stove to avoid melting clothes, sleeping bags and skin. You'll sleep fewer people inside with the stove fired up. Hence, this works better in large tents than in small.

Test all of this at home first. Cover the cuben/silnylon in old cotton sheets for protection and stretch a painter's 2 mil poly drop clothe over the downwind side to look for potential damage. If there is only one of you, get a free time-lapse app for your phone and set it to record the stack/sparks as you jiggle the stove, start it, refuel it, put trash in, etc.

And, to say it one more time: Whatever the problem, a taller chimney is the first thing to try.

Edited by DavidinKenai on 12/20/2012 13:03:44 MST.

Franco Darioli
(Franco) - M

Locale: Melbourne
Amount of sparks with 'sealed' hot tent stoves? on 12/20/2012 13:48:42 MST Print View

Kevin
I strongly suggest you research this topic (stove heated tents) in the Kifaru forum or just Google TiGoat Vertex/Kifaru Tipi/Seek Outside Tipi.

Dan Durston
(dandydan) - M

Locale: Cascadia
Hot Tents on 12/20/2012 14:25:04 MST Print View

Kevin,

I just got back from a 1-nighter, which was my first time using my TiGoat cylinder stove in my StratoSpire2. So here's a few initial comments on your questions:

- You can buy (or make) a wire mesh cover that goes in the pipe to block larger sparks. Normally these go at the bottom of the pipe. The mesh isn't super fine, but it blocks the bigger stuff. My assumption is that finer mesh would hinder airflow/suction too much.

- I had the stove on for about 5 hours last night and didn't observe any airborne sparks in the tent. I did have one ember 'pop' out of the stove while refilling and land a few inches outside. My assumption is that pretty much everything airborne/floating would be sucked up the chimney even if the door was open. Common practice is to not have the door closely facing anything important. You want to leave a little space for a "hearth".

- The amount of fire debris on the tent was a lot less than I was expected. Only a few small white flakes/dust. My expectation is that anything big enough to pass though the spark arrester and up the chimney, would lack the heat energy to ignite the tent even if it did land on it. It's tough to ignite silnylon without actual flame. If you toss a bit of silnylon on a glowing red hot stove burner, it'll quickly blacken and shrivel, but it won't ignite. I've heard that over time you can get tiny burn holes in your tent, but I've never heard of one igniting.

- I'd be a little more nervous with cuben, just because it melts/shrivels rapidly at extreme heat. If you ever really got the stove pipe cranking insanely and the pipe was sorta close to the cuben, it could melt. Cuben is also pretty expensive for something that will likely get some small spark holes over time. With that said, I was surprised that the silnylon around my stove jack barely got warm. The winter air outside does a good job of keeping the material cool. Most of the time the silnylon around the stove jack/pipe felt cool, and if I really got the stove glowing then a bit of silnylon got a little warm. Certainly far off from any trouble.

Hot Tent 1

Hot Tent 2

Franco Darioli
(Franco) - M

Locale: Melbourne
Amount of sparks with 'sealed' hot tent stoves? on 12/20/2012 14:32:18 MST Print View

Nice Dan
I see you have figured out where to send the colder air... (raised bed area)
That is what I had in mind for my SS2 but not sure if I want to mutilate it because I like it as a rainy weather shelter (without the boot)

Edited by Franco on 12/20/2012 17:13:42 MST.

just Justin Whitson
(ArcturusBear)
a little experience on 12/20/2012 16:34:13 MST Print View

So far, the little experience i have with this, seems to indicate no issues with proper set up and materials. I have a Ti Goat "large" box type stove (made out of titanium) with a Silnylon Ti Goat tent. I've used it a few times and haven't noticed any sparks or over heating of the material around the chimney.

Btw, i did not get this combo for backpacking and hiking, but for any possible SHTF or U.S. collapse type scenario wherein i will be more or less permanently living in the woods (or if i ever happen to become or decide to become "homeless"). However, i have taken it out a few times to test it out in the field--always a good idea with any kind of survival type equipment.

While i'm not SUL, or even really UL (trying to get lighter without spending too much more money), i will note it's not fun carrying around a 4lb tent and a 3lb wood stove even between two people. Definitely doable, but not fun.

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
re: wood stoves on 12/20/2012 20:45:43 MST Print View

tent

Go for it Kevin, it'll work great.

Konrad .
(Konrad1013) - MLife
hot tent on 12/20/2012 23:05:57 MST Print View

awwwww man you guys, now I really really want a hot tent after seeing Dan's and Dave's.

