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brack
02-12-2004, 12:46
hello there. i have a pepsi can stove that i have used for a while. i use it with a lightweight windscreen and some tent stakes for a pot stand. my stove design is the same as on the pcthiker webpage. pretty much just your standard pepsi stove. but i just noticed the pepsi stove on the antigravity gear site needs no potstand because he has moved the burner holes to the sides of the can. has anyone had experience making this stove or using it? i didnt know if i could make that stove simply by moving the holes when i make a new stove. thanks for your time...

StoveStomper
02-12-2004, 13:10
I'm not to crazy about this design.
It will require a heat up time of a minute or two to get the jets going before you can put the pot on top.
Wasted fuel and it will be very tippy.
Tippy and boiling water do not mix well. :-)

kevin
02-12-2004, 20:06
I've made a couple of stoves similar to the design on the antigravity gear and they seem to work reasonably well. Mine are probably not as well made as the ones for sell there, but they do the job of boiling water pretty well. Maybe a 20-second startup time before setting the pot on them. I can see the concern about stability, but if you get a relatively flat surface to set it on I don't think it will be a major problem. I carry some alum. foil to set the stove on and spill a small amount of alcohol under/next to the stove to light it.

Rain Man
02-12-2004, 23:33
... but i just noticed the pepsi stove on the antigravity gear site needs no potstand because he has moved the burner holes to the sides of the can. has anyone had experience making this stove or using it?...

I have that stove and think it's great. No problems with tipovers for me ... yet, although I know of one that tipped over when put on an unstable picnic table, instead of on the very solid and stable cooking shelf nearby. No names given to protect the guilty. :)

Rain Man

.

Lilred
02-13-2004, 08:15
I have that stove and think it's great. No problems with tipovers for me ... yet, although I know of one that tipped over when put on an unstable picnic table, instead of on the very solid and stable cooking shelf nearby. No names given to protect the guilty. :)

Rain Man

.


HMMMM....... :-? If I recall correctly, there was someone walking on the picnic table, which caused the spillage.........

No names to protect the guilty..... :p

Grampie
02-13-2004, 09:57
I use a different version on the Pepsi can stove. I can :p put the pot right on top of the stove. After a couple of tip overs I made another using a Fosters beer can. Just a little more weight, but it's much more stable.

LBJ
02-13-2004, 13:00
I just received my Antigravitygear stove and think the design is great! It is well made and the holes on the side are a big improvement over the pepsi stoves I have made. Just be careful when you set your stove up and you won't have tipovers.

Rain Man
02-13-2004, 13:31
HMMMM....... :-? If I recall correctly, there was someone walking on the picnic table, which caused the spillage.........

No names to protect the guilty..... :p

I bet it was right there to be stepped on, as there was no other way out of the shelter? But there was another place to cook??? LOL

:jump

Nameless

.

Peep
02-13-2004, 15:00
I tried to make the Anti-Gravity stove myself from the pic on the web-site. I can't get the lighted fuel to come out the jets before I set the pot on it. the flame goes completely out. One thing I didn't duplicate - I didn't curve the top of the can in. In other words, the sides of the can are straigght. I placed the holes about halfway down the can. ???? What did I do wrong?
Keep in mind I practically don't know what I'm doing - ever. :D

chowhound
02-13-2004, 18:42
I also made a copy of the Anti-Gravity stove, and am very happy with it. It may be just luck, but it appears to be somewhat more efficient (less fuel per boil) than my other homemade pepsi can stoves. The first time I tried it though it went out. I found that I needed to punch four equally spaced holes around the top in the same position normal holes would be located. They light the side holes and after the pot is placed on the stove I suspect that they act as breathers pulling air or hot gasses in. Anyway, after punched those holes it worked great.

kevin
02-14-2004, 02:32
I tried to make the Anti-Gravity stove myself from the pic on the web-site. I can't get the lighted fuel to come out the jets before I set the pot on it. the flame goes completely out. One thing I didn't duplicate - I didn't curve the top of the can in. In other words, the sides of the can are straigght. I placed the holes about halfway down the can. ???? What did I do wrong?
Keep in mind I practically don't know what I'm doing - ever. :D

Peep,

Here is what I did...not really a duplicate, but seems to work reasonably well and has the side holes. Note -- my craftsman skills are pretty close to non-existant so these are pretty basic.


First, cut off two bottoms so that each is about 1" high.
Then in one of the bottoms, cut four slits (up to the part where the can bottom starts to form.
On the inside of the can without the slits, spread some JB weld.
Slide can with slits into can with JB weld and press together. Be careful when the cans are almost all the way together as the points where the slits are can cause the outside wall to split. Allow to dry for a day.
Then put in about 4-5 small holes on the top (to pour in the alcohol) and about 14-15 holes around the can (I use a small drill bit to make the holes). Seal bottom with flue tape.
To light, spill a small amount (less than 1/2 a cap) of alcohol around the stove and light. Let heat up until the flame is coming out the sides and place on the pot.


