I'm new to the forums and see that I'm not the only one who's wanted to "lighten up" the classic Kelly Kettle.

The Classic

(through-link to Kelly Kettle image)

For background see these pages:

http://www.backpackinglight.com/cgi-bin/backpackinglight/reviews/display_reviews?forum_thread_id=1011&cat=Stoves%20%2D%20Other&cid=21

http://www.backpackinglight.com/cgi-bin/backpackinglight/xdpy/forum_thread/3262/index.html?skip_to_post=32209#32209

I'm working on a prototype of a leaner, meaner double-walled aluminum kettle, and I'm trying to gauge what kind of interest there is for this kind of cooking system. Here are the anticipated specs:
- under 5 oz total wt
- 14.5 oz water capacity
- approx 9" tall operating
- collapses to 7.25" x 3"
- welded aluminum construction
- carrying bag/ handling sleeve included in wt
-reusable mylar bags can be used to mix meals/ drinks (no need for additional pot)
- *a bit more delicate than the original, but what ultralight gear isn't? (still far more robust than a Foster's can!)
- $ Price = Depends on welding cost - I'll update

Right now I have the prototype all cut out of sample components and I'm trying to find someone in the area to do the welding for a good price. Other than the samples I'm working with, there is a minumum order of about 150 for each of the components I'm using, so there would need to be a good deal of interest if I were to make more than one.

Here are my questions:
1. How much interest is there in this kind of stove?
2. How much would people pay for it? (broad range, I know it will depend on finish quality)
3. Are these the kinds of specs people are looking for? Larger means heavier, and worse, bulkier.

I'll provide pictures when it's all done.

Thanks!

Edited by dsmontgomery on 03/27/2010 07:29:20 MDT.

Sounds good. I’d pay about $50-?? for one if it had the right specs.

Suggestions:

*Capacity should be 16oz--most meals require this amount
*Inner wall could be very thin--better heat transfer and less weight.
*Increase heat transfer by increasing inside surface area--add 10-20 vertical “fins” (1/4" to 1/2" wide)welded to inside chimney surface. These would run the full height of kettle. Will increase costs but greatly improve efficiency
*Add outer insulator (like jet boil)--thin neoprene or equivalent.
Steve

Edited by Steve on 04/24/2007 23:08:30 MDT.

Devin,

I'd be interested in hearing/seeing more. You might consider posting the same message at the G-Spot section in these forums; I think more people will see it over there. Good luck with your project. Looking forward to updates. Mike

Thanks for the suggestions, Steve. I think you're absolutely right about about the capacity and the inner wall. I'm trying to find a container that's a bit larger with the same wall thickness for the next version.

Your idea of fins is ingenious - it would function like a radiator, only it would efficiently collect heat rather than efficiently dispersing it. My concerns with installing those would be price and the fact that fuel might get stuck on them as you feed this kettle from the top.

I'm also looking for an inuslating material for the outside that would be light and durable enough. Do you know what light weight neoprene weighs per sq. ft? I've been thinking about making a carring bag out of a 4.5 oz/yd PBI/Kevlar material (like nomex, only lighter). You could then fold it up to make a sleeve and stuff in some socks, etc. into the sleeve and use the whole container for a winter thermos.

Anyway, my almost full sized version is at the shop to be welded and I hope to get it back early next week.

In the mean time, check out the "test of concept" model I made a couple weeks ago out of seltzer, mini coke, and Red Bull cans, the top from and aluminum Budlight bottle and some JB Weld.

Not the final version!


It weighs 1.2 oz, holds 4 oz, and I got it to boil in under 1:30 on less than .5 oz of carboard box while taking these pictures. Sure it's a bit small, the fire box won't last through 10 burns, and the water comes out tasting a bit like high temp. epoxy solvents, but it sure was fun, and really got me excited about this kind of boiler.

Edited by dsmontgomery on 04/28/2007 12:06:18 MDT.

Thanks, Mike. I think I'll definitely get it up in the G-spot once my prototype is finished and I've been able to run it through some tests. There sure seems to be more traffic there.

Edited by dsmontgomery on 04/28/2007 11:59:41 MDT.

3mm neoprene can be purchased here:

http://www.questoutfitters.com/neoprene.htm

Not very heavy – a 4"x4" square is 10grams.

You could eliminate the fire pan to save some weight. A piece of foil under the kettle with the kettle tilted up by a small rock will work almost as well. One could also make a "donut trough" to hold alcohol for times when dry twigs are not available. This would keep the flame(s) burning near the inside wall of the kettle to maximize heat transfer. Good luck Devin--no one to my knowledge has yet built a light weight and efficient KK. You could be the first!

Edited by Steve on 04/28/2007 15:35:29 MDT.

Sgt Rock mentioned working with some CF Plumbers Cloth that is flame resistant and fairly insulative. Might be an option rather than the neoprene...

Steve - thanks for the source and the ideas for the stove. Many thanks for the words of encouragement. You're vicious when it comes to saving weight, but I'll give the "rock 'n foil" thing a shot when I get the kettle back from the shop - if that ever happens. For my next version, I'll just make the whole thing out of Ti foil and finish it off by rigging up an aerogel cozy!

