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Woods Walker
06-03-2007, 08:06 PM
Alcohol stove with windscreen.

I have built a good number of alcohol stoves. After testing them out here is what I settled on for my favorite. The standard Pepsi can stove with Aluminum flashing windscreen. I use tent stakes for a pot support. Here is the link with instructions on how to build the burner.

http://www.pcthiker.com/pages/gear/pepsistove.shtml

The whole system packs down small and weights in at under 2.5oz complete.

http://i113.photobucket.com/albums/n220/Daytraderwon/100_8133.jpg

Calling it a Pepsi can stove is not being 100% fair to the Irish beer can that is used for the bottom. It appears that the Irish beer can is just a very tiny bit smaller than the soda can. This allows me the slide the cans together and connect them without any expansion slits in the Pepsi can top section. I put a bead of hi temp epoxy around the lip of the Irish beer can before slipping both cans together. Than for good measure I place a bead of the same Hi temp JB weld over the newly created lip. No real reason for doing this. The inner wall ring is connected with JB weld. Unlike the Pepsi can instructions I use material from a 24 oz Arizona Ice Tea can to construct the inner wall ring. This is done as the aluminum stock from these cans are thicker than the Pepsi can or Irish beer can. Stronger inner ring makes for a stronger stove. But you can use stock cut from the Pepsi too. I also put JB weld underneath the top grove that the inner wall fits into. The combo of all these things keeps air from being sucked into the inner wall turning the clean blue alcohol combustion into a more reddish flame.

http://i113.photobucket.com/albums/n220/Daytraderwon/100_8134.jpg

The fuel intake is controlled by 3 holes or notches in the bottom of the inner wall created with a hole punch. Guessing that two would be enough but have settled on 3. I have tried various hole sizes and numbers for the burner and have came to the conclusion that 24-28 small holes burn the cleanest and most efficient. Do I have hard-core scientific data to back this up? No but than again it is only a stove.

http://i113.photobucket.com/albums/n220/Daytraderwon/100_8141.jpg

The windscreen and pot support is one of the most important aspects of any alcohol stove. Darn important factor in most other camp stoves too. One thing I donít like about side burning stoves is that people tend to use the stove as a pot support. A soda can is a tinny pot support any way you cut it. Other times they try to add wire to the stove or push 3 tent pegs into the ground for a pot support. Better but these methods are not ideal in my view. Why not just combine the two? Have the tent pegs be supported by the windscreen and than use the windscreen to support everything. Air intake is provided by either holes drilled into the aluminum flashing or groves cut into the bottom. I have shortened the high of the windscreen from my earlier design. Reduced it from 6 inches to between 3-4 depending on factors like cook pot size and my general mood at the time. A shorter windscreen is a bit less efficient but this offers a few important advantages. First and foremost the cook pot handle gets a bit less hot. Second being smaller pack size. Not going to add reduced weight, as we would be taking about grams and that is just silly. A grove is cut into the top of the windscreen so cook pot handles will not get hung up on the lip. The tent peg support holes are drilled to support the pot about ĺ of an inch above the burner. Donít know the optimal height for this but thinking anything less than 1.5 inches is good to go.

http://i113.photobucket.com/albums/n220/Daytraderwon/100_8144.jpg

The width of the pot support depends on your cook pot. I made this one to work with all my small pots and metal cups including the MSR, Snowpeak and USGI canteen cup. Here is the stove complete with a USGI canteen cup.

http://i113.photobucket.com/albums/n220/Daytraderwon/100_8149.jpg

This may not be the perfect Alcohol stove set up. But it has worked best for me. I use this all the time with my daypack for cooking and boiling up some coffee. If done right it can get a rolling boil with most small cookpots/canteen cups in under 6 minutes. One big pro of the top ported stoves over the side port models is the easy addition of a simmer ring. I will update this thread with photos of that after it is reworked. These stoves can be made for very little money and like most projects the feeling of accomplishment and fun from building something your self is well worth the time and effort.

Jim N
06-03-2007, 08:41 PM
Nice presentation WW. Thanks!

Len
06-03-2007, 08:43 PM
Thanks ww. I have been interested in these stoves but have yet to build one. Looks like a fun project to do with my son.
Thanks again for the great photos.

evanhill
06-04-2007, 09:37 AM
I've also learned that windscreen and pot support height are key with alcohol stoves. When I built my stove, I spent a long time in the kitchen figuring out exactly what the correct pot height is for optimal burn. My burner unit sits inside of a tuna can which forms the windscreen, and the pot supports are angled pieces of tin that just slip onto the perimeter of the tuna can. In colder weather, I'll splash some alcohol into the bottom of the tuna can as well as into the burner unit. This secondary burn superheats the actual burner unit very quickly to get things cranking. When I break it down, everything including pot supports all slip into the tuna can and a lid goes on it. Very compact, and keeps the fragile burner protected in my pack.