Using both the JB Weld and the flue tape is probably redundant, but I figure it can't hurt. I think I might have to give Bob's Foster can a try as it would definitely help the stability.

Peep
02-14-2004, 17:27
Thanks chowhound for the help with my homemade Anti-Gravity alcohol stove. I have it working after putting 4 holes around the top of the can. I had about a 60 sec wait for fire to come out of jets, but with holding the pot over (not on) the can while fuel is firing, I wasted little fuel. Once I placed the pot directly onto the stove, I had 2 cups of water boiling in just under 3 minutes. This was with using 1 oz. of fuel. After the boil point, the fuel still was firing thru the jets, so I still had cooking time left. If I used 1/2 oz. fuel, I had just enough fuel to heat the 2 cups up to boiling point before fire went out. This stove rocks.
Kevin, I think I'll try making the stove you mentioned and see how that one does.
Thanks again you guys.
Peep

Tinker
02-14-2004, 18:04
I made one last winter when there was nothing to do. As a matter of fact, I made one out of cat food cans as well. The stove is a slow cooker, as air does not get into it as fast as a Roy Robinson cat stove (the fastest boiling one I have made to date), and you have to wait for it to warm up before you put your pot on top or you will extinguish the flame. You do, however obviously save the weight of the pot support. If you use tent pegs, you are ahead of the game, but what if your tent is set up? In my internet search I came across an article on pot support height. Optimum height regardless of stove design seems to be between 2 and 3 inches. I use 2-1/2 because it fits into my Evernew ti pot.

As I mentioned, I spent many hours on design and experimenting on stoves last year, and one thing I did decide is that a stove that burns longer after it brings your water to a boil is better than one that brings your water to a boil fast but then goes out. There are a myriad of designs on the internet. If you have the time, try them all.
Have fun.

Tinker

Stuart Johnson
02-24-2004, 15:15
I've use a similar Pepsi stove and have had no problems with getting it started or with tipping, etc. Of course my cooking pot is pretty small and I only boil water. Most of my mixing and eating is done out of zip-lock bags. Also, not using pot stand means one less thing to fool with.

aardvarkdave
02-25-2004, 04:11
I'm new here so be gentle! I've been playing around with the pepsi stoves for a little while in preparation for a PCT thru hike, and have found a way of making them that is definitely much easier, and I think is new?

I wanted to get away from flue tape and JB weld (neither of which I had to hand when making my first stoves!) to simplify the design for 'trail construction'.

Basically, you cut the bottom off one can to form the burner unit. You then take the other can (ideally still full of pepsi to give it structural integrity) and push the base of it into the cutoff can. Although the two cans are the same size, the rounded base enables you to force the full one into the cutoff one, and stretches the cutoff one slightly. You may need to do this a few times, and wobble the full pepsi can around a bit whilst its pressed in just to stretch the edge of the cutoff bit slightly more.

Now make the rest of the stove as before, except don't bother with cutting slits, or JB weld, or flue tape. Also, you don't need any JB weld around the inner wall- if you cut it straight and use two slits to lock it together, or better still make it from a complete cut out cylinder from a smaller (v8/grape juice) can.

Then slide the two cans together, with your slightly stretched burner unit very carefully sliding over the fuel reservoir and forming a tight seal. I've made 4 of these - no flame leaks, 10g lighter, and all boil a pint of cold tapwater on 2/3 of a fluid oz of alcohol.

2XL
02-25-2004, 07:16
Does your stove look like one on this page?:
http://www.backpacking.net/makegear.html
If not, could you post a pic.
Edited to say: I was aiming the link for the pop can stove but got the home page instead.

aardvarkdave
02-25-2004, 07:54
There's a lot of stoves on that page! Assuming you're talking about the convex stove then I'm using a vaguely similar principle, but my stove looks just like any other pepsi stove except for no slits in the side to fit the burner over the reservoir, no JB weld, no flue tape.

I am however using the principle that you can fit two halves of a can together snugly, but as mentioned, I do it by 'stretching' the burner unit first so that it fits onto the reservoir without neeeding to have slits cut.

I'll try and post some pics after the weekend, but they probably won't show much!

Edited to say - been back to look in more detail at all the stoves on there, nothing identical, everyone on there uses slits or ruffling to get the two halves to go together. Mine was based on scott's stove on pcthiker.com

2XL
02-25-2004, 08:51
Oh, now I understand. I thought you were talking about a new design.
I have made several the pct hiker stoves, and used the same pattern to copy the anti gravity stove.
Putting the two cans together is the most frustating part of making a stove. I will try your technique.