I had the same idea about an alcohol burner, or esbit chunk for woodless days, and your trough would distribute the flame rather than send it straight up the chimney.

Josh- I think that plumber's cloth is pretty close to the PBI/Kevlar mix I was considering. Once I have the kettle to mess with, I'll try to figure out if I'm going to go with a fabric like these, a foam, reflectix, or a combination. I'll be going for light and multi-use where possible.

As things are right now, it looks like I won't get it back until sometime next week. The shop I took it to only has one guy that's good with Aluminum this thin and he's pretty well booked. Better that than having a newbie on it, I guess.

Argh - bad news. I got a message from the shop where I left the kettle saying that it was to thin to weld. That's pretty frustration considering the fact that I dropped it off three weeks ago when they said it wouldn't be a problem.

One possibility is that it is too thin, and that the guy I left it with didn't know what he was talking about, and the other is that they're too busy with other, larger, jobs to mess with a difficult, small, job like this one. The latter is a real possibility, as they were most frequently out of the shop with on-site jobs when I would call to check up on the status of my piece.

At this point, I think I'm going to pick the kettle up from the shop and temporarily set it up with *sigh* Jb Weld. Even though I won't have something that I can use to boil consumable water, at least I'll be able to determine the performance of the other parts of the system, just not the sealing method.

So, it's a setback, but not an insurmountable one. I'll post pictures and data from my tests of the kettle once it's mocked up. I'll also do some searching for the minimum weldable thickness of aluminum, and other sealing methods. I know that the Kelly Kettle company rolls their seams and spin forms their components, but that opens up a whole new can of worms and much larger minimum production numbers.

Edited by dsmontgomery on 05/14/2007 08:21:25 MDT.

That is a bit of bad news, but like you said it's a setback, not the end of the line. I think you are really on to a winner if the kettle works well and is light cause many ultralight backpackers only need to boil water to make hot drinks and rehydrate food--but do not need to cook. The Bushbuddy has the advantage of giving people the option to boil or cook, but like I said, many don't need to cook, and the kettle means that the backpacker doesn't need a pan/pot. Having said that, I see from the Kelly Kettle that an add-on grill and cook pot are options--and may be possible with your design too. I think it's worth pursuing your idea. Hang in there! --Mike

How thin is it? I've welded down to 35 thou aluminum before and a bit thinner than that shouldn't be an issue.

Edited by Pivvay on 05/14/2007 16:41:42 MDT.

Thanks for the support, Mike!

Chris - I don't know exactly how thick the vessel itself is. The thickness wasn't listed by the Al bottle wholesaler I got the sample from and I don't have a micrometer. My guess is that it is .02 or thinner. On a side issue - I read in an old post that you were working on something like this - any luck?

Anyway, I got it back from the shop and I could see that they had tried to weld it, but were unsuccessful, and I'm frankly glad they stopped before it ruined the whole container. As soon as I got it back, I set it up with JB Weld, waited the obligatory 24 hrs and fired it up. See the photos and key below:



Photo 1 - the kettle as originally planned, collapsed into pack mode with a plastic stopper in place so it can hold reserve or cooking water while carried.

Photo 2 - original design cooking. The firebox really wasn't large enough and it took about 10 minutes of fiddling to get a good boil. Check out the kindling - cut up carboard. It's not very good compared to small dry sticks, but I couldn't find any in our miniature yard.

Photo 3 - a surprisingly quick fix - I assembled and cut up a cylinder from some .019 Al sheet and a few blind rivets.

Photo 4 - the new setup weighed with a larger gain than I wanted. After firing, I determined I could cut this down by .5" - .75" and get the weight to about 4.5 oz - leaving it .5 oz under my goal to allow for a cozy/carrying bag yet to be made. The holes in the cap that make it look like a pig's snout minimize heat loss and maximize the amount of water that will stay in the kettle (rather than boiling out).

Photo 5: Still packs up small and fits my original size goals. In addition to the vessel holding water while packed, I imagine the carring sack holding it all together and covering the top hole so that dry starter kindling, starter tabs, matches, flint, etc. can be stored in the chimney.

Photo 6: A much, much better boil this time around. It took just under 6 min, but I ran out of pre-cut cardbord half way through, and I'm sure I could do far better with a better fuel. Some water did go out the snout, and I had a net boiled water volume of 14oz.

All in all, I still get a kick from the thing. After half a dozen boils, I may taste test the water. JB Weld is supposed to be non-toxic and I imagine the water should act as an effective enough heat sink to keep the JB in contact with it below the critical 500 deg continuous operating temp, but I still don't entirely trust it.

If the water it produces ends up tasting okay, I'll bring it with me on my next trip, but I definitely won't be ordering 140 of those bottles. I'm now conviced that it would take a complete revamp to move this from a one off "make your own" to something with greater appeal. I'm going to look into that this summer, but in the meantime, I'll add posts on the fate of this one.

