Chimney Shapes and a Roaring Fire Getting Too Hot

Well I see 2 problems right off, your using way too much fuel for the size of the device, and the chimney should not decrease in size, it should be uniform...... If you want to throttle the heat, you might try a slower burning fuel, such as coal or charcoal.......

I very much appreciate your post, thank you. However this was designed and used by an online friend I have nothing to do with it other than, as today post a question hoping to get some resolution. If would be interesting to see or know the reasons you say what you have? Take care bb

With respect to you and your friend, I would not have fire in a tent. I have lived through two tent fires myself, and helped to pull the melted sleeping bag off another friend who thought candles were the proper way to illuminate her sleeping area.

Therefore, I cannot in good conscience suggest a safe way to have a fireplace inside a nylon tent. You boil water in a kettle placed over the outdoor fire, and fill the hot water bottle! You either fight nature or live along side it...if you fight nature, you WILL lose eventually.

But just curious, why would you (or your friend) want to re-invent the wood stove? There have been stoves built for centuries for canvas covered shelters.

Canadians are no strangers to the concept, in the old days of prospecting in the Canadian North, tents with stoves in them were quite common. Also army tents (as in the TV show M.A.S.H.) have had cooking stoves in them. Here are some links you might find useful.

ammo can stove

oil barrel stove

home made stove for tent

Hi Yusef1, Thanks for your thoughts and for the links. This man I call a friend is but only online, we live 6000 miles apart any there is no way he is going to do this again actually in a tent again, but he knows of people who think they can outsmart the laws of physics so thought he would try, not expecting what happened but also wanting to shut those up whom as he said to me today, have mots of ideas but nothing to back them up! I absolutely agree with you on fires and fabric they do not mix. He did a test two days ago where he still had the chimney and fireplace, and wanted if nothing else to show what happened in his tent, but I must point out that the very first fire was 'a success', and it and the second fire were made with only part of the tent cover, which was fireproof, actually forming any kind of shelter, this last test was entirely on how what happened in the second fire where it burned out of control even with a small amount of kindling, and this was done in the frame of the tent, no material, no cloth, he wanted to show how dangerous it was I think, plus try to redo what happened using the chimney only, and this time he let the fire get more out of control because it was in the middle of his garden, and the chimney just melted and collapsed. So it was done as a warning. I think now he might go the safe route and use a camp fire as everyone else does! Nevertheless, and not wanting to build another one in a tent he is building no more, but I thought without giving any advice to him, that it was an idea that perhaps could work but really fires in portable living areas should only be built with a completely safe steel surround, but I just want to ask those who I know can go away and work it all out on paper, and in all probability come back to me saying it is not possible! There is no danger in me ever trying it as I am an invalid with absolutely no tools or space to work in, but I would be interested in the theory only. Not for me to carry out any instructions, just to find out the reason this did not work, NOT to go on and build another! Take care bb

Hi, BB.Never go camping with your on-line friend. I couldn't bear to watch the video, I was laughing too much. I have relatives like that.

More imagination than brains.I have to second the "no fires in tents" vote. That's insane. Maybe a small catalytic heater, at most.

Otherwise build a REAL fire outside the tent.

Cheers!

Yes, too much wood too. Use lots less and feed more frequently.

Hi lyn, I absolutely agree with you and as I have said I am an invalid anyway so there is no danger of me going anywhere with my 'ONLINE FRIEND AT ALL', as we are 6000 miles apart. Take care bb

I agree with the comments about the fuel. Using lots of bits of finely-cut very dry wood is like setting fire to the brushwood in a forest; the inevitable consequence is a lot of huge flames. It would be better to use as small an amount of kindling as possible to start some larger chunks - much less surface area and much slower burning.

Hi John, I have no plans EVER to do anything similar, and I can't recall if I said so but in one reply to a friend in another country in Europe not the UK I said that same thing that the type of thing on the combustion in the chimney sound like the wood was like a mini forest fire creating its own weather! I thank you for your reply, and its nice to know my friends are there, and again as I say I just want to know why his design went up out of control. Take care and thanks bb

Wow, fire in a tent. Kind of reminds me of a little saying:

Build a man a fire and he will be warm for the night.

Set a man on fire and he will be warm for life.

It's good to see a picture of this. I find the idea of lighting a fire in a tent a little worrisome. Even if the tent is fire retardant, other items will most likely not be and there is always the danger of asphyxiation.