Just interested;
What size drills or pins are people using for their burner holes? I use a # 60 drill bit.

aardvarkdave
02-25-2004, 09:40
I've tried different sized pushpins for the holes, and use the relatively large pushpins with a cylindrical plastic body, as opposed to the little pushpins that you use for kids pictures on a wall. Interestingly I get little difference on my various stoves with different pinhole sizes.

My favourite is sgt rock's ion stove, but made using my 'stretching' technique. Very reliable 16ml boiler, although i haven't managed to get it down to 12ml like he has (albeit he uses slightly warmer water).

To think I always used to lug a pound of whisperlite around!

Rain Man
02-25-2004, 12:33
Basically, you cut the bottom off one can to form the burner unit. You then take the other can (ideally still full of pepsi to give it structural integrity) and push the base of it into the cutoff can. ...

Now make the rest of the stove as before, except don't bother with cutting slits, or JB weld, or flue tape. Also, you don't need any JB weld around the inner wall- if you cut it straight and use two slits to lock it together, or better still make it from a complete cut out cylinder from a smaller (v8/grape juice) can.

Dave, I thought I was right with you up until the point where you started talking about cutting slits to lock it together and using a V8 can. Where the heck did I get lost?

I've built several plain pepsi can stoves, cut off a bottom, cut off a top, and press them together.

Rain Man

.

jlb2012
02-25-2004, 12:48
Rain Man - I think Dave was talking about the inner wall that is typically made from a strip of side wall of a can whose ends are slotted together.

aardvarkdave
02-25-2004, 13:01
ended up doing it because I had so many offcuts from grape juice cans after making ion stoves and then reaslied they were the perfect size for the inner wall.

I've done about 30 burns so far with no issues, but has anybody found any long term problems with not using JB Weld/flue tape? I wouldn't want to find the 'press together' design fails after a 2 weeks in the field!

jlb2012
02-25-2004, 14:23
I've made a fair number of stoves just pressed together using a different technique and I only use the aluminum tape if I see a leak from the sides during the first test burn. The technique I use does occasionally result in leaks - I put small crimps in the upper edge of the bottom part of the stove before fitting the bottom part into the top part of the stove. Depending on luck (I think) sometimes one of the crimps pushes the side out enough to cause a leak near the crimp. Anyways once I have a good one with no leaks I have never seen it begin to leak with use so I would say that there are no long term worries about your technique. Its a good idea - one possible improvement would be to use a can mostly filled with frozen water for the forming tool - it would be better than a full but liquid can IMO.

Lilred
02-25-2004, 18:05
ended up doing it because I had so many offcuts from grape juice cans after making ion stoves and then reaslied they were the perfect size for the inner wall.

I've done about 30 burns so far with no issues, but has anybody found any long term problems with not using JB Weld/flue tape? I wouldn't want to find the 'press together' design fails after a 2 weeks in the field!

I've never used any JB weld on my cans, no slits cut. I do use a little bit of masking tape to hold the inner wall together while I'm fitting the two cans together. But I pull that off when they're together. I do use the heat tape on the outside though.

I like the earlier idea of stretching the can with a full one. I'll have to try that.

Sand Crab
02-26-2004, 01:04
Can someone explain the purpose of the inner wall? I built my stove just by pushing two cut off bottoms together with nothing in the center (also no cuts, crimps, weld or tape). It seems to work just fine and was easy to make, except maybe for the aggravation of fitting them together. Is the inner wall supposed to have any effect on efficiency?

aardvarkdave
03-01-2004, 09:27
Can someone explain the purpose of the inner wall? I built my stove just by pushing two cut off bottoms together with nothing in the center (also no cuts, crimps, weld or tape). It seems to work just fine and was easy to make, except maybe for the aggravation of fitting them together. Is the inner wall supposed to have any effect on efficiency?

My understanding was that it helped increase the focus the heat and evaporation on the alcohol by the jets, increasing pressure a little thus causing the alcohol vapour to come out of the jets slightly faster, and mixing more with air before burning. The turbulent flow of air through the jets (ie pin holes) is important for mixing with enough air to ensure complete combustion. In the absence of an inner wall I'd expect much more flame leakage and less efficient burning.

Saying that, I haven't actually tried making one without the inner wall- I'll give it a go and see if there's an efficiency effect. Always worth questioning the key assumptions! Could be another 15% weight reduction on the way!

aardvarkdave
03-03-2004, 07:43
I found this great site for all the various design tweaks - might provide some inspiration. Unfortunately, like many people, he's most concerned with boil time. I'm far more interested in fuel efficiency (ie weight of fuel used).

He suggests that the inner wall helps efficiency a lot.

http://www.datasync.com/~wksmith/hojo.html