Edited by dsmontgomery on 05/16/2007 22:17:10 MDT.

I love the whole Kelly-style boiler model...any news on this project? I use a Trangia and a model that would take both Trangia and wood would be wonderful!

Thanks for the interest John! It’s actually kind of absurd how obsessed with making a workable version of this kettle I’ve become. I have made some real progress, but it’s been slow given the amount of time I have to commit to the project. Here’s more than you ever wanted to know:

I gave up on trying to make it out of available components, and decided I would have to start from scratch - bare aluminum sheet. So I downloaded Google’s Sketchup (awesome program for novice 3-d design), and designed a vessel and fire base that would weigh about 5 oz together, pack to 3 3/4" by 6 1/2", and boil and carry approximately 20 oz of water. Then I made a working mock-up of my design with aluminum sheet, some blind rivets, and JB-weld. The mock-up came in at about 5.8 oz (added weight was from rivets and epoxy), and could boil 20 oz of water in just under 6 minutes from lighting a match (awesome!). I did a number of tests (my notes are around here somewhere), and I think it took just about 2 oz of sticks for a good boil. They burned down to absolutely nothing, save a few white wisps of ash. I was really impressed with its weight and performance, and that my calculations and design had been pretty good.

So I sent copies of my design files and technical specs to a number of metal spinning and hydroforming shops for quotes to build a legit prototype. I knew this would be a big expense, but again, I was obsessed, and I figured I could probably sell enough of these to at least recoup some of the overhead for temporary mandrels (forms). Unfortunately, I found that the places that worked with the cheaper tooling (only $800 for the set I needed :) ) weren’t able to get the final material thickness I wanted, and the kettle would end up being 2-3x as heavy as designed. I did find some higher-end places that could get the thickness right, but only worked in permanent tooling that would run me about $6-7K. This was obviously more than I could spend, even if I could recoup some of it by selling a few.

I then decided to see if I could just make it myself, so I got some books on metal spinning and bought a low-end wood turning lathe, and some other shop tools. I got the necessary materials to convert the lathe to metal-spinning and to make my own spinning tools, and did so relatively easily despite my complete lack of experience. Then I got some maple and made the mandrels for the 3 pieces need to make the kettle and the aluminum sheet to form around them. I originally thought the mandrels had come out pretty good, but either because of the flimsy, cheap lathe, or the fact that I made them out of solid, unseasoned maple (instead of several laminated sections as was suggested), they ended up a bit warped. Despite their imperfection, I tried to spin the fire base because it was the smallest piece. Unfortunately, in addition to being flimsy, the available speeds on the lathe were too high and its power was too low to properly spin the metal without stalling the motor or stretching the metal to the point that it would tear.

I now have a better lathe with more power and the proper speeds. Unfortunately, my “workshop” is on the balcony of our 1 BR apartment, so all efforts have ceased for the winter. Once things warm up again, I’ll make some new mandrels and give this another shot.

Here's a close-up of the mock-up:



Here are a few of my spinning attempts, getting progressively better until the end where I tried to use even thinner sheet. As you can see, each has torn at the shoulder as a result of being overworked at high rpms:



Oh - and to answer your actual question about a Trangia - I haven't tried it with one of those, but it should work with burners that are small enough to fit in the base and have a flame pattern wide enough so the heat has good contact with the walls before heading up and out of the chimney.

Edited by dsmontgomery on 03/12/2010 09:13:59 MST.

Lofty goal! Do you use heat besides that of the tooling while working or during rest periods to allow the stresses to dissapate? Copper should go easier? Although heavier, but 2x the heat transfer of aluminum could be worth it.

Edited by Paul_Tree on 12/16/2008 16:26:13 MST.

Make that twice the heat transfer and 3.5 times the weight.

I've considered a copper chimney for a kelly kettle, but I can get most of the heat out of the flue gases by the time they exit so I don't thnk it's worth the weight penalty. If you cool the exhaust gases too much they stall and choke the stove.

Yah, made it 2x.
3.5 times the weight - ow.
At least it would be protected in there.
Interesting about the low-temp stall.

>Lofty goal!

No joke! Thanks for putting it so kindly, Paul. :)

A philosophy major, my only knowledge of metallurgy comes from what I've read researching for this project, and my sources tell me that aluminum generally doesn't need to be annealed while spinning. Almost all spinning is done cold, but it is recommended that copper be annealed periodically while working on a piece to do exactly what you suggest - reduce hardening from the cold-working.

For my purposes - focusing on both light weight and minimized pack volume over absolute efficiency, I chose a compact, aluminum design for the project. Once I have it all worked out in Al (no small task, right?), I'd sure like to make one in Copper for its good looks.

Edited by dsmontgomery on 12/16/2008 16:56:20 MST.

Maybe home anodizing? It might not get messed up too bad by the heat. Or it might, and look really cool.
Like a logo, it could be a stencil that sticks on and stays throughout the process. Made out of a sticker, or tape.


You could blacken inside the cone for the alcohol stovers.