It has been a handful of years since I benchmarked my burn time, but I think it was ~6 min for 2 cups of water.

http://www.evanhill.org/images/stove.jpg

Rusty Hook
06-04-2007, 11:00 AM
When I bought my Trangia Stove, it came with a big heavy pot support in the package. The support was too bulky and heavy to use for backpacking and I would have never bought it if I had had a choice, but it provided me with a good measurement (3/4" just as WW has specified) for building the different pot stands that I tried and used with that and other stoves that I have made.

The 3/4 inch space isn't universal among all alcohol stoves. It varies with stove type, burner type (side burners usually set the distance by their burner port location on that type of stove because the stove is used as the pot support), and other factors but is really accurate for the top burner ported Pepsi can type stoves in my experience.

I also liked the idea of not having to carry around a separate pot support in the beginning to save weight, but I also found, as Woods Walker has so abley said, that the stoves alone made too unstable of pot supports for my uses and the pot also had a tendency to rob the stove of too much alcohol generating heat under cold conditions, reducing its efficiency to some extent as well.

For cold conditions and burning these stoves on cold surfaces, and also for height adjustment using a too high of a pot support of any kind, you can cut off the top of a Pepsi can and invert it to make an insulating stove stand to raise the stove up off of cold surfaces. The air space provided insulates the stove and is really light weight. It friction-fits onto the base of the stove quite nicely by just pushing it onto the stove. The removed pop-top gives you a place to push on the base of your stove with a finger to get the stove and the insulating base apart. I also find a little higher stove position to be easier for me to work with in lighting the stove with a butane lighter, and the base helps the stove burn more efficiently in cool to cold temps or any time at all.

I really like WW's wind screen and pot support all in one unit set up. Especially as you could have different tent stake location holes for different stoves and different pot height requirements. Using one windscreen and pot support system for all or your stoves. Great idea, write-up and pictures Woods Walker. Thanks for the tips; they are much appreciated by everyone interested in these stoves I am sure. Thanks again...Rusty.

Sea Cadet
06-04-2007, 04:15 PM
I have created a couple of alcohol stoves in WYSOG with Mr. Cutter's guidance(anthracitic) and they came out really well! We just used a couple of pop cans and it came out looking pretty nice!! Any aluminum can will work in this. This needs to be an unopened can. Put a cut in the middle of the can and squeeze the pop out. We cut the can into thirds and get rid of the middle. We then put a hole the size of a quarter in the bottom. Use a hole puncher to make 12-15 hole in the top 1 centimeter from top. We put the bottom of the pop can inside of the top so it has 2 layers. It should look O.K. when it is all done.


http://i96.photobucket.com/albums/l165/rcutter/MinivChimney.jpg



http://zenstoves.net/ChimneyStove.htm

Woods Walker
06-04-2007, 05:04 PM
Sea cadet

Looks like anthracitic picked a fine stove design. Not surprising. I have a Chimney type Alcohol stove. It is not homemade. But still works on the same principals as your stove.

http://i113.photobucket.com/albums/n220/Daytraderwon/brassstove.jpg

A very efficient stove. One thing to consider is that Chimney Alcohol stoves are a bit more susceptible to wind. I think the reason is the lower pressure of the flame. Don't know if you made a windscreen for your stove. If not copy mine.

evanhill.

First I would just like to say nice avatar. Secondly I like your burner. I built one just like it. I settled on the open port stove as it self primes. But think the higher-pressure stove like yours burns a bit hotter. Like your wind screen/pot support too.

Rusty Hook

In winter I carry a bit of fiberglass insulation to keep the stove off the snow. My Westwind pot support keeps the Trangia burner off the ground so you are very right about the airspace below a burner for snow etc.

evanhill
06-05-2007, 09:07 AM
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> First I would just like to say nice avatar. Secondly I like your burner.</div></div>

Thanks, and thanks!

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> In winter I carry a bit of fiberglass insulation to keep the stove off the snow. My Westwind pot support keeps the Trangia burner off the ground so you are very right about the airspace below a burner for snow etc.</div></div>

... so fiberglass is the trick? I'll have to try that. I'm here to tell you that a piece of closed cell foam with duct tape on it is *not* a good choice.

Rusty Hook
06-05-2007, 09:33 AM
Things like the foam, fiberglass insulation, a small piece of plywood and such will all work well in the snow to keep your stove from sinking down into the snow from its heat melting the snow. However, these burnable and melt susceptible surfaces need to be protected from the stove's heat with a foil heat reflector and or the raised stove insulating base that I described above. None of these things take up much room or weigh a lot, and they are useful in spring, summer and fall as well as winter...Rusty.

Sea Cadet
06-05-2007, 10:11 AM
Woods Walker,
I like the idea you have for the wind screen. I'll try the fiberglass too.

Woods Walker
06-05-2007, 03:35 PM
Rusty

The fiberglass insulation tends not to burn.

Sea Cadet.

If the burner is placed in snow etc it will just not want to prime. Also use Denatured alcohol for fuel. Don't use Rubbing alcohol as it does not put off enough BTUs. In the day light the flame from an alcohol stove can't be seen so care must be taken. Don't refuel the stove until you are 100% certain it is out and you can pick up the burner. I once burned my eyebrows when my nearly empty fuel bottle took off like a rocket during refueling.