QuietStove.com

Sunday, June 17, 2012

Happy Fathers Day

Happy Fathers Day from all of us here at Adventures in Stoving

The Adventures in Stoving Team on the trail in Monrovia Canyon
Hope all you fathers out there had some adventures of your own this day.

HJ

Friday, June 15, 2012

California, Stoves, "Campfire" Permits, and ESBIT

I live in California in the United States.  I thought I'd comment about what is and is not permissible with respect to stoves, fires, and fuels in the backcountry here.

Unfortunately, there are a welter of jurisdictions including state parks, national parks, city parks, national forests, county parks, and Bureau of Land Management areas.  Each of these may have their own rules and restrictions.  Even different units of the same overarching agency will have differing rules.

However, there is one thing that is generally required in California across the various jurisdictions:  the California Campfire Permit.  Basically, outside of a developed campground, to have any kind of fire (a wood fire or a camp stove), you have to have a campfire permit.  And, yes, you read that right; you have to have a permit in order to operate a camp stove in the backcountry.  Based on the name, you would think a campfire permit would be for wood fires alone, but, no, a campfire permit is for any type of fire, including all backpacking type stoves.

It's easy to get a permit; just click on the above link, print it, fill it out, and sign it.  You don't have to go to a ranger station, pay a fee, take a test, or anything like that.  I think they just want you to have the regulations in front of you.

A campfire permit generally allows one to use a woodfire, charcoal fire, or "chemical" stove, but each local jurisdiction places additional restrictions as to where fires and what fuels are permitted.    Wood and charcoal fires are generally the most restricted with many jurisdictions confining wood fires to developed campgrounds only.  With respect to those restrictions, gas and pressurized liquid fueled stoves are always OK in state and federally controlled backcountry areas, but I have seen local cities prohibit even gas and pressurized liquid fuel stoves (e.g. the City of Monrovia).  Jellied petroleum (I assume they mean Sterno type stoves) is also permitted (but who the heck uses a Sterno stove?).

Alcohol and hexamine (e.g. ESBIT) stoves are generally lumped in with wood fires and are typically more restricted.  Alcohol and wood stoves are prohibited in many backcountry areas in California, especially in Southern California.  The rule of thumb is:  Where wood fires are permitted, alcohol stoves are permitted; where wood fires are not, alcohol stoves are not.   Unfortunately, the Forest Service lumps ESBIT in with alcohol and wood even though ESBIT is very different (and very safe).  See the Appendix below for further discussion on this topic.

SUMMARY
  • Print and carry a California Campfire Permit
  • Gas and pressurized liquid fuel stoves are almost universally permitted for backcountry use
  • Expect greater restrictions on wood and charcoal fires
  • Alcohol and ESBIT stoves are generally lumped in with wood fires -- and are more heavily restricted
  • Generally, in an area where wood fires are permitted, alcohol and ESBIT stoves are permitted; where they are not, alcohol and ESBIT stoves are not.  
  • Always check with each local jurisdiction as to the specific rules governing your type of stove or fire 
I realize it's a bit complicated, but I hope that helps.

HJ

APPENDIX
So why so many restrictions on alcohol and ESBIT type stoves?  Well, the San Bernardino National Forest website has a helpful Q&A section from which I quote:


Q:  Why are jelly petroleum-fueled stoves okay and campfires aren’t?
A:  Jelly petroleum-fueled stoves can be extinguished by putting a metal lid over the container. This makes their use much safer than campfires. Ashes or hot briquettes can blow outside of the fire pit; these embers can easily start a wildfire. Also, visitors might discard ashes or hot charcoal briquettes before they are completely cool, which could cause vegetation to ignite later after they are gone. Wood, charcoal, or any solid fuel fires are not allowed within the San Bernardino National Forest outside developed campgrounds, picnic areas, yellow post sites, and special use permitted sites in agency-provided fire rings or designated sites at any time of the year.