Right on! I looked into hard anodizing for at least the inside of the kettle in order to make it easier to clean and to prevent aluminum from leaching into the water. It would be a great way to put a logo on the outside, and more importantly, a warning not to heat it when the stopper is in place (steam bomb). I called a local place, and it would only cost $5-10 per piece if I did a number of kettles at the same time. The only problem might again be that the metal is so thin that the high voltages they use for the hard anodizing might burn through, so I'd have to test it on one first.

For the black chimney - fortunately, after just a burn or two, the soot from the wood makes it nice and black!

> I got the necessary materials to convert the lathe to metal-spinning and to make my own spinning
> tools, and did so relatively easily despite my complete lack of experience.

Blimey! Just like that. Nothing like fanaticism!
I do a little metal spinning myself, but on a smaller scale. It is not easy! I am greatly impressed.

Aluminium: ask at the suppliers about what alloy they would recommend. There are some alloys which will be a right pain, but there are other Al alloys which are meant for bending and spinning. They 'flow' more easily.

Cheers

>Blimey! Just like that.

:)

Yes, well that was certainly the longest and most difficult part of the project. I gave it the gloss so I didn't entirely bore everyone with the details, but "relatively easily" was, well, relative. Mostly it meant that I was actually able to do it and that I hadn't had any catastrophic failures in the process. I know that some people go crazy making spinning tools by hot forging them and everything, but I got the how-to on making the right kind of tool rest, combination spinning and planishing tool, and cutting tool from a video I rented from Smartflix.com (Netflicks for nerds, and an awesome resource). I shaped the tools themselves with a grinder and then sanded and polished the combination tool. You should have seen the looks my neighbors gave me as the sparks went flying!

>I do a little metal spinning myself

Cool, what have you worked on? As I started reading and watching this stuff on metal spinning I got really turned (no pun intended) on to it. It's still amazing to me that someone can form metal (what seems like such an alien, industrial process) on a simple wood lathe at home.

>Aluminium: ask at the suppliers about what alloy they would recommend.

Too right. My supplier has been McMaster-Carr and I've been consulting their metal suitability chart. So far I've been working with 3003 because it has good workability characteristics, is okay for use around food, is corrosion resistant, and is a bit stronger that 1100. At first, I was worried that the walls of the kettle would be weak, which is why I chose the 3003, but given the strength of my mock-up and that it's actually going to be pretty hard to get the metal as thin as I want, that may not be an issue. The 1100 is supposed to have even better working and anodizing (should I go that route later down the line) characteristics, so I may make the switch.

Thanks!

Hi Devin

I am NOT an expert on spinning, not at all! My efforts have been mainly with titanium in small sections. Some titanium alloys will form, while other will NOT. 6Al4V (usually in sheet form) will NOT, while 3Al2.5V and CP2 (often used in tubing) will.

I have been using a ball race as the spinning tool. A lot of force is needed with titanium.

As to what Al alloys: best consult a supplier. I got some sheet from a local sheet metal fab shop: they knew what the different alloys would do.

Cheers

Hi Devin,

Thanks for posting your MYOG metal spinning project I am finding it all very interesting, I have wanted to spin some pots for a while now.

I recently cut off a JetBoil PCS pot (anodized aluminum)and rolled a lip on it using my metal lathe and a ball bearing tool clamped in the tool holder it was not as successful as I had hoped.

I think will now try some real metal spinning.

Thanks for sharing.

Tony

I had an idea how to make such a kettle out of "recycled matrials" - aluminium gas canisters (the largest ones, like the one on the picture).



One canister, with the bottom removed, would be uused as the outer shell. Upper part of second one will make bottom of the kettle. The chimney would have to be made from something different, possibly some aluminum bottle.

With the edges overlapping as in the picture, it might be possible to weld them without making holes in the shell (hopefully, I have not much experience with welding).

Roger - I think it's going to be quite some time before I have the cojones to try titanium, but that's very cool, even with small parts.

Hi Tony - It's very encouraging to have garnered the attention of you and Roger, two of the MYO greats! I think I saw your pictures of that pot somewhere around here. With your know-how and equipment, I'm quite sure you could make your own pot to whatever specs you like and then spot-weld on some shim stock for less than the price of a cannibalized jet-boil pot. I don't know how available the proper tools are in your neck of the woods, but I found the pre-made tools to be hard to find and very expensive. Like I wrote earlier, I leaned how to make mine from a video I rented, but if you PM me, I'd be glad to send you pictures of mine along with a diagram and brief instructions that would probably be enough to go on. I think my combination tool and trimmer together cost about $80 to make, but it would have been over $200 to buy them both.

Jan - that looks like just the kind of container I was looking for when I was aiming to make this out of off-the-shelf parts - I could only find aluminum bottles that were skinnier and taller than I really wanted. By all means, you should give that a shot. I'm just so far down the rabbit hole at this point that I can't turn back!

Thanks all!

Hi Jan

VERY smart!
You could try a high temperature epoxy for the joins: the metal should not get much over 100 C because of the water on the inside. Well - it would let you experiment anyhow.