Dan, does the stratospire 2 fly offer enough room and coverage for 2 people while using a wood stove without risking burning someone. Assume that you don't keep any of the gear inside, so it's just 2 people in their respective sleep setups and the wood stove. It looks like you went with the 12" model? Did you have to feed it often? And what length pipe did you pick for the stratospire?

Thanks!

Edited by Konrad1013 on 12/21/2012 09:13:49 MST.

Franco Darioli
(Franco) - M

Locale: Melbourne
Amount of sparks with 'sealed' hot tent stoves? on 12/21/2012 01:45:04 MST Print View

Konrad
The SS2 can hold 4x std size mats undercover.
Here are a couple of shots that may give you a better idea of the space inside.
The white 10L* container is the stove, the ULA Circuit at the back is just for proportion.
Those Expeds are the 6' version.
SS2 stove set upTT SS2 stove set up 2
*about 2.6 US gallons
as it it in those photos , about 10" h,11" deep and 6" , so about the space of a small stove designed for this purpose.
The two rulers are 1' long.
Digging a trench a few inches deep would allow the cold air to go there (away from your sb) and create a seat for you .
You then need to extend your poles a bit further.
You can set up the poles with the snow basket down. To make that easier Henry has designed a pocket to hold the handle in place .
This is the pocket :

Tt handle pocket
(5g)

Edited by Franco on 12/21/2012 14:05:18 MST.

Konrad .
(Konrad1013) - MLife
thanks Franco! on 12/21/2012 03:39:19 MST Print View

Wow, that's a lot of room. I thought it might have been tight, but your pics make it look easy to squeeze in 2 with a stove. Again, I appreciate all the help!

Franco, while I have you, I'm going to pick your brain a bit. I'm currently using a tarptent double rainbow 2010 model. If I pick up the stratospire, the DR will have to go. How is ease of setup in comparison between the 2? And any thoughts on wind stability? I've used my DR in many conditions and I am extremely happy with with it's wind stability and ease of setup. Correct me if I'm wrong, but the stratoshire 2 should have more useable space right?

Thanks again.

Edited by Konrad1013 on 12/21/2012 03:47:35 MST.

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
re: hot tents on 12/21/2012 08:40:57 MST Print View

To be clear, that's a current model Megalight in my above post. It can sleep four, but with a stove 2 is the max, especially as you need space for the wood pile inside. As far as four season utility, the stove jack material is waterproof and it's easy to create a way for the flap over the hole to be held tight. I used webbing tabs and a bungie, Seek Outside uses metal snaps. No problems in the rain at all.

I made my own stove from a Walmart silverware can (http://www.hillpeoplegear.com/FreeResources/Makeawoodstove/tabid/880/Default.aspx). It weighs one pound. The pipe is a 3" stainless job from TiGoat. I put the TiGoat spark arrestor over the top of the pipe (my stove has no damper). You could improvise this from something like a sink strainer, but mind that it does get hot. The limit on finer mesh isn't airflow, it's that creasote would build up so fast.

Being able to dry your socks our during a blizzard is awesome, though it does take some practice and good fuel selection to keep a tiny little stove running well.

Ben Wortman
(bwortman)

Locale: Nebraska
Heat is good on 12/21/2012 09:07:19 MST Print View

I used a couple stoves in MYOG tipi's/mids. It works really well. I think the key is to have the stove pipe a few inches above the top of your shelter. I also used a stove that had a mesh screen down by the stove where the pipe attaches. I have had a few small burn holes in 1.1oz silnylon before I used screens, but they are easy to fix. I have not had any since installing teh screens.

Once you have a hot tent setup in winter, you will wonder how you ever lived without it.

kevin timm
(ktimm) - M

Locale: Colorado (SeekOutside)
Tips on 12/21/2012 09:53:05 MST Print View

You can put a spark arrestor on the outside but you need to be able to get to it if it clogs. You can also put one on the inside near the stove which is less likely to get clogged (although it still can if you run really bad wood, or for very long periods of time like 20 hours continuous). Having the stove pipe taller will minimize spark holes but it is a trade off and to tall of a pipe can be a problem in high winds. You can get spark holes in tents, but then again you can get spark holes in tents from a campfire outside as well (talking silnylon tents here). I've seen it happen both ways, a wind shift on a nearby campfire is worse than a controlled burn inside as far as spark holes. Spark holes on silnylon is easiest repaired with clear Silicone caulk.

There is a big difference in warmth between a campfire and a stove, especially when the days are short. In November, I camped in a high basin, and we did not take a stove. We could barely get warm enough with a campfire. It was a struggle. In Dec I camped in a 6 man with a stove. It snowed 15" overnight, and temps were pretty low as well. In the tent, I actually had my socks off for awhile and was down to regular clothes. They can make a tent a type of warm you will not get from a campfire. A strange thing happened that night, that it started snowing and made essentially an insulating layer on the tent. At 2 am , it must have still been 50 inside when it was only about 15 outside.