So, based on the Forest Service's above answer, a fuel that can be reliably extinguished, whose flame cannot be spread by wind, and does not leave behind by-products that might start a fire is an appropriate fuel for backcountry use.  Based on the Forest Service's own answer, I'd say that ESBIT is an appropriate fuel for backcountry use.  Burning ESBIT can be reliably extinguished by blowing it out; ESBIT flames are not spread by wind, and ESBIT leaves behind no by-products that might start a fire.  I think ESBIT gets lumped in with wood fires simply because the land agencies aren't familiar with it.  Bureaucracies being what they are, it probably won't happen, but it sure would be nice if the various agencies that have jurisdiction over backcountry areas would take a second look at ESBIT.

With alcohol stoves, I understand the restrictions a little bit more (note that I said "understand" not "like").  Alcohol can spill and spread flames, and many alcohol stoves cannot be extinguished once lit.

Tuesday, June 5, 2012

Blog Status 5 Jun 2012

Rumors of my demise are greatly exaggerated. :)

 Yes, I still exist even though I haven't been blogging much lately. My new job requires a good deal of commuter travel. Commuting more than 2 hours a day in heavy Southern California urban traffic seems to have sapped my energy to the point where blogging isn't very appealing, even blogging on a fascinating subject like stoves.

Time also is far more dear. With my old job, I had in effect an extra 2.5 hours per day. Those extra 2.5 hours per day are now a thing of the past. Still, I hope to periodically post some updates, and who knows my job situation may change again.  I'm still getting out and dealing with interesting stoves, stoves which I think are worthy of your attention, stoves that I'd like to share with you.

My first priority is of course to keep my family fed, clothed, and housed. My stove blog will never make any real money, and I'll never come anywhere close to being able to earn a living through blogging, so my blog is and will remain just a hobby. My family must of course come first. I do hope you understand and will bear with me.  

In order to whet your appetite, here are a few previews of coming attractions:
The new Primus OmniLite Ti (Right)
Baking on the trail.
Snow melting 101
The Snow Peak white gas stove (a personal favorite)
Wood stoves compared

Stay tuned!

HJ

Friday, April 13, 2012

Gas in Cold Weather: The Myth of "Fractioning"

I'd like to dispel a myth that's out there: the myth of "fractioning."

Supposedly, if you've got a typical canister of gas (i.e. containing propane and some form of butane), in cold weather (temps below the vaporization point of all but the propane), only that fraction of the fuel that is propane will burn. Supposedly.

Here's an example of the myth: You have a canister that is 70/30 butane/propane. Propane vaporizes at -44F/-42C; butane at +31F/-0.5C. Now, say it's 20F/-7C out. According to the myth, only 30% (that fraction of the mix that is propane) will burn off.

That's the myth.  What really happens?  Well, take a 70/30 canister out in 20F/-7C weather and burn it until it's empty. Now weight it. You'll find the weight is lower than if only 30% of the fuel had burned off.

Why? Well, when you mix liquid hydrocarbons, they combine to form a blend. The blend has properties that lie "between" the properties of the constituent fuels. For example, the boiling point of a 70/30 blend of propane and butane will have a boiling point between -44F/-42C and +31F/-0.5C. The math is non-trivial, but if you know the formulae, you can calculate the resultant boiling point. In this case, a 70/30 blend has a boiling point of about 0F at standard pressure (1 atmosphere/1013mBar).

Now there is a little bit of a catch to all this. This "blend" of liquid hydrocarbons in a canister of gas (recall that there's so much pressure inside a cansiter that our gasses liquefy) still has two distinct molecules in it: Propane molecules (C3H8) and butane molecules (C4H10). The propane molecules have a higher vapor pressure than the butane molecules. In other words, the propane molecules tend to vaporize more than the butane molecules in the blend. How does a canister typically work? Well, you draw vapor off the top, and then more of the liquid portion of the fuel vaporizes to replace the drawn off vapor. If the propane is what most readily vaporizes, then the propane will be removed from the blend more rapidly than the butane. This is called "preferential" vaporization. Because the propane is vaporizing faster than the butane, your blend will change over time as the canister empties.  As the blend changes, so will the vaporization point.  Toward the end of the life of the cansiter, all the propane will be gone and only your secondary fuel will remain.

Uh, isn't this "preferential" vaporization the same as "fractioning?"

No, not at all. Remember that the myth of fractioning calls for only the propane to burn leaving behind all of the butane. What happens in reality is that the blend vaporizes some butane and some propane throughout the life of the canister until the propane is gone. Yes, you will reach a point where all of the propane is gone and only butane remains, but the fact of the matter is that you will be burning off far more fuel than if only propane alone were burning.