For the bottom - maybe you could use the existing metal bottom?

For the core: maybe some Al tubing? It might not need to be really sealed at the top at first?

Cheers

I had this idea in my head. Hope this drawing makes sense.


I am by no stretch of the imagination a metal fabricator and have no real tools. I was thinking that you could use some aluminum or Ti bowls. The kettle would be more squat like a traditional tea kettle. This is a crude sketch. I guess it may need handles as well.

Edited by magillagorilla on 12/19/2008 12:43:14 MST.

Hi Daniel

Dunno, but I suspect not enough chimney height.

Cheers

I've almost finished new mandrels for the kettle. Over the holidays, I cut up some wood billets at my father-in-law's, and laminated them together for new mandrels that shouldn't warp. I also got my wife's permission to temporarily "close in" our balcony to stay warm. I've finished rough turning them, and I'm going to work on getting all the tolerances right after lunch (I'm on winter break from grad school). I've also adapted my metal spinning tool rest for the new lathe, so if all goes as planned, I should be able to start spinning the kettle tomorrow! (knock on wood)

Edited by dsmontgomery on 03/12/2010 09:15:05 MST.

Update: Well, I guess I didn't knock hard enough...

I was able to spin the fire cup (the smallest part) the next day, and got a pretty good piece on my first try.




The outer wall and chimney were a different story. Without getting into it too much, the fact that they're longer and that their faces (the part that clamps the metal circle against the follower block) are narrower asks a lot more of the lathe setup. In this case, it was just too much for the wood-turning live center, and when I would apply pressure, both the mandrel and follower block would deflect making it impossible to shape the metal.

The only fix was a more rigid lathe and a true metal spinning live center. Luckily, I was able to find a Karle Spinmaster lathe, complete with live center, online (they don't make hobbyist size metal spinning lathes anymore, so this one was rare and an antique). It should be on its way to me as we speak, so once I get it all set up, I'll be able to make another attempt at those larger parts. What time I would have saved myself by starting with the right tools!

Edited by dsmontgomery on 02/04/2009 09:26:58 MST.

There are some products out there that allow brazing very thin AL. I haven't tried them personally but I would expect you could simply roll your chimney and outer shell and braze the seam to form a cylinder. Then braze that to the top and bottom sections that you spin.

With tight tolerances and narrow overlaps added weight would be negligible. Overlaps at the joints would stiffen the assembly significantly allowing you to use thinner metal for the sides for some more weight savings.

I bought an alloy brazing kit off ebay. More properly, it's a solder, brazing refers to temperatures beyond the melting point of aluminium, but it solders at around 450C so plenty good enough for a kelly kettle.

I tried soldering beer can material, but it's tricky to keep the heat even and avoid blowing holes in the material. I'm looking at setting up a rotating table and a pedal operated flame direction changer so my hands are free to manipulate the solder rod and flux.

I'm sure the makers of the original Kelly Kettle have tried too, and they still make them at the thickness and weight they do because of the difficulties.

Hat's off to Devin for his efforts.

Sorry for shouting, but after 2 years, four lathes, and more money than I care to think about, I've successfully made an ultralight storm kettle! Here are the specs:

weight: 6.0 oz
dimensions: appox. 4" wide by 7.5" tall when collapsed
boiling capacity: 20 oz
projected time to boil 20 oz (based mock-up trials): 6 min

Picture:

Collapsed, sitting on the lathe:


* you may notice some tooling marks, the bottom bead is wider than it should be, and the spout hole is a bit screwy, but the thing will hold water, and proves that I can actually make it. My technique needs some work, but at least I have the right tools, and the basics down. I'll update when I'm able to test fire it, and make a more refined prototype.

Oh, and thanks Rog!

Edited by dsmontgomery on 02/10/2011 09:10:42 MST.

Devin, well done! Looks very good indeed, and 6oz is a tremendous achievement.

How did you do the jointing between the chimney and outer skin in the end? Just rolled and pressed? Or soldered?

Thanks!

Yep, it's just rolled over - I have some water sitting in it right now, and there don't seem to be any leaks. I'll see how things go when I have a chance to boil with it.

Very well done!

This is one heck of an achievement!

A measure of the difficulties involved may be appreciated by the fact that the Kelly Kettles, Eydon Storm Kettles and Ghillie Kettles are all manufactured by the one metal spinning company which has decades of experience, and a fully equipped engineering workshop/manufacturing facility!

Hi Devon,

Some great work, well done, I look forward to seeing some more work.

Tony

PS: I know what it is like to be addicted to stove making, I have also spent more money that I would like to care about.

BLIMEY!!!!

Have you thought about writing it up?

