Rubbing alcohol instead if denatured?

[lissersmith]

How does this compare? Is it as fuel efficient? It is certainly more readily available.

[Rasty]

At 70% alcohol it won't produce nearly as many Btu's as 90%+ Heet type denatured alcohol

[MDSection12]

At 70% alcohol it won't produce nearly as many Btu's as 90%+ Heet type denatured alcohol
I've heard it burns dirty too, very sooty.

[Theosus]

I've seen it in action in a Cat Food Can stove (your mileage may vary in other types of alcohol burners).

Denatured Alcohol: Very clean burning. Almost invisible pure blue flame in daylight. Pour in, light, and wait the requisite twenty seconds or so. Put pot on stove, and very soon blue flames are coming out the sides. Denatured is about 195 proof (97% alcohol) according to my hydrometer...

Rubbing Alcohol: Burns dirty, leaving soot behind. Visible yellow flames. Pour in, light, wait for twenty seconds or so. Put pot on stove. Stove burns very low or goes out. Flames never come out the sides. Hold pot over stove in yellow flame... try again, stove doesn't burn. Rubbing alcohol is 140 proof (70%).

I have tried 160 Proof (80%) alcohol in my stove. It doesn't burn well either once you put the pot on. It comes out the sides for brief periods, but always retreats back into the holes. Pure grain alcohol (Everclear or another off brand) would work in a pinch but be very expensive.
If you have an open-center-hole soda can style stove, it may work better with lower proof alcohols, since they seem to be able to tolerate lower temperature fuels. Cat Food Stoves need the higher temperatures to vaporize the fuel inside the can and force it out the side holes.

[Blue Mountain Edward]

91% isopropal alcohol will burn in a alcohol stove. It will smell terrible and leave soot on the pot. It is almost as smokey as the experimental cotton ball dipped in petroleum jelly stove I saw a hiker using once.

[FarmerChef]

91% isopropal alcohol will burn in a alcohol stove. It will smell terrible and leave soot on the pot. It is almost as smokey as the experimental cotton ball dipped in petroleum jelly stove I saw a hiker using once.

Yes. I tried it at first and it left a brown varnish on everything. Smoky and lower heat. Worked enough to test the stove but I quickly changed to denatured. Cheaper too.

[Another Kevin]

Speaking as an engineer:

It is possible to design a stove to burn the 91% isopropanol cleanly, but it's a very different design, and much harder to build, than the simple soda can stoves we all use. It neads a generator tube to preheat and vaporize the fuel (because of the lower vapor pressure) and a venturi to premix the fuel vapor and air. It starts to resemble a Whisperlite, except that it has to be made of different materials because the 9% water in the mix is so corrosive. If you're going to go that route, it's cheaper and more efficient to burn gasoline - in which case, just buy a Whisplerlite!

The 70% isopropanol would be even more of a challenge. I can't think of any design off the top of my head that would burn that stuff cleanly. You simply lose too much heat because you heat the 30% water in the process of boiling off the alcohol vapor.

Methanol (HEET in the yellow bottle) burns well. Ethanol (Everclear) burns well. A mixture of the two (denatured alcohol - the other denaturants don't affect the burn very much) burns well. Isopropanol (91% is HEET in the red bottle, or you can sometimes find rubbing alcohol at that strength) burns quite badly, and dilute (70%) isopropanol and the higher alcohols (fusel oil) are even worse.

Some of these fuels will burn reliably in an open dish burner, or in a lamp with a wick, but that's an inefficient way of burning them. Compare trying to boil water in a chafing dish with boiling it on a stovetop. It's like that.

Every hardware store has denatured alcohol, every gas station in a trail town has HEET, even out of season, and a lot of mom-n-pop stores in the trail towns have one or the other.

[zelph]

Speaking as an engineer:

It is possible to design a stove to burn the 91% isopropanol cleanly, but it's a very different design, and much harder to build, than the simple soda can stoves we all use.
.

I had success with this design to burn Iso, denatured and olive oil. simple and efficient. I no longer make them, piece of history.:)


http://www.youtube.com/watch?v=sYUORYSl6Gg


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

[JAK]

How does this compare? Is it as fuel efficient? It is certainly more readily available.
One of my favourite topics, trying to get difficult fuels to work.

Damp Wood = 0-400 BTU/oz ( dirty, unreliable, value depends on how damp it is, but readily available )
Dry Wood = 500 BTU/oz ( example is dry sticks snapped off of spruce tries, reliable and readily available but only in some places)
Charcoal = 500-800 BTU/oz ( in theory could be made from wood, and carried to next campsite to start the next fire)
Beeswax = 1100 BTU/oz ( very slow, sooty when trying to heat something with it, but great for candle light and safer than vegetable oil )
Vegetable Oil = 1000 BTU/oz (burns very sooty, very slow, requires wick, very dangerous if spilled hot, but a good lamp fuel and doubles as food )
99% Isopropyl = 800 BTU/oz (burns sooty, and slow, but has potential given it heat value )
95% Ethanol = 690 BTU/oz (burns really well and is safest, and most useful for first aid, but not as cheap or readily available as 100% Methanol )
100% Methanol = 525 BTU/oz (burns best, most readily available, but lowest heating value by weight)

Combinations that work well...
1. Use whatever dry wood fuel is available as your primary fuel for cooking
2. Make charcoal or save some charred wood to carry for next camp in case things are damp
3. Soak charcoal or charred wood with in a little beeswax or vegetable oil, for a very efficient small cook fire
4. Use beeswax candles as fire starters and as candles and simmering stoves, and for waterproofing laces, boots, zippers
5. Use Vegetable oil and Jute Twine as a backup lamp and simmering stove when beeswax candles run out
6. Carry some high quality 95% alcohol primarily for first aid, but also for quick easy boiled water, like when stuck in out of rain or wet snow.

Depending on the rest of your kit, and if you can managing getting a little dirty, combinations can be fun to mess around with. Haven't found a lot of good uses for the 99% Isopropyl Alcohol, considering that 95% Ethanol burns better and is better for first aid, and stuff like vegetable oil is almost as clean and has a higher fuel content and is also food. Still might make sense to carry it as a hand and pot cleaner and sanitizer and use the used wipes as fire starters. Just an idea. Then the question is what to bring for wipes. Toilet paper or perhaps industrial brown paper towel might hold up better and be more environmentally friendly. Dried leaves in fall maybe. Or the jute twine which is also useful for lashing stuff, and wicks, and for scrubbing. Scrub with it first, soaked in alcohol, then burn it as your fire starter. Just some ideas to mess around with.