Hi, Chisel,

I'm not completely sure what you mean by "methanol is too 'light'". Methanol works pretty well as a fuel. It's pretty popular. Methanol doesn't have quite the heat content of ethanol, and methanol is more toxic, but it works pretty well as a fuel.

As far as blending fuels, I've not tried nor do I know anyone who has tried blending methanol and isopropanol. I would think you'd have a blend that would a) smoke less and b) have a higher heat content per gram than pure methanol. Sounds like a worthwhile experiment. If you try it let us know how it works.

HJ

What I meant is this (quote from your blog)



Methanol burns "too easily, too quickly" , so mixing it with something that burns "not so well" may give us a fuel that is just right (similar to ethanol).

I would have tested the theory myself but in my neck of the woods ALL stoves around here are gas stoves. Esbit and alcohol stoves are never used by local campers. So, alcohol (methanol, denatured alcohol ..etc.) is non existant as a fuel in the camper market. I really don't know where to find them. Even gasoline additives ( HEET) does not exist here, and we have different brands which I may investigate.

Now, I know, you will ask ( if you can't get alcohol , why are you asking about it and how do you plan to use it ??)

OK. first, I am a prepper , not a routine type of camper. So, my stove needs may differ from the public. Second, around my work I found small quantities of methanol , iso propanol, denatured alcohol ..etc. And I plan to make a homemade alcohol stove and keep it for emergency use only if I had to bug-in the office due to bad weather or other problems, and power was out.. At the same time , I cannot use these in non-survival situation because the bilding is a no-smoking zone.

In the market , we have barbeque lighter fluid ..etc. but they are smoky and sooty , so they are definitely not methanol or denatured alcohol, maybe isopropanol or such.

Something else HJ

I am fascinated, no , I am OBSESSED with letting no atom of substance, or photon of energy, escape unused. What I mean is to have maximum efficiency possible. So, the caldera and few other designs ( like the Swiss Ranger stove) offer what I absolutely love in a stove which is a built-in windscreen to comletely surround the pot (almost hide it from view) and guide the heat to engulf the pot from all sides, not just the bottom. Even the escaping hot emissions, keep touching the pot to the last moment.

This is the same reason that I absolutely loved the rocket stove made of mud in some 3rd world countries ( seen in u-tubes) .

So, HJ, do you know more of such designs that minimizes escaping heat and focusing & condensing the heat around the pot ???

Oh, I get it. Sorry, I didn't catch on with the terms "light" and "heavy".

I'm not sure that methanol burns "too quickly" or that isopropanol burns "not so well". It's a bit more complicated than that. In this situation, it has more to do with vapor pressures at a given temperature. BEFORE EVERYONE'S EYES GLAZE OVER, I won't bore you with the detail, but suffice it to say that in hot weather, methanol can boil so vigorously that you lose efficiency ("excessive" thermal feedback). In cooler weather, methanol is great.

Isopropanol actually puts out plenty of heat and doesn't have any trouble staying lit or anything like that. It's just that isopropanol doesn't burn cleanly.

The idea of mixing the two for hot weather (to avoid excessive thermal feedback in the methanol) has some merit, but I don't know how it would work. The isopropanol has a very high heat content and might just exacerbate the excessive thermal feedback. I haven't tried it.

Some people will mix just plain old water with their methanol to retard excessive thermal feedback. I'd say water is the way to go until we get some experiments done.

HJ

If you really want efficiency, check out a Trangia 25 series or Trangia 27 series stove. They're pricey, but they are going to extract every last erg out of the alcohol.

A (much) cheaper version is the knockoff Ledmark set. They're available at campmor.com for $20.00: Ledmark Alcohol Cookset.

The Caldera Cone is a cottage industry product and is a little pricey. For bugging in, the weight isn't going to be as big of an issue, and the Ledmark set will do you.

As far as fuel, check out a paint or hardware store. If there's a marine store near you, check out fuel for stoves on boats. Denatured alcohol is pretty available across the US. Methylated spirits are often available elsewhere. Methyl hydrate is sold in Canada and will work in alcohol stoves (I believe it's methanol).

Charcoal lighter fluid is typically petroleum based. I wouldn't use it in an alcohol stove.

HJ

Note: I have no affiliation with any product or site mentioned in this post (other than my blog I mean).

Reminds me of Sterno which is roughly 30% water and 70% ethanol.
Sterno's flame is not very hot but who knows, if you use it within a very effieicent system like caldera or Ledmark, maybe we have the most feasible combo.

The ledMark design gives me an idea. Maybe all I have to do is use a can instead of the cone . I can visit a store and choose a can of something ( Nido powdered milk for example) and a pot that can go inside ( held in place by the lip of the rim). Remove the bottom of the can. Drill holes near the bottom for air inlet, and holes near the top for emmission exit. Volia, A "caldera cylinder" LOL.

To operate, ignite a Sterno can , put the "Caldera cylinder" around it , and insert the pot inside top of the can.

It will all depend on finding the right fitting pot and can. And the can should not be too tall. Maybe the medium sized Nido can will do, but have to find a fitting pot.

What do you think ??
Sounds simple and doable, unless I am missing something.

A can instead of a cone might work, but I doubt it would be as efficient. Stoves like the Ledmark etc. are pretty well tuned to get the airflow right. You want cool, oxygen rich air entering from the bottom, flowing up past the burner and then up the sides of the pot in a controlled fashion that doesn't allow any outside gusts to rob you of heat.

The burner itself needs to be of a proper design so as to get the air/fuel mix right. Sterno cans are hardly the ideal stove. They're pretty lean on the air. Sterno is designed for long slow heat and really isn't all that good for cooking, more for keeping something warm.

When the Ledmark is only $20.00 I guess I'd probably just go for the Ledmark which comes pretty well recommended by the guys I've talked to who have one. Of course if you're into DIY, you could try a can stove and see if it works well.

HJ

I have fashioned a "semi-Caldera cone" using aluminum flashing and tent stakes. Compared to a can, the rig can be rolled up compactly with a canteen and pot. In testing, it has worked very well. The cost was trivial (under $4). The only drawback is the method of fastening - nuts and bolts. Very secure, but fiddly.

Ok Jim. You pushed me over the edge. I was already considering a Ti-Tri for my MSR Titan Kettle. Gonna have to get one ordered asap.

At the end of my Caldera Cone blog post, I added a video of someone making a "Caldera clone." This is just a video I saw on the internet that I thought might be of interest. I bring this up because he made opposing folds in the ends of his cone that, when slipped together, held the windscreen in a conical shape.

HJ