Cheers

I had a quick look at those commercial versions, the closest is the Small Kelly Kettle , 570ml so possibly 1 fl oz less , and that is 17oz, almost 3 times heavier !
I used a much bigger and heavier NZ made version (car camping) and I liked the relatively contained fire, it worked in the wind (and rain !!!) and no pot to clean up , it was also very fast and not that fussed about what kind of wood was used in it .
For the ones that only boil water it seems to me a better alternative to the BushBuddy and co (?)
BTW, Devin, try if you can , a tea light type alcohol stove in it , could be a dual fuel solution...
When do we place orders for this one ? (time to get some money back)
Franco

Thanks guys! It's much more gratifying to share this here than to simply shout in excitement from my balcony. It also seems less crazy. :)

Callahan
>Kelly Kettles, Eydon Storm Kettles and Ghillie Kettles are all manufactured by the one metal spinning company

That's surprising, and sure raises the question of why there are three companies all selling the same kettle made at the same place...

Tony
>I know what it is like to be addicted to stove making, I have also spent more money that I would like to care about.

It is like some kind of rabbit hole, that one just falls farther and farther down. I tried to go into this with both eyes open, made a budget for materials and equipment... but there always seems to be another tool that is needed, or the original one doesn't work quite right. Or something breaks. I just about doubled what I planned on spending.

Roger - I'd love to write it up at some point! Right now my mind is just racing with ways to refine my manufacturing process...

Franco - you've hit on a lot of the reasons that I became so excited about this project. The key advantages to the internal chimney are speed and protection, but existing kettles were too large and heavy to fit into an ultralight load. For about the same boiled volume, not only does mine weigh so much less, but it also takes up a less than half of the pack space (approx 95 ci compared to approx 250 ci). Given the weight and volume of my design combined with the inherit advantages of an internal chimney, wood burning boiler - and I think it's great!

Alcohol adaptation - certainly on the to-do list. Placing orders - I would love to disseminate my creation, and look forward to getting it to a stage where I can do that. Again, that's going to take some refinement in the finishing of the boiler and a smoother mfg process, but BPLers will be the first to know!

Edited by dsmontgomery on 06/26/2009 07:55:10 MDT.

Amazing, simply amazing ...

I spite of my strong MYOG interests I've made just one simple working alcy stove followed by a couple flat out failures.

I hold you stove makers in awe.

Hello,

Having first read a post on an outdoor forum last year, that the three Kettles were made by the same company, and wanting to be absolutely certain of my facts, I emailed the company which makes all three for confirmation.

I received confirmation within minutes, from the man whom has been spinning Kettles for the last 25+ years!

Prior to making this post, I checked the original email confirmation, which is dated 24/11/2008.

That manufacture should be contracted to one specialized engineering company should not be too surprising, given the nature and complexity of the Kettles (from the perspective of diverse, volume production).

And the name of the company is......... (o:

>That manufacture should be contracted to one specialized engineering company should not be too surprising, given the nature and complexity of the Kettles.

That's true - most of the metal spinning places in the US that I contacted would only make the constituent parts, but wouldn't do the final assembly.

Well done mate!

It's good to see someone persevering and succeeding with an idea. Brilliant!

WOW, what a journey! That thing looks beautiful! Simply fantastic work my friend. I for one would love to see a MYOG article on this.
I'm not sure how much information you want to share on this (seeing as you may end up selling it) but I'm interested in what the original and final spun material thickness ended up being? What size of sheet did you start with to make the shapes? Any chance you took step by step pictures...or are you guys saving them for the article?

Again, awesome work.

I've been playing with making a modified Kelly kettle out of beer cans.

I wondered about adding a heat exchanger to the chimney to encourage heat transfer, and ended up using the side wall of a one pint beer can, folded with vanes.

The folding is a pain in the butt, and requires some better means of securing than JB Weld (I'm unhappy with the use of epoxy for foodstuffs...).

There are plenty of opportunities for improvements, but the basic idea seems to work. I need to find a more compatible burner than the chimney-style that I've got here; it's a bit too fierce on fuel, and unburnt fuel comes out of the top (and can be re-lit!).

The finished kettle & burner weighs 40g, with another 15g for the cosy. It only holds about 250ml, though (it's a 440ml can). Good for a brew or water for a dehydrated meal.

> Sorry for shouting, but after 2 years, four lathes, and more money than I care to think about

LOL! Looks great, though. Fantastic dedication.

I stick to beer cans, craft knife, Bic pen and glue; it's a lot cheaper... ;-)

> I wondered about adding a heat exchanger to the chimney to encourage heat transfer, and ended up using the side wall of a one pint beer can, folded with vanes.

Kevin, I found what worked best was to form the vanes into the chimney itself. This has the advantage of increasing the surface area in contact with the water.

Very nicely done Devin.

Question: is the final product durable enough to be stored inside a backpack, or is the metal thin enough to require that you nest it inside a pot to protect it (e.g. like the Bush Buddy?)

Spinform seems to be the manufacturer for those UK kettles..
BTW, those three brands are not the same product being of different weight and different capacities.
The one we used in NZ was the Thermette, very similar to the one Devin has made. Ours was provably from the early 70',like this one but green (I think...)
http://www.thermette.com/index.htm
Franco

Those thermette jobs are copper too, right Franco?