With fractioning (if it were true), you could only burn of 30% of the fuel in a 70/30 canister. With preferential burning, you burn more like 75% of your fuel before you wind up with nothing but butane left (the actual amount burned varies with altitude and temperature of course).

This brings up two important points:
1. Don't use canisters with regular butane in cold weather. Eventually all your propane will burn off, leaving behind whatever else is in your canister. If you've got isobutane (vaporizes at +11F/-12C) as your secondary fuel you've got a 20F (10C) degree advantage over a canister that has regular butane (vaporizes at +31F/-0.5C) as its secondary fuel.

2. Stoves that can handle running with the canister upside down (inverted canister stoves) draw fuel off the bottom of the canister. If you're drawing fuel off the bottom, you're only drawing liquid. If you're not drawing vapor, then it doesn't matter which fuel vaporizes at what rate. Inverted canister stoves start and end with the same fuel blend. If you start with 70/30, you end with 70/30, and your vaporization point stays low, allowing you to run your stove in much colder weather than a conventional upright (screws onto the top of the canister) gas stove. With an inverted canister stove, you can burn all of your fuel in cold weather (assuming that your blend's vaporization point is sufficiently high for the weather).

So, there you have it: What's really going on in that canister of yours in cold weather. I hope this puts the myth of "fractioning" to bed.

I thank you all for joining me on another Adventure in Stoving,

HJ

Related articles and posts:

Monday, April 9, 2012

Wood Cooking Clean Up

Ever find yourself holding back on using a particular pot or pan for wood cooking?  I mean they do get pretty darned black if you use them on a wood fire.  Sometimes I hesitate to use a pot I usually use with gas or alcohol on a wood stove because I don't want to get the darned thing all black.

Well, hold back no longer.  There's a simple trick out there that can get your pot clean again after cooking on a wood fire.  The trick?  Dish soap.
Putting a thin layer of dish soap on a pot before cooking with wood helps tremendously with clean up
Yep, that's right, just simple old dish soap.  Smear on a thin layer before you head out.  A little dish soap makes clean up go so much easier.

Why bother you say?  It's just going to get dirty again?  Well, and that is one way to handle it.  You could just pack your blackened pot in a sealed plastic bag so soot doesn't get all over.  But I use my pots with multiple fuels (gas, liquid, alcohol, wood, and hexamine).  A coating of soot will insulate your pot from the flame, and you'll have to use more fuel to heat things up.  So, for me, when I'm done with some wood cooking and want to switch to another fuel, I clean my pot.

How well does it work?  Let's have a look.

I'm just going to use an old scrubber type sponge here.  You probably could use steel wool on a steel or titanium pot.  A word of warning:  Whatever you use to clean, you're going to get it very dirty.  You'll probably want to throw the scrubber sponge away afterwards so it won't get other things dirty.  Either that or you'll have to have a designated scrubber sponge for really dirty clean ups.

So, here's my pot.  Pretty black.  Just waiting to get all over the inside of my pack, and pretty inefficient since heat is going to have to penetrate that coating before it heats the pot.
A rather sooty pot that has been used on a wood fire
Let's try a quick scrub with some soap and hot water.
A few scrubs, and bare metal starts to appear
Say, that's not too shabby for a few quick scrubs with an old scrubber sponge.  Makes quite a difference.

Let's try to clean the worst spot, the bottom of the pot.
Quite a marked contrast between the cleaned and the uncleaned sections of the pot
Hey, now that's quite a difference between the upper half of the pot that I've cleaned and the lower half that I have not.

Now, I'd be a liar if I said that it came off like magic.  Nope; it just doesn't work that way.  It takes some real elbow grease.  And, even when I finished cleaning the pot, there were still some little spots of black in the cracks and such.  But try cleaning a pot that's been used for wood fired cooking without first putting some dish soap on it.  The soot is not going to come off anywhere near as easily.

So there's your wood cooking clean up tip:  Smear a little dish soap on the exterior of your pot before you start cooking.  You'll be glad you did come clean up time.

Thanks for joining me on another Adventure In Stoving,

HJ