A lot of UL folk tend to use titanium cookware coz of its light weight and maybe ease of cleaning.
But because titanium is such a poor heat conductor compared to aluminium don't you tend to use and therefore carry more fuel, thus losing any weight gain from the cookware ?
Registered: 09/07/04
Posts: 172
Loc: Washington DC area
I don't know about weight from fuel.... I always carry aluminum cookware. It's cheap and it cooks really well, particularly for cooking eggs and hash browns in the morning it works so much better than Ti for actual cooking that it's worth it. Al is pretty light stuff, I can't imagine the weight penalty is significant unless you're seriously anal retentive about weight (admittadly many of us are!).
But because titanium is such a poor heat conductor compared to aluminium don't you tend to use and therefore carry more fuel, thus losing any weight gain from the cookware ?
While that's certainly true, titanium pots are generally thinner than aluminium pots. On the whole, I don't think there's a significant difference.
That said, I use an aluminium pot because it's light enough with excellent dimensions and I haven't come across a titanium pot good enough to justify it's price (here in Finland there's not quite as much to choose from and ordering from the net would be even more expensive).
Ti is a poor heat conductor per mass compared to Al. I use both type of pots. I have not noticed a difference in boil times. This is probably because the Ti pots are thinner than the Al (noted from trae also).
I like Ti better because it’s a little more ding, scratch, and crush resistant than certain Al cook wear.
A lot of UL folk tend to use titanium cookware coz of its light weight and maybe ease of cleaning.
But because titanium is such a poor heat conductor compared to aluminium don't you tend to use and therefore carry more fuel, thus losing any weight gain from the cookware ?
Ti Specific heat: 0.52 J/gK Al Specific heat: 0.90 J/gK
This would seem to indicate that Ti heats up MORE easily than Al. Maybe specific heat isn't the only factor? I'm not sure.
I don't think those numbers are correct. I found a table showing Al having a thermal conductivity of 128-180 W/mC (depending on alloy) and Ti of 15.6, meaning aluminimum conducts heat as much as 11.5x greater than titanium.
The difference is pretty easy to demonstrate in the field. I can pick up a relatively tall uncovered Ti cookpot from the stove w/o using a pot lifter, as the top edge will only be warm, but an aluminum pot will burn the bejezus out of me if I try a similar stunt. Similarly, an aluminum cup of hot coffee or chocolate will burn my lips; titanium is quite comfortable.
In practice, Ti pots are so thin I've never found a measureable difference in boil times comparing similarly sized, covered Al and Ti pots. The net flux seems the same, so I've concluded there's no efficiency difference WRT fuel use. Pot shape, a tight lid and an effective windscreen have far greater effects than pot material.
The biggest difference is Ti pots have much more concentrated hot spots when on the stove, making it much tougher to brown and simmer foods without burning.
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A lot of UL folk tend to use titanium cookware coz of its light weight and maybe ease of cleaning.
But because titanium is such a poor heat conductor compared to aluminium don't you tend to use and therefore carry more fuel, thus losing any weight gain from the cookware ?
Ti Specific heat: 0.52 J/gK Al Specific heat: 0.90 J/gK
This would seem to indicate that Ti heats up MORE easily than Al. Maybe specific heat isn't the only factor? I'm not sure.
Registered: 03/27/04
Posts: 144
Loc: Washington, DC
Complicated problem but just looking at materials properties:
I think there is a confusion of specific heat (the amount of energy to raise the temperature one degree of a hunk of material therefore J/C/kg) and thermal conductivity (how quickly heat moves through a material - W/m/C).
It takes a bit more energy to heat up the Al than it does the Ti - but the heat will be more evenly distributed in the Al. However, it takes much more energy to raise the water by one degree c since: 1.) There is a lot more of it -3 oz pot vs 16oz of h20 2.) the specific heat of water ~4.1/g/c -> more than 4 times more than Al. assuming a 4oz Al pot and a 3oz ti pot with two cups of water (16oz) Al pot: 113g Al*77C*0.9J/g/C = 7858J Ti pot: 85g Ti * 77C *0.5J/g/C = 3272J
Water in the pot: 453g h2o*77*4.1J/g/C = 143200J
So a difference of ~3% more to heat up the Al+h20 vs the Ti+h20. If you are measuring out your fuel within 3% you are spending too much time measuring fuel.
All in all, Al gives more even heating (fewer hotspots), Ti should technically give you a more efficient heating, but these efficiencies are so negligible that it is not even worth trying to compare, pot/stove/windscreen design plays a much more important role by far, but Ti will save you some weight, gain some strength, and loose you more dollars.
Titanium is lighter than aluminum. - just look at how much lighter your wallet is when you use it compared to the guys packing 10 dollar aluminum pots or canpots.
but Ti will save you some weight, gain some strength, and loose you more dollars.
Weight for weight Ti is stronger but most Ti pots are quite a bit thinner than Al pots, so maybe strenght gain is lost ?
I've also heard that if you heat a Ti pot empty, like you can with SS before you put water in them to get a quicker boil going, you can burn holes in the Ti pots or when heating a Ti pan empty without somekind of grease in it for baking could also be troublesome, deforming. Anyone experienced problems like this ? This what i've been told by people who work in outdoor shops.
Probably the thicker AL pots could handle a bit of preheating but a thinner one would probably deform as well ?
The $$ you save with aluminum will pay for your assisted living when you get Alizimers from aluminum contamination!
I think this is still very dubious this claim and hasn't this been cleared a long time ago ? No more use of tin foil in the kitchen then <img src="/forums/images/graemlins/smirk.gif" alt="" />
but Ti will save you some weight, gain some strength, and loose you more dollars.
Weight for weight Ti is stronger but most Ti pots are quite a bit thinner than Al pots, so maybe strenght gain is lost ?
I've also heard that if you heat a Ti pot empty, like you can with SS before you put water in them to get a quicker boil going, you can burn holes in the Ti pots or when heating a Ti pan empty without somekind of grease in it for baking could also be troublesome, deforming. Anyone experienced problems like this ? This what i've been told by people who work in outdoor shops.
Probably the thicker AL pots could handle a bit of preheating but a thinner one would probably deform as well ?
The melting point for Titanium is about 3135F and about 1220F for aluminum.
Registered: 03/27/04
Posts: 144
Loc: Washington, DC
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The melting point for Titanium is about 3135F and about 1220F for aluminum.
Yeah - but they will both burn (oxidize) at temperatures lower than melting in a O2 rich environment. I wouldn't be surprised if the uneven heating in Ti did warp it a bit on excessive heating.
Regarding the higher strength with Ti versus thinner Ti: Ti is about 2x as strong as Al alloy (800+MPa vs 400MPa yeid strength). I'm guessing that the pots are not 2 times thinner. Besides, I'm pretty sure that I could fairly easily bend my Al pot, but I would have to work a lot harder with Ti. Anyone want to donate a SnowPeak mug for science?
I knew all those materials science classes would pay off one day.
I ga-ron-tee you cannot, will not, burn up your titanium pot on any backpacking stove. I've heated mine to an orange glow and yes, it discolors in a kewhl rainbow fashion, but that's it. The metal is so thin that it takes mere seconds for this to occur on a gas stove with a narrow flame. I've learned to put the oil in first.
Ti pots dent and bend much less readily than aluminum of equal weight, which is probably their biggest advantage. Shop the sales and the price isn't all that bad.
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The melting point for Titanium is about 3135F and about 1220F for aluminum.
Yeah - but they will both burn (oxidize) at temperatures lower than melting in a O2 rich environment. I wouldn't be surprised if the uneven heating in Ti did warp it a bit on excessive heating.
Regarding the higher strength with Ti versus thinner Ti: Ti is about 2x as strong as Al alloy (800+MPa vs 400MPa yeid strength). I'm guessing that the pots are not 2 times thinner. Besides, I'm pretty sure that I could fairly easily bend my Al pot, but I would have to work a lot harder with Ti. Anyone want to donate a SnowPeak mug for science?
I knew all those materials science classes would pay off one day.
Registered: 03/27/04
Posts: 144
Loc: Washington, DC
Its got a whole heck of a lot more oxygen than any other atmosphere that I know of. 20% isn't bad. I do know that if you are getting Ti red hot, you are absorbing oxygen into the metallic structure, and in the end, you will make your pot more brittle. Probably not a big enough problem to worry about with a pot though.
Its got a whole heck of a lot more oxygen than any other atmosphere that I know of. 20% isn't bad. I do know that if you are getting Ti red hot, you are absorbing oxygen into the metallic structure, and in the end, you will make your pot more brittle. Probably not a big enough problem to worry about with a pot though.
I'm not really planning on using my Ti pot in other atmospheres. <img src="/forums/images/graemlins/grin.gif" alt="" />
According to this link, Titanium doesn't burn in atmospheres with lower than 35% oxygen. Also, Ti alloys are fairly resistant to oxidation under about 1200F. Link
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Titanium has excellent resistance to gaseous oxygen and air at temperatures up to about 700°F (371°C). At 700°F it acquires a light straw color. Further heating to 800°F (426°C) in air may result in a heavy oxide layer because of increased diffusion of oxygen through the titanium lattice. Above 1200°F (649°C), titanium lacks oxidation resistance and will become brittle. Scale forms rapidly at 1700°F (927°C). Titanium resists atmospheric corrosion. Twenty year ambient temperature tests produced a maximum corrosion rate of 0.0010 mpy (2.54 x 10-5 mm/y) in a marine atmosphere and a similar rate in industrial and rural atmospheres.
Caution should be exercised in using titanium in high oxygen atmospheres. Under some conditions, it may ignite and burn. J.D. Jackson and Associates reported that ignition cannot be induced even at very high pressure when the oxygen content of the environment was less than 35%. However, once the reaction has started, it will propagate in atmospheres with much lower oxygen levels than are needed to start it. Steam as a diluent allowed the reaction to proceed at even lower O2 levels. When a fresh titanium surface is exposed to an oxygen atmosphere, it oxidizes rapidly and exothermically. Rate of oxidation depends on O2 pressure and concentration. When the rate is high enough so that heat is given off faster than it can be conducted away, the surface may begin to melt. The reaction becomes self-sustaining because, above the melting point, the oxides diffuse rapidly into the titanium interior, allowing highly reactive fresh molten titanium to react at the surface.
Titanium burns when heated in air 610 °C (1,130 °F) or higher, forming titanium dioxide.[6] It is also one of the few elements that burns in pure nitrogen gas (it burns at 800 °C or 1,472 °F and forms titanium nitride, which causes embrittlement).[23] Titanium is resistant to dilute sulfuric and hydrochloric acid, along with chlorine gas, chloride solutions, and most organic acids.[2] It is paramagnetic (weakly attracted to magnets) and has fairly low electrical and thermal conductivity.
Registered: 03/27/04
Posts: 144
Loc: Washington, DC
I didn't know about the 35% O2 for burning, thats interesting.
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Further heating to 800°F (426°C) in air may result in a heavy oxide layer because of increased diffusion of oxygen through the titanium lattice. Above 1200°F (649°C), titanium lacks oxidation resistance and will become brittle.
This is what I was referring to above. I'm guessing that a unfilled pot on a pocket rocket could very easily get up to 426C and could get to 650C+ (a propane torch can reach 2000C). Of course the oxidation numbers are not a switch and time exposure has a lot to do with this. But you can do some damage to your pot.
All of this just goes to show, whatever the material (unless its ceramic coated Ni-based superalloy, which would be one heavy, expensive pot, but might make a decent jet turbine blade) don't leave an empty pot on a burner turned on high.
In practice the weight and heat conducting properties are very comparable, considering the Titanium can be thinner. The titanium has a definite edge in heat resistance, but aluminum is fine as long as there is water in it. Both are safe. The Alzheimer Society says that aluminum is not a cause, but you should probably cut down on processed cheese and antacids. Aluminum is probably better environmentally, because it is so abundant, but if you were to buy a titanium pot that you keep for life is probably better environmentally than going through countless aluminum cans because you like to keep experimenting like I do. Biggest issue with Aluminum Beer Can Pots is that they are coated with BPA containing epoxy resin, though not as high as with food cans, and way less than Polycarbonates. Does anyone know if there are uncoated aluminum beer cans?
It's coated to protect the thin aluminum from the contents. Otherwise it will perforate, evidently within a few days.
I don't know anything about the coatings themselves. I suspect they're heat-resistant, since a lot of food products are canned hot. But are they all? Who knows? We do know they resist acids and alcohol.
Uncoated/unanodized aluminum oxidizes quickly. Removing the coating from a can will probably lead to its quick demise; of course, it doesn't cost anything to experiment!
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Is that for reasons of flavour, shelf life, or safety? I think they only started coating them 20 years ago.
I use only coated aluminum for my cookware. In particular I use a JetBoil 1.5 L. pot B/C its bottom "Flux Ring" corrugated heat exchanger & neoprene side cozy really make the most efficient pot I've found. It actually heats 2 cups of water faster than my buddy's narrower original Jetboil pot beause it has a wider base.
Also the Flux Ring heat exchanger around the botttom works so well to spread heat & capture it that, when the pot has only one cup H2O left it boils around the outer edge, above the Flux Ring!
I bought a Japanese made Ti skillet. AAArrrggghh! It has a center hot spot and will NOT spread heat evenly with any of my 6 stoves. Sell it to you for $5. You pay shipping.
Eric
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"There are no comfortable backpacks. Some are just less uncomfortable than others."
Thx for the offer on the ti-skillet, but just bought myself a new trangia UL hard anodised 1.75 l pot, weighs only 4.2 ounces. I've been experimenting with it and i'm not quite sure what' happening with this new pot. With my alky, well one of'em <img src="/forums/images/graemlins/wink.gif" alt="" />, i get a small boil going, it makes a sound i've never heard when boiling. Sounds more high pitched and also i don't get a real 'rolling' boil going either.
Also tried it on my msr canister stove, think it's called a simmerlite, and the pot discolored in the center, it now has a rainbow color center spot.
I've noticed the material is thinner than older trangia 1l non-stick pot, with which i get a much better boil going, using the same setup. Prob smaller diameter and more even heat distribution does the trick.
I've also been experimenting with a food can, holds 900ml and to my big supprise, i'm getting the best boils going in these things. Takes longer than any of my other pots, but it's the strongest. Probaby coz it steel and the smaller diameter. Anyome use something like that for cooking pot ? Also it's quite light. The hole shebang, pot-lid--stove-potstand-primer pan-windscreen-potgrip weighs 124 grams.
And to my big shame i bought myself a new canister stove. <img src="/forums/images/graemlins/smirk.gif" alt="" /> Just couldn't resist the very tempting offer on the brunton crux. But isn't it the coolest stove around. <img src="/forums/images/graemlins/cool.gif" alt="" />
Geez I love my Ti skillet. <img src="/forums/images/graemlins/smirk.gif" alt="" /> I use it for a plate and often, just to prove a point, I make beautiful pancakes for breakfast, over a campfire <img src="/forums/images/graemlins/grin.gif" alt="" />.
You have to pretty much hold the pan handle in your hand and flip often... <img src="/forums/images/graemlins/wink.gif" alt="" /> Jim <img src="/forums/images/graemlins/cool.gif" alt="" />
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These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.
Yeah, I love to make buckwheat cakes in camp & fry up some rehydrated freeze-dried sausage or reheat some turkey bacon I've cooked at home. (Real bacon if it's winter camping, where I need the fat.) But I make 'em on a coated aluminum fry pan.
I keep honey & jam in refillable tubes inside a Ziploc, and in winter they have to stay warm in a chest pocket to stay useable.
Eric
_________________________
"There are no comfortable backpacks. Some are just less uncomfortable than others."
Well, I always learn everything the hard way. My son and I just completed a three night trip to the Ponca wilderness area. I carried 3 stoves. A trangia and 2 pop can stoves. The pop can stove did the best job. The trangia used to much fuel and burned out to fast. As far as cookware, I carried a cheap coleman $5 that did great for making pancakes (good but what a mess to clean). The down side to that cheap set was the aluminum cup. Hot to hold and cooled to fast. Same with the bowl/plate. I will replace with plastic. The shining light on the whole cookset was the heine pot setup with a cone windscreen. My pack weight was right at 30 lbs with water. I figure I can get it down to 20 the next trip.
Registered: 09/07/04
Posts: 172
Loc: Washington DC area
Camp pancakes are one of the best things ever. Turning them without a spatula is a bit of a challenge but it can be done.
The best is hiking during blueberry season. For my week long trip to Resurrection Pass a few years ago (that's my avatar pic - part of a big panorama with me in the pass) it was mid-August. We stopped and picked berries for at least an hour. Sure, only half of the berries went into the pot, but there was still enough for a blueberry pancake feast the next morning. One of the best trail breakfasts ever!
Fresh eggs are another staple which also requires a more utilitarian cookset. Eggs will last a few days ouside the fridge, they are heavy to carry compared to powdered, but it is so worth it when you wake up. An aluminum packpacking percolator is another cook luxury I enjoy!
Phil I have 6 blueberry plants in my backyard. <img src="/forums/images/graemlins/wink.gif" alt="" /> Last year we got a lot of big tastey fruit. <img src="/forums/images/graemlins/grin.gif" alt="" />
I know pancakes while camping requires a blackbelt in camp cookery. <img src="/forums/images/graemlins/smirk.gif" alt="" /> All I can say is - use a low fire, preheat your pan, use oil, keep the pan moving, carry a spatula, and flip often. As lng as you keep flipping, they don't burn. SO anyway I guess we know the secret now huh? - do you have a spatula? <img src="/forums/images/graemlins/grin.gif" alt="" />
Oh yeh - look if you want really nice pancakes and you already have eggs, oil, spatula, skillet - take maple syrup. We now carry the litle bottle on the annual gourmet trip - its great in coffee or tea or anyplace you need a sweetener. <img src="/forums/images/graemlins/wink.gif" alt="" /> Jim <img src="/forums/images/graemlins/cool.gif" alt="" /> Disclaimer - I would personally never ruin a good cup of java with sweetener, just cream. <img src="/forums/images/graemlins/tongue.gif" alt="" />
_________________________
These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.
Titanium cook ware is very thin. In all heat transfer equations you have to divide by the thickness of the material, thus the absolute heat transfer numbers for the material [do you have the correct alloy BTW?] are insignificant. If you put two identical evernew pots one SS and one Ti on snow and pour an equal amount of hot water in them from one larger pan, the water in the Ti pan will cool more quickly. <img src="/forums/images/graemlins/grin.gif" alt="" /> One would assume that it is thinner. <img src="/forums/images/graemlins/tongue.gif" alt="" /> This might not be a good thing for cooking. <img src="/forums/images/graemlins/tongue.gif" alt="" />
Aluminum is nice because you can have a thicker pan which distributes the heat better, for the same weight. For a long time there was an aluminum scare so everyone used SS. Titanium is great for heating water in, and it can reach extremely high temps without "burning", much higher than steel, thus the usage in aircraft in extreme environments. It doesn't hurt a pan to "oxidise". It can be sand blasted or scoured clean with sand. <img src="/forums/images/graemlins/cool.gif" alt="" />
Frankly if you enjoy cooking and simmering - get aluminum, <img src="/forums/images/graemlins/wink.gif" alt="" />but I'd be be cautious of non-stick because if fluorocarbons get too hot they can give off deadly gas. Same with painted pans - I have one set painted with car exhaust header paint baked on it an oven, BUT in direct stove flame it gets hot enough to outgas. <img src="/forums/images/graemlins/blush.gif" alt="" />
Jim <img src="/forums/images/graemlins/cool.gif" alt="" />
_________________________
These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.
I'll go with alu for sure. I tried my food can pot setup with my msr canister stove and it takes a couple of minutes longer to get 500ml to a boil and uses more fuel in the proces.
Still not sure which alu pot though. I got a new trangia ul hard anodised alu but it's noticably thinner than my previous alu non-stick trangia pot. I guess this thinner alu pot wouldn't have such a good heat transfer ?
Also when i try to get a boil going it sounds sharper and higher pitched, don't know if this makes any sense to ya'all. Also tried it with my canister stove and it got me a nice rainbow colored spot in the middle of the hard anodised pot. Is this normal ?
I'll also ditch my potgrip and use one of my bandana's instead.
<< I guess this thinner alu pot wouldn't have such a good heat transfer ? >>
Actually the thinner one will transfer heat more easily, but the thicker one will spread the heat more as it passes through the metal. My Ti skillet [evernew] is only 10 thousandths thick.
<<Also tried it with my canister stove and it got me a nice rainbow colored spot in the middle of the hard anodised pot. Is this normal ?>>
Yes - the pan is a bit scorched. You can clean it and avoid it happening by keeping liquid water in the pan when it on the stove so the metal doesn't get up to the temperature of the flame. But it doesn't hurt anything - clean with sand or scouring powder. <img src="/forums/images/graemlins/cool.gif" alt="" />
<<I'll also ditch my potgrip and use one of my bandana's instead.>>
You might be sorry. Its like the reason I carry metal fork - it doesn't melt. Buy pans with light fold out handles instead. <img src="/forums/images/graemlins/laugh.gif" alt="" />
Jim <img src="/forums/images/graemlins/cool.gif" alt="" />
_________________________
These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.
Yes - the pan is a bit scorched. You can clean it and avoid it happening by keeping liquid water in the pan when it on the stove so the metal doesn't get up to the temperature of the flame.
It happened when i boiled water in it.
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But it doesn't hurt anything - clean with sand or scouring powder. <img src="/forums/images/graemlins/cool.gif" alt="" />
I think using sand is the best cleaning method. But a while back i was told that the anodisation proces puts a very thin coat on alu pots, which can be damaged like non-stick, but not as easily. Wouldn't using sand start to sand away this coat little by little ?
In fine powder form, or filament form, many metals burn in air. Fine steel wool is an example.
It is called the surface to volume ratio. After all, combustion starts at the surface where hot metal and oxygen meet.
Many of these "metal to metal" comparisons are in danger of combustion because of hot air being freely circulated. <img src="/forums/images/graemlins/shocked.gif" alt="" />
Magnesium burns quite readily and not just in foil form. Just check with any insurance agent about what it costs to insure a plant that machines mag. Or check with a sailor who has done flight deck duty. But that's not to say it can't be near an open flame, it takes more than a flick of your Bic.
I had never heard of titanium burning prior to this thread. I've just never worked with it. So while the links I posted do indicate that it's plausible, I think it would require that someone be pretty careless. When your pot is glowing red, it's probably close to the right temperature. I can't imagine letting my pot get there, though.
This article is probably not "hot air" by amateurs discussing metallurgy.
INTRODUCTION
The titanium industry dates back to the turn of the century, although commercial production of the metal actually started in about 1950. By the end of 1999, the industry was producing more than 100 million pounds per year. Early on, safety problems arose from a lack of knowledge regarding furnace design and related explosions. The knowledge at the time was based on steel technology, and the hydrogen explosions were a completely new problem. When molten titanium reacts with water, the titanium metal breaks down the water, absorbing the oxygen and liberating the hydrogen, which results in a major explosion. During the first five years of the industry, furnace explosions killed six employees.
The next problems that plagued the industry were fire and explosions from sponge and fines fire, which killed four employees. The third problem was confined space entry. Five fatalities have resulted from argon, nitrogen, and other inert gases.
METAL FIRES AND EXPLOSIONS OCCURRING IN THE HANDLING OF FINES, SPONGE, AND TURNINGS
The most prevalent accident occurring in the industry during the past 50 years has been metal fires. The major cause is poor housekeeping and inexperienced operators. Using the fire triangle as a base, there is always fuel for the fire when working with finely divided metals. When handling the material in the atmosphere, there is always oxygen available. Thus, the controllable leg of the triangle is the ignition source, even though the extent of the loss can be controlled by design and housekeeping.
In the past year, the titanium industry has experienced five major fires at a cost of well over $1 million. All were preventable. We can do better.
* A magnesium fire at Timet Henderson was caused by charging molten magnesium into a wet mold at a cost of $200,000 and two injuries. * A dust-collector fines fire at the Albany Casting Plant was caused by housekeeping and a bad dust collector at a cost of $250,000. No injuries. * A dust-collector fire at THT was caused by mechanical problems at a cost of $150,000. No injuries. * A magnesium fire at Timet Henderson was caused by 1,000 pounds of spilled molten magnesium metal that reacted with water from melted cooling lines at a cost of $300,000 and months of lost production. No injuries. * A fines fire at Gemeni, a powder pressing plant in Albany, Oregon, was caused by static electricity from a bad electrical motor. There were excessive amounts of powder stored in the area. The cost was $450,000; the company went out of business. No injuries.
n 1974, an employee was working as a press and weld operator. He was running titanium sponge through a 24 to 1 splitter to produce containers of sponge for feed to the press. The material was a blend of Kroll sponge and Hunter process sponge. (The latter material was very fine due to the sodium-reduction manufacturing route.) With 30% of the material split, the material began catching in the tote bin. The operator went to the top of the splitter, which was 30 ft. above ground. He used a metal bar to rap the tote bin to get the metal to flow out of the bin. Evidently, he created a spark that ignited a dust cloud of titanium fines in the area. In an instant, the fire flashed to the ground level and back up. He was completely engulfed in flames and died from his injuries. The ensuing fire is depicted on the cover of this issue of JOM.
The investigation of this accident revealed several shortcomings of the system. First, the dust-collecting system was not adequate to handle the fines content of this material mix. Second, the use of the bar was an ignition source. Third, employees should not be allowed to work in dangerous areas.
Following this accident, the dust-collector system was replaced. The bar was taken out of the area, and procedures were established to keep operators from going to the top of the splitter when it was in operation.
Three lessons were learned from this accident.
* A cloud of metal powder can ignite and burn with explosive force. * A mechanical spark is enough to ignite a dust cloud. * Operators must be kept out of harm’s way.
There have been other significant metal fires, related fires, and explosions experienced in the industry. When it is realized that even wheat flower in a dust cloud can cause a catastrophic fire, all efforts must be taken to eliminate the dust cloud and the ignition source.
Chemically, titanium has an enormous affinity for oxygen. This results in a thin film of titanium oxide being produced almost instantaneously on the surface of the titanium when exposed to the atmosphere. The titanium-oxide film is inert and protects the underlying metal from further attack.
When a titanium-powder particle is heated to a certain temperature (known as the ignition point), the mass of the particle is so small that the entire particle may oxidize almost instantly. Thus, a pile of such particles will burn. Since sponge particles are much smaller in mass than atomized or granular particles, they will ignite more readily and burn faster than the coarser types of powder.
Fine particles of titanium powder, like some organic powders, such as flour, starch, and coal dust, are easily dispersed in air, where their light mass allows them to remain suspended. Like particles in a pile, they will burn when the ignition temperature is reached; but when dispersed in the air (mixed with oxygen) in a certain proportion, the burning extends from one particle to another with such rapidity (pressure rise in excess of 20,000 psi/s) that a violent explosion results.
Laboratory tests by the US Bureau of Mines and others have established the proportions required for an explosion. They extend throughout a wide range, and very little titanium powder is needed. Very small amounts of energy are required to ignite certain mixtures of titanium powder and air. In some cases, energy as low 25 millijoules may cause ignition.
While my science degrees were in mechanical engineering (BSME, MSME) and not metallurgy, I have gained a lot of experience working in the industry for the past 25 years. I don't think it's accurate referring to me as an "amateur" in the field, or to my contributions to the discussion as "hot air."
It takes a fair amount of heat to ignite mag, but once lit it sustains itself and is very difficult to extinguish. I've seen it demonstrated at firefighting school in the USN. The preferred method of extinguishing it is to push the aircraft off the flight deck and into the water.
I'm skeptical as to whether one can ignite a titanium pot over a backpacking stove. However, the information is useful. No sense in being careless.
I'm, uh, "vintage" enough to have had a chemistry set of the dangerous and fun kind. It helpfully supplied magnesium strips to light afire using the equally helpful alcohol burner. Man, does it ever burn! And water has no effect on it once lit.
That said, Coleman's X stoves have magnesium burner legs, so it's not as though the stuff's going to burst into flames in the presence of heated language :-) Still, there's probably a reason you don't see actual magnesium "mag" wheels these days.
A friend who used to own a prototype machine shop did have to take extraordinary care when handling magnesium and storing/disposing the turnings. Aluminum's also a hazard, but not as severe.
He also worked with titanium. I don't recall what he had to do with the turnings, but it was very challenging to work with. I'll ask next time we go hiking.
I'm, uh, "vintage" enough to have had a chemitry set of the dangerous and fun kind. It helpfully supplied magnesium strips to light afire using the equally helpful alcohol burner. Man, does it ever burn! And water has no effect on it once lit.
That said, Coleman's X stoves have magnesium burner legs, so it's not as though the stuff's going to burst into flames in the presence of heated language :-) Still, there's probably a reason you don't see actual magnesium "mag" wheels these days.
The reason may well have nothing to do with what we are discussing.
Magnesium ladders, once popular, were replaced by much cheaper aluminum ones.
Magnesium IS lighter than aluminum, but aluminum alloys are superior in strength and fatigue. The end strength to weight ratio doesn't look particularly good for magnesium.
There must be a reason why over the last 80 years, the lighter (expensive) magnesium alloys haven't displaced the (heavier) cheaper and stronger aluminum alloys.
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A friend who used to own a prototype machine shop did have to take extraordinary care when handling magnesium and storing/disposing the turnings. Aluminum's also a hazard, but not as severe.
Many metals are a hazard when the surface area is high and the volume is low, such as the infamous magnesium ribbons and machine turnings as well as fine powders.
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He also worked with titanium. I don't recall what he had to do with the turnings, but it was very challenging to work with. I'll ask next time we go hiking.
While my science degrees were in mechanical engineering (BSME, MSME) and not metallurgy, I have gained a lot of experience working in the industry for the past 25 years. I don't think it's accurate referring to me as an "amateur" in the field, or to my contributions to the discussion as "hot air."
As a retired Materials Scientist/Metallurgist (BSEng, MS, PhD), with long experience (35 years) in the aerospace industry, it is almost always true that the engineers I have worked with have effectively only "amateur" knowledge of the field. There are some exceptions, chemical engineers often "Know" metals by more than knowing their names But, you almost expect that from the word Chemical.
I suspect that the typical ME is doomed to be a relative amateur in materials much as a mathematician is doomed to be a relative amateur in ME. Even though mathematics is so essential to the ME field.
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It takes a fair amount of heat to ignite mag, but once lit it sustains itself and is very difficult to extinguish. I've seen it demonstrated at firefighting school in the USN. The preferred method of extinguishing it is to push the aircraft off the flight deck and into the water.
The relevant issue of much of metals burning is the surface area to volume ratio. The surface area is what supports the combustion, and the volume is the "Thermal Damper" that tries to cool the surface down and retard combustion. There is also the issue of the very hot temperatures at the combustion front.
If there isn't enough volume (fine particles or thin wide ribbon), the combustion rate tends to go sky high (because of the high temperatures) with no ability to self extinguish by heat transfer to the colder interior of the combusting item.
When highly reactive metals burn in bulk or fine form, the temperatures are often such that any water sprayed onto them will be decomposed and the oxygen contained in the water will be used to react further with the hot burning metal. In other words, water can aggrivate the burning, not extinguish it.
That is one reason why pushing the burning aircraft off the deck is wise.
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I'm skeptical as to whether one can ignite a titanium pot over a backpacking stove. However, the information is useful. No sense in being careless.
I too am skeptical about the ignition of a Ti pot over a backpacking stove, but if it is thin enough and the heat is localized and intense enough......
So far, there don't seem to be any reports of burning Titanium cookware.
For some reason, this discussion suddenly reminds me of a famous quote from H Ross Perot:
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(contrasting the cultures of his former company, EDS, and General Motors, which had acquired EDS)
The first EDS'er to see a snake kills it. At GM, first thing you do is organize a committee on snakes. Then you bring in a consultant who knows a lot about snakes. Third thing you do is talk about it for a year.
[quote] I suspect that the typical ME is doomed to be a relative amateur in materials much as a mathematician is doomed to be a relative amateur in ME. Even though mathematics is so essential to the ME field. [quote]
Well, I have to agree. Since I am finally an ME <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" /> my first year out of school has shown how little I know of materials. It seems a lot of what I do is material selection, and sometimes it is a lot of trial and error and hit and miss. <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" /> But, I have learned a lot about plastics this last year. <img src="/forums/images/graemlins/smirk.gif" alt="" />
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I've taken a vow of poverty. To annoy me, send money.
Well, I have to agree. Since I am finally an ME <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" /> my first year out of school has shown how little I know of materials. It seems a lot of what I do is material selection, and sometimes it is a lot of trial and error and hit and miss. <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" /> But, I have learned a lot about plastics this last year. <img src="/forums/images/graemlins/smirk.gif" alt="" /> [/quote]
I am unaware of any recent books that will speed up your learning curve. Plastics (polymers) have always been troublesome and the explanations of mechanical behavior in polymers have been of poor quality for as long as I tried to master them..
An old book, written by an automotive race driver (former) is "Engineer to Win" by Carroll Smith. It is really impressive, and only a few mistakes in the whole thing. Amazon.com link below. http://www.amazon.com/Engineer-Motorbook...&sr=1-1 pd_bbs_sr_1?ie=UTF8&s=books&qid=1209509084&sr=1-1
Another one, which appears to have a recent edition (that I haven't read) is " The New Science of Strong Materials or Why You Don't Fall through the Floor" (Princeton Science Library) 2006 by J. E. Gordon and Philip Ball . Available at Amazon.com
J E Gordon is an outstanding writer. Most people can't put these books down. Another classic, perhaps recently revised or at least reissued is: Structures: Or Why Things Don't Fall Down by J.e. Gordon (Paperback - Jul 8, 2003)
There is also Materials Selection in Mechanical Design, Third Edition by Michael Ashby (Paperback - Jan 26, 2005) which was excellent in the first edition, and I taught a class based upon it.
And, this too is new, and unread by me, but I greatly enjoyed his previous books on materials science..... Materials: Engineering, Science, Processing and Design by Michael Ashby, Hugh Shercliff, and David Cebon (Hardcover - Mar 30, 2007)
In one sense, all of the books above were gems by gifted men. Too bad we don't have more like them.
Good luck in becoming materials smart. By this time, it should be much easier than before, but I haven't myself seen & read the recent new books that would make it so.
The $$ you save with aluminum will pay for your assisted living when you get Alizimers from aluminum contamination!
I think this is still very dubious this claim and hasn't this been cleared a long time ago ? No more use of tin foil in the kitchen then <img src="/forums/images/graemlins/smirk.gif" alt="" />
I first heard of this "aluminum" allegation in 1996 and it was considered outmoded even then.
There are some things that people evidently just love to believe and repeat. Simple solutions to complex problems pan out not too well, mostly.
What an electronic memory is has been well known in detail for a long time.
What a human memory is, physically, is still unknown. No one has seen whatever change it is that occurs when a new memory is created in a brain.
Precisely what Alzheimer's is is still unknown. But we do know how to spell it, finally. <img src="/forums/images/graemlins/smile.gif" alt="" />
Registered: 04/26/08
Posts: 1
Loc: Utrecht, The Netherlands
A dutch backpackers magazine did a test a few years back, and the fastest was the MSR alpine set, slowest the Hard anodized Aluminium with 50% slower then the stainless steel. Ti was somewhere inbetween.
Registered: 03/27/04
Posts: 144
Loc: Washington, DC
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... Many of these "metal to metal" comparisons are in danger of combustion because of hot air being freely circulated. <img src="/forums/images/graemlins/shocked.gif" alt="" />
If it makes you feel better, I too have a PhD in MatSci, so I am not totally talking out of my, umm ear. But I have found that in the world of matsci, often practical experience (which you definitely have more of than me, I just do fundamental research) outweighs degrees when it comes to practical matters such as these. Just glad to have another metal-head on the boards.
Thanks for all the suggested reading. I will definitely try and add these to my collection and reading list. <img src="/forums/images/graemlins/wink.gif" alt="" /> <img src="/forums/images/graemlins/smirk.gif" alt="" /> <img src="/forums/images/graemlins/smirk.gif" alt="" />
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I've taken a vow of poverty. To annoy me, send money.
Precisely what Alzheimer's is is still unknown. But we do know how to spell it, finally. <img src="/forums/images/graemlins/smile.gif" alt="" />
Speak for yourself. <img src="/forums/images/graemlins/grin.gif" alt="" /> I am still working on that one. <img src="/forums/images/graemlins/wink.gif" alt="" /> <img src="/forums/images/graemlins/wink.gif" alt="" />
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I've taken a vow of poverty. To annoy me, send money.
Precisely what Alzheimer's is is still unknown. But we do know how to spell it, finally.
Unfortunately, I've been getting an up close and personal look at it the past three or four years. My father is afflicted with it (at least as far as doctors are able to diagnose it).
I have a hard time making jokes about it anymore. There's nothing funny about the ordeal.
Registered: 09/07/04
Posts: 172
Loc: Washington DC area
I'm not sure what speed has to do with this. My concern is how well the heat is dispersed so that I can actually cook my powdered eggs on my stove. I would rather have the heat evenly dispersed as opposed to hotspots in the pan which