Dave
The one I used was provably stainless steel, could have been aluminium ( it was 30 years ago...)
They do have a copper version. (1/2 a gallon , 3 lbs)
Franco

Thanks Steven! - I guess you can relate to MYO projects that take on a life of their own. :) Maybe it wouldn't be prudent to give all my secrets away, especially given the Bush Buddy/ Bush Cooker debacle. Then again it is kind of obnoxious to act like it's some big secret... While I haven't used a micrometer on it yet, I suspect the final wall thickness on the kettle is between .020" and .030," a bit thicker on the fire bowl. I actually don't have any step by step pictures - I was too busy cursing or holding my breath - but I can surely take some later.

Rog and Kevin - very nice alcohol kettles! I knew Rog had been messing around with them a lot, and it looks like you two are headed in similar directions. Little did Foster's know how useful their packaging would be!

Dave - You ask a very good question on wall strength- as I said, the wall thickness varies a little bit right now - some of this is due to the process and some is due to my relative inexperience. Right now, a strong thumb press will leave a superficial dent in some parts of the the outer wall. I'm trying out different techniques and different alloys to find a good balance of strength and other characteristics. As it is, I would feel entirely comfortable putting this in the top of my pack with my food, where I normally put my cooking gear, without any hard protection. I expect that with the normal kind of care one gives to ultralight equipment, it would develop some superficial denting over time, but nothing that would impair its function.

Edit - I should note that I was referring to a stove called the Bush Cooker being sold abroad, not the new one by Four Dog Stove - that one looks pretty cool.

Edited by dsmontgomery on 06/27/2009 08:43:49 MDT.

Great work Devin! Remember...free kettles to the first five hikers in this thread that encouraged you. :)

Steve

>Remember... free kettles to the first five hikers in this thread that encouraged you.

If memory serves, you said you'd pay $50 or more for one... :)

But seriously, thanks a lot for the support! If it weren't for the encouragement I did get from the forum, I easily may not have seen this all the way through. Once I get all the kinks worked out (which may be a while), I'll see if I can hit that $50 you suggested on the first batch. I do have a lathe to pay off, you know!

This weekend I was able to put the boiler through over two dozen burns, to both test its performance and see how it held up.

The boiling times were actually better than I had expected with times between 5:00 and 6:00 for 20 oz and under 4:00 for 16 oz. The differences were accounted for by whether or not I fanned or blew into the intake hole. In other words, it would likely perform better in a light wind as seems to be typical of this kind of boiler.

I also wanted to see how the relatively thin fire cup handled the full heat (as it wasn't cooled by water like the vessel itself). The repeated heating of the cup has obviously softened its temper, but it's still strong and doesn't show any evidence of serious degradation.

Here's a photo - I love the fire plume!

Edited by dsmontgomery on 06/29/2009 19:18:03 MDT.

Congratulations on a great achievement!

Your Kettle looks fantastic, I'll happily buy one.

Cool! I'll make a note!

Please keep me posted, I can relate far tooo much and kudo's for all you've resolved:) I got my Kelly kettle for emergency use/kit for pontooning rivers. Yours makes me want to become far more proficient with dehydrated meals as I'll want to get your modern version of the Irish item.

> married/grad school/ and obsessive

Ha! You have just captured the three central themes of my life in five words. I'm glad I'm not the only one. What are you in for? (grad school, that is)

> Kevin, I found what worked best was to form the vanes into the chimney itself. This has the advantage of increasing the surface area in contact with the water.

LOL! I obviously didn't make myself clear; that's exactly what I did, but my thinking was also that it would be much better heat transfer (simple press fit gives poor thermal contact), and it would ensure that the can wall (and epoxy) never got hotter than 100C.

This is a great example of congruent design; we've both approached the same problem, and come up with an identical solution, even, coincidentally, using the same brand of beer can, although I suspect yours is one of the big 24oz cans, whereas mine is a small 440ml can. There are a couple of other minor differences; I cut a hole in the dimple, which makes the top of the inner stable (but makes filling a little difficult), and I used an odd number of vanes, as this seemed to improve the useful cross-section area of the top opening.

> Maybe it wouldn't be prudent to give all my secrets away, especially given the Bush Buddy/ Bush Cooker debacle.

That was an unpleasant and unnecessary debacle, IMHO. On the thread, I argued the case for congruent design, and lo, Roger and I have given a perfect example of the phenomenon. No doubt bpl's worthies will be along later to shout "RIPOFF!"... I can look back and see how the idea came about, given the past history of things I've experimented with, and I bet Roger can do the same. No doubt the design history is different (and collides a little where Roger's aluminium water bottle kettle gave me a prod to play with some ideas I scribbled on heat exchanger pans when I got a JetBoil), but the end result is remarkably similar. We even made the same error of folding the wall the wrong way so that the paint is the water side, rather than the epoxy-phenolic coating (corrected in the earlier photos)!

OM Bush Buddy Ultra thread
OM How To Make Meths Stoves Q&A thread

Devin, your efforts have caused me to lurch out of lurkdom and post my congratulations and encouragement. Please keep going with this project. Make sure you protect your design and consider seeking partnership from established companies. Who knows? Maybe Mountain House could see enough of a tie-in to assist you in the tooling expenses.