The choice of wood and how you burn the stove will have a lot to do with sparks. Some wood just doesn't burn as clean.

As Dave said, usually I cut capacity in half when using a stove / winter gear etc. It does take up more room.

It's hard to justify a stove on a peer weight basis, although the stoves can be very light. It is easier to justify the stove on having dry gear, comfort and a good nights rest. I'm sure it's easier to carry the extra 3 lbs on a day when you are well rested, vs one you spent shivering all night. We do have one stove we have prototyped that weighs less than 8 ounces without the pipe. That one is an easy justification, and I will carry without problems during shoulder seasons. In the end, I think a campfire, for all their glory is more work at times than a stove as well.

Kevin Burton
(burtonator) - F - M

Locale: norcal
Re: Tips on 12/21/2012 11:13:28 MST Print View

The stove +larger tarp is more weight but:

- you can use a pulk which helps mitigate this a bit. The pulk also means you can sled down large hills if it's big enough and in theory could save a bunch of time in your return or if you're doing a lot of hills

- You're spending LOTS of time inside your shelter - it might as well be comfortable. It will also allow you to dry your clothes and could really be a life saver in an emergency.

- Since you're hiking a limited amount of time per day you have more time to recover. A few pounds isn't going to kill you.

- if you are going with multiple buddies you can relax and chat inside your shelter.

- you don't have to bundle up like a yeti inside your hammock. You can just sit it your hammock and read :)

Franco Darioli
(Franco) - M

Locale: Melbourne
Amount of sparks with 'sealed' hot tent stoves? on 12/21/2012 12:54:01 MST Print View

Well I'm glad you hot tents fans have come out in force.
Obviously not UL but it can be a lot more fun and just a different way of doing things.
Thanks David Chenault for the link.
I made a smaller version of that (from a water pitcher) and another using bain marie trays but I might just try again with something else.
(I have the pipe and bits from TiGoat)
Konrad I'll send you a PM.

kevin timm
(ktimm) - M

Locale: Colorado (SeekOutside)
That pretty much sums it ip on 12/21/2012 12:59:33 MST Print View

When the days start getting short and you are in your tent a lot the stove is the way to go. It also makes waking a lot easier as well. Just light the stove from the comfort of your sleeping bag, wait 10 minutes and get up. I did a trip in October with the Lil bug out and some friends. After the windy days and cold temps we were more than happy to sit around the stove and chat for a few hours. Certain stoves you can also cook on as well, so that helps offset the weight.

Konrad .
(Konrad1013) - MLife
thanks on 12/21/2012 14:27:29 MST Print View

Franco, thanks for the PM! I'm pretty much set on grabbing a stratospire now. Thanks ;)

I agree, a hot tent is definitely not UL, and the weight of the stove boot (3-4oz) + actual stove (1-2lbs) would be better spent on more down in my sleeping bag if I were strictly concerned with keeping warm...hell, with that much weight gain, I could easily get a -30 degree bag. But it's the fun of it all that's really clicking with me. I can recall some trips where I got to my campsite at 4pm and thought, "Hmm 30 mins left of day light,well sh*t, I guess it's time setup and go to bed?" One can only sleep 14 hours per day on a trip so many times. At least this will keep me awake for couple more hours, plus maybe like Dan, it'll give me an excuse to drag my significant other out there when temperatures are brutal.

Anyone feel like talking tools? If this whole day dream of mine comes true, I plan on bringing either my 2-3oz fixed blade (either a bark river bravo necker 2 or a ESEE candiru) but now I'm thinking whether or not I need a lightweight saw (something like what QiWiz offers). I have a small 2 ounce japanese flush cut pull saw already, but it's a bit small. I don't want to get into hatchet/axe territory since I think it's overkill for size of wood I would feed into such a small ti stove.

Edited by Konrad1013 on 12/21/2012 14:28:19 MST.

kevin timm
(ktimm) - M

Locale: Colorado (SeekOutside)
Tools on 12/21/2012 14:50:20 MST Print View

Around here at least, I rarely carry any additional tools if I am using a small stove. Instead I just find dead sticks / branches etc. If the stove is a larger type where it can burn a couple hours on a good size piece of wood, then I consider some sort of tool. It's usually my leatherman and a knife for batoning wood and if need be and I only cut a few bigger pieces and still use a variety of sticks. For a longer term camp, where you were going to stay put for a few days, some good tools would be worth it. The tools itself could be a good blog post. I've had customers mention their favorites many times.