WOW, I'm glad I never asked you for a fish.

Or a light.

Hi Anonymous-Hero, What can I say other than I agree with you! I thank you for your input and please realise it will not happen to him again and certainly not to me as I am an invalid so for sure will not go camping! Take care bb

I would make sure the chimney is insulated for about a foot either side of where it passes through the tent. I don't know if fiberglass can withstand the temperature, but a fireplace shop can give you good ideas. Burn only modest amounts of fuel.

Hi Tornado, Many thanks on getting back to me, and btw, you know I hope that I work only in facts and cant and would never try this! ;-) I take on your suggestion but think my friend had enough of a scare to do this again. But please allow me to say one thing, my friend wants nothing more to do with this type of fire, though to be fair everything was fireproof, until when reconstruction it can be seen that the chimney seems to be drawing air in through itself, and I know when this fire happened the fire time it almost set him on fire he had to answer over 1000 replies from those who were telling him "you do not do it like that, but like this"! so he has his life busy enough without having to fend of other theories on what happened, so I am asking here that no one get in touch with my friend he has had it 'up to here'! Please take no insult on anything I have said, and obvious thanks for the very sensible idea of a complete surrounding metal around the fireplace near and hopefully not in a tent! Take care, and thanks bb

Less wood, and a way to dampen the air supply. He could also remove the tent completely, and cook some burgers.

Last year a family in the UK all died of carbon monoxide poisoning when a charcoal burger grill llike this one was left overnight to cool inside the flap of a tent. The media ran a campaign for a few days warning campers not to have charcoal grills inside the tent and then went quiet because it was at the end of the camping season. I wonder if the campaign will be continued at start of this camping season when it is most needed? I am something of a cynic when it comes to the usefulness of the UK press.

Hi, And thanks for the reply and very useful info. I know when he was building this he thought he was leaving gaps round the edge of the tent, and he decided to build the chimney to ironically stop any gas from free flowing into the tent. And the very first time he used it when the chimney came to just above the cooking area he had no problems. Though that may have been more by luck? I live in the UK and do not have a radio of TV and I never came across this news where the whole family died, thats terrible. I recently got a Carbon Monoxide warning thing for my flat as I use gas to cook. The trouble is with any gas it is invisible until someone awakes and find a brother or friend dead. Do you know if this was for sure a charcoal grill and whether the same dangerous gases would come off wood if let to burn down in a confined space? Many thanks for the info once again. Take care bb

Apparently it is not all that uncommon. UK, Shropshire May 2012, 14 year old girl died, Hampshire April 2012, 6 year old girl died, Gwynedd August 2011, 34 year old woman died, USA Tennessee September 2011, 3men & 2 women died. The US Consumer Product Safety Commission reports that annually there are 30 deaths and 450 injuries caused by CO poisoning but those figures will include more than just barbecue deaths.

The 3 UK fatalities listed above were all charcoal briquette barbecues, but lump-wood charcoal emits CO, therefore I presume so does raw wood. The difference is that people are less knowledgeable and so less cautious of charcoal which burns slowly and smolders for a long time after you have finished cooking, giving more time for the CO to kill. In your scenario your friend is attempting to replicate these long slow burn conditions.

Thanks for making me aware of this: it's a danger I never would have contemplated.

Here's one

http://www.guardian.co.uk/uk/2013/jan/17/tent-barbecue-death-carbon-monoxide

And, a link to one of the warning articles.

http://www.campingandcaravanningclub.co.uk/helpandadvice/camping-safety/carbon-monoxide-poisoning/

Hi Randall, And many thanks for the warnings. I do not thing my friend thought much about the CO because he estimated there was enough gaps around to blow any nasty stuff out. Can I piggy-back your reply post to say and ask for any technical details on the shapes and stuff on chimneys that make one a 'forge' and another a safe normal fire. If anyone can supply these details I would be most appreciative. The consensus is that the tiny bits of split wood was to much too soon, but at some time or other it was going to burn like it did in this video. The other thing is some say this is a forge not a fire, but what is the difference mechanically? He has had so many You Tube members write saying things like "I would never have done that" or "you should have done this"! So much so after going through 1000 comments he felt like he had been in a boxing match and had gotten beaten up side the head you know, so that was the reason I put the question, to save him more of the YOU DONT DO IT LIKE THAT brigade. I home those here and new members can help in a technical way to explain this so I can then explain it to my friend. Even though he may never do this again, and I think that would be the right choice actually, he and I still want to know WHY it burned like this backed up with specs if possible, OK? I thank those who have so far been very helpful. Take care bb

I watched the video and I can see a load of problems with the design.

Here is a link for everyone. Tent fireplace burn down.

First your material may be fire resistant but it is in no way airtight or fireproof.

Second in the video I see lots of air gap around the bottom of the canvas material between it and the metal base. That's where the fire is getting most of its air.

Third your chimney design is grossly over sized.

If it was me I would redesign the fire chamber area that the grill grid is in to be all metal and to have an actual air tight seal to the base.

From there I would reduce the chimney down to around 40 - 50 mm in dia at most and make that of a dual or triple walled metal design like normal fireplaces and pellet burner stoves use. Then have it extend a few hundred mm or more over the top of the tent.

last I would add a flapper or vent restriction system to the intake tube so that if needed all the air flow can be shut down. If your fire is still burning with that fully closed you still have air leaks coming from someplace else.

Hi tcmtech, No insult here just friendly stuff, but to point out that in fact the material he used for his fireproof tent, was and is in every way fireproof, not just resistant. It is the same material used for and by scientists testing , those who are daft enough to test anything near a Volcano, and the same stuff as the suits used in Foundry's. It is the chimney itself that was less than fireproof! He took no film of what happened when the second of the fires to test his ideas happened as he was a little busy putting it out. So it was the set-up in his garden with absolutely no fabric nearby other than the one he was testing that is the chimney material. Thanks and I very much appreciate your help. Take care bb

Hi tcmtech, Not sure why but I ended up signing off with out reading the rest of your kind reply, forgive me. I do not know enough about fire which is why I posted this question, not to redesign but more to find out why this happened. I would be grateful for any ideas of why you said what you did. I had asked if a controllable flapper could be inserted and he said he did not want that, but I do not have enough knowledge to say anything about the size or shape of the chimney. I am looking for some evidence of either the correct design, or what happened and what caused it. I do realise the material around the bottom was far from a good fit, but I think this was done as more of a "lets try it to see if this works any better" scenario than having anything worked out on paper. I think it could have happened for the same reason holding a sheet of paper over the front of a small home fireplace does, which is to induce the fire to draw from below the grate making sure the kindling is alight, and that is to use this analogy to replace the paper in front of the fire with the extra piece of carbon fibre cloth to cover the entire cooking and grate area. Take care bb

Besides the obvious dangers you have to think ahead. A good gust of wind with a fire going in a tent, well, maybe you see my point. Where I live we get gusts up to 80 mph and some more than that, and there is no warning. Advise your freind to be careful and maybe switch to an electric blanket.

HI spaceracer, I thank you for your concern and actually think by what was shown on the video of the original fore burning out of control, that is he was filming for maybe 45 minutes as he set things up and lit the fire and about 2 minutes afterward, he must have stopped the video while he took his stuff like knives and bags cooking utensils etc out, and was extremely upset when the video started again after maybe a 20 minutes break. I think this scared him enough not to think of an 'In-Tend' means of making fire unless as one can get now the Tent is 3 metres round like a TeePee and the fire is in the centre. He is very very angry with himself at I think not having tested it, the same way he shot the film you saw with nothing around to get in the way or to cause danger. Thank you. take care bb

A fire inside an igloo is the only thing I can think of that would be less sensible.

Hi, And thanks for the input. A fire in an Igloo not sensible? How on earth are they supposed to get warm enough to make kids? Take care bb

Hi and thank for the reply. Thanks this is a pretty good idea! I meant to say it wont be anymore because the other fire with the great looking chimney burned completely. It was held in shape I believe by thin steel flats like packaging steel wraps, so he could call it a forge and build the same shape because he still has the three or four rings of the 'pallet' wrap steel, though the aluminium Rivets were melted on some, and call it his new 2013 Forge when he can feel well enough to decide what to make it with, but with fire bricks stacked loosely around it the fire would not have to be on for more than a couple of minutes then he would be able to carry maybe a previously made little hand pallet of 4 bricks to warm his exceptionally efficient new tent, built as I have said above with the same fireproof cloth used for the overalls in foundry's. Even with no fire it may well be too warm. he actually left a slight gap underneath the edges of the tent to allow air in so he never woke up dead kinda thing you know? The pellet source you describe is not something he would like, his idea was to camp as he always does in areas known as Widow Makers, which for obvious reasons is a place where the tree branches knock against each other and break off so they can be heard falling and breaking at the hit the ground on some of his videos, so the place is 'chocker' of dead wood so that any camp fire can be supplied with fuel for weeks without hardly ever getting out of his rope made chair come bed! He lives I thing in Louisiana, though don't quote me on that, and there is hardly any places near him or within walking or hiking distance that is not flooded pretty much all year, so one of the very successful things he has made is a method of lighting a 'small' fire, with emphasis on the small, enough to cook a meal and then let die down or a drink and it folds down to just a centimetre thick. That is really his forte designing very clever bits that make things easier for those who must camp and either by choice or not have to do it in boggy areas, he has made many brilliant things all based around a cooking stove or grill which is definitely not meant to keep warm by just for a 20 minute breakfast. He is very experienced in this as a metal machine shop worker with his own shop he is also a very good welder. Take care bb

Whoever set the fire needs his brains changing, fat too much fuel (therefore too much heat!). Almost no control over the air drawn in and no control over the exhaust gases, you always need a throttle in the chimney to work in conjunction with the input air control.

That fire is working almost like a blast furnace because of the missing controls.

The longer/higher the chimney, the stronger the "chimney effect" will be....

If I was designing a fire for a tent (or anywhere for that matter) , it would be a closed off stove type with full air control, the size would be small (commonly called a "Barge stove" in the UK), and the chimney would be double walled (as I believe Tornado has already mentioned).

Those small boat stoves will have input air and exhaust gas control already built in....

A UK Barge stove of reasonable quality would be an easy way to go, only a double walled chimney pipe needs to be added.

These stoves are probably heavier than you wish, but far, far safer!!!!

I looked for some informative web sites and found these, where double walled chimneys are also available:-

http://www.stovesonline.co.uk/boat-barge-stove.html

http://www.youtube.com/watch?v=bzQvDa896Bc

http://www.youtube.com/watch?v=7oIJpD2dPX4

http://www.youtube.com/watch?v=5f8CtkH-qEs

You will need to search in a similar way for similar products where you live, or building your own from a gas container as in the videos would be cheaper, lighter and a lot of fun.......

Hi Andy, Many thanks and how are you? The chimney if he makes another that is, would be no problem for these design artist. Everything up until now has worked wonderfully and I think he may still be burning over this fire debacle. I don't like to say it because even if a distant one he is a friend, but I had mentioned of an air control in the chimney. I am not too sure how successful that would have been with what seems to have been a carbon fibre chimney that once lid seemed to draw air in through its walls. I think even he as the meekest person and not one to sing his praises and I do not refer to this recent incident! I have never seen a Barge Stove, but can understand they must be pretty small, it sounds like it is the way to go if as I say he still wants to continue with this fire and tent mixture? The thing is the fire was fine on the one occasion where he had it come down to just above the grilling plate and he had a separate cover made from the fireproof silver material he used on the tent to stop and little embers from exploding into and on to his sleeping bag. It was only when he roughly pinned an extra piece of the carbon fibre around the bottom done to keep the wood and food in and it was just a loose piece as I say clipped onto the chimney above, and it seemed to be this that made the fire draw like mad and unlike the first time where it was alight most of the night the covered version went crazy. I am going to check out these barge stoves though I am not sure if they have them in the States, and again not sure if he wants to do anything similar, with some other choice methods like hot rocks taken from an outside fire I am pretty sure he has used, and I know a lot of these outdoors types often use the rocks to kook on. Personally I think I would feel safer with a couple of fire bricks that can be guaranteed not to explode, I know they weight almost nothing but would need a separate bag for them and on a trek that is not always easy. I will check out the stoves thanks Andy. Are you able or is anyone able to encapsulate the reasons in a scientifically understandable way for this chimney not working? It is all very well with many saying it is obvious but he freely admits he is no thermo nuclear expert, so any explanation of the whys with perhaps air flow and item sizes would be a great help if nothing else of help when he finally does come out of his depressive cave to try again, though I know he has already said he wants to concentrate on tiny tweaks to his already feasible and works well 'fire place off the ground' designs made with strong steel but also meant to fold down to nothing, several people must have copied him as they were so great plus there was no need to bend down and get wet when an easy fire could be made using I believe it was an old or an el-cheapo frying pan as the grate. Take care, and many thanks bb

If you want to control the combustion rate you have to control the amount of fuel, the amount of oxygen, or the temperature. U.S. hunting camps use steel enclosed cook stoves in high wall canvas tents for cooking and heating. Stoves are airtight and have dampers to control air, metal chimneys with dampers, and are manually fed to control heat generation. No combustible materials within a foot or two of hot metal surfaces. Have a good size CO2 extinguisher nearby. Use water in an emergency but expect to damage/warp/crack the stove.The American plains Indians had open fires in their tepees but controlled the fuel feed and depended on a design that maintained a natural draft to remove any smoke. Their tents were made of buffalo skin which didn't ignite easily.

Hi Greycay, You grabbed my attention with the details of the American Hunting Stoves, I will look into that more, thank you. The fact is though I think my friend may have put any ideas of a 'portable' fire-place for use inside the tent though we will have to see. So far his ingenuity apart from this one thing has known no bounds, exceptional space saving but also strong and stable cooker grill designs. He makes most of his stuff where thin rod in concerned with welding rod and once welded it has great weight bearing. He also was pretty much forced to find a way of cooking, which for the most part was in a pan on a grill, because most places he goes has pockets of water surrounded with wet sod or what we would call here in the UK 'Peat', so any fire at just about anywhere easy to get too mostly had to be above ground. The cooking stove he made and the cooking shelf and fire hearth you can see as he builds this fire up you will note is off the ground, he used a successful design cooker and just wrapped the carbon fibre around it. From what I have heard even if he had enough of the silver fireproof material he covered the frame with, and he designed as a one man tent because he had so little of this silver stuff, with a low roof, just high enough so he could sit in there, as I say even if the chimney was made from the silver material, which I do not know the name off, it would have not been much safer because although it and the inside cover could take the heat, it would have made for even more of a roaring fire if as some have said the inverted funnel design makes a more efficient blast furnace than a small tent flue. Take care. bb

Thankfully native Americans never heard of fire resistant vinyl, or chimneys.

If they had we probably wouldn't have had as many of them to deal with as we did.

This is a stove I have had in my TV room for over 30 years. It is a convector and the external surfaces never get hot. It is rated for direct contact with combustible surfaces.

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Hi welderman, I love your stove, looks absolutely classic and uses known designs to the best. Unfortunately it is not very portable, even if beauty outweighs that fact. Take care and many thanks. bb

Sounds like your friend essentially designed a modified "Rocket stove" (Do a Google search - you'll get lots of info). The way it works uses minimal amounts of fuel, but draws significant draft to get very hot with very complete combustion. A double-walled, insulated chimney is essential for the tent application.

There are now very compact camping stoves based on this approach (Biolite stove and Solo stove come to mind), as well as people using the stove design along with mass heat storage for domicile heating (look up rocket stove mass heater).

And a suggestion for your posts - please split up your single large paragraph into smaller chunks. One large blob of text can be really hard to follow.

Hi Peter, Many thanks for contacting me and giving what sounds like some interesting info on camping stoves. I think my friend designed a chimney which fitted the size of frill area and then shrunk it down to what he thought was a reasonable size to use as an exit for the chimney. There was no attempt to build anything as I understand it more than to link the space between the fire and the roof. As it turns out he probably would have been better using the same dia chimney rather than the inverted funnel which quite by accident, was what he needed to fit his needs.. I have not looked yet but I am hoping your details about rocket stoves might be clear enough to try and get him to view and understand where he went wrong. He has had just over a 1000 You Tube members write to him with all sorts of theories, but nothing hard and substantial kinda on paper if you see what I mean. The design was an accident in more ways than one, so I volunteered to ask my friends on CR4 about what exactly went wrong and why with something less than half the fuel he would use on a normal camp fire this one went completely haywire. Take care, bb

Hi Peter, I actually did split it all up, but I have a MAC which cant handle the sites code. I should have used google Chrome, but it must be all of three years since I was on the forum and just never thought of it sorry. I will try to remember after this though. I found your links pretty interesting, thanks. Take care bb

Hi to all,

My friend was in touch today with an update.

It was Oak or Ash.

I do not know enough about fire lighting (which is why I am asking on byehalf of my friend) to know if this matters or not. I suspect it does not matter, as long as the wood is dry?

Take care . . . I hope thing is a little easier to read as I have a MAC this site does not deal with Safari I presume it is I was sending previous stuff by, so I am now using Google Chrome.

bb