In the mean time, when you are ready to knock out a few yourself I certainly want one!

Thanks JJ! I'm currently working on moving this from a one-off prototype to something that I can make a small production run of. It's taking some time, but I'll add you to the list of folks that I will notify as it gets closer to that point.

Again, thanks! I'm honored to have elicited your first comments!

Devin,

I just stumbled onto this long running thread... Wow! What a great story! What great patience! I'll be watching for developments.

--kerry

Awesome journey- looks like it will roar, right on!

I have been wanting a kelly kettle type stove for some time but have been awaiting an ultralight version. I was cruising the web and here we go!

How do I get on that list to order one?

Cool! Add me to the potential sales list too!

Great work and perseverance!

Doug

Thanks guys! I'll add you three to the list!

Unfortunately, I'm still working on getting that first batch together and am increasingly understanding BPL's reluctance to give stock dates for their custom lines of gear. Since I'm doing 99% of the production myself, I don't have third party delays to worry about, just work, weddings, the call of the trail, and now... school.

I'll keep you all updated on my progress, and believe me that nobody is more eager to get these in your hands than I am!

Patrick - if you set up your PM address, I can either contact you through that or you can send me your email address.

Thanks again!

Hi Devin,
I would love to buy one when you are ready.You have done some amazing work and I am sure they will be worth every penny you charge for them.
Thanks,
Anna

Hi Devin,

I thought I'd bring this up from the ashes to see if you have made any progress with this project. Also, I just ran across this thread on another forum where someone fabricated a kelly kettle out of a 40 oz. stainless Guyot/Nalgene bottle:

http://www.hoodswoods.net/IVB/index.php?showtopic=25081&st=0

Maybe this can add to your inspirition base. Also, Exotac has prototypes ti water bottles pictured on their website. Perhaps whoever is doing their fabrication could produce a ti kelly kettle.

Hey Flix, it looks like you have to be a member of that forum to see the site, but I appreciate your interest!

The project is pretty much on hold until spring. Unfortunately, graduate school and a workshop exposed to the elements aren't the best ingredients for ultralight manufacturing.

Some good news is that since September, I've been able to nail dow the alloy I'm going to use for the kettles! Small progress, I know.

Unfortunately, I think a Ti kettle would be cost prohibitive. With the contortions one has to put the material through, all but the most pliable Al alloys will simply rip apart. Ti exponentially more expensive and harder to work with. :(

Add me to your list, I have read this several time and am continually amazed at the determination and progress

Thanks Malcolm! Please send me a PM with your email address, so I can reach you when this all comes together.

I just got a batch of the new aluminum, and I've got a week of spring break coming up. I sure hope to make some progress!

Awesome. Add me to the list. Love this kind of stuff, and you, sir, are one perseverin' kinda guy.

I learned something important this week: When a commercial spinning shop won't give you a quote in either the alloy OR the thickness you want, making a part that way on your own is going to be really hard!

After making that revelation and moving back to a softer AL alloy (but keeping the thin walls), I have been able to make my elusive second boiler. With that problem solved, I'm ready to start taking the names of those who are interested in getting one of these beauties. But because this is now clearly more than a MYOG exercise, I've started a new thread in the Gear Deals forum to handle their sale. If you're interesting in buying one of these please get back to me there or through PM. If you're interested in metal spinning or making your own boiler of this type, I'm still glad to answer those questions on this thread.

Thanks to all who have followed my work here. Being able to share the process with other ultralight MYOG fanatics has been the most rewarding part of the kettle's development. I can't wait for others to actually get the chance to use one!

Best,
Devin

Edited by dsmontgomery on 03/05/2010 16:00:40 MST.

"I also wanted to see how the relatively thin fire cup handled the full heat (as it wasn't cooled by water like the vessel itself). The repeated heating of the cup has obviously softened its temper, but it's still strong and doesn't show any evidence of serious degradation."

I wonder what will happen if people decide to 'keep the camp fire going' after the boiler is removed. May be worth testing. Perhaps a Ti sierra cup could be modified?

"I wonder what will happen if people decide to 'keep the camp fire going' after the boiler is removed."

That's a good question. I've since run the boiler many many more times (some weekends I just boil, pour, boil, pour, repeat, repeat, repeat), but I haven't yet tested one to failure.

The reason for this: until recently, I only had one. Now that I have a couple to play around with, I be a bit rougher with them. I'll see how it works with extended burn times.

Devin,

What is the top diameter and weight of your burner cup?

The bottom is 2 3/4" and widens to 3 1/2". The lip that the kettle rests on is 3/8" all around, with a diameter of 4 1/4".

Edit: oops, forgot the weight: 1.6 oz. So yeah, the Ti would be lighter. There would just have to be some way to seat the kettle on the cup...

Edited by dsmontgomery on 03/13/2010 18:09:52 MST.

item 350218596862 on fleabay

Ti sierra cup 4.5" dia 1.3oz inc handle. Less once you cut a chunk out. ;-)

Might work well with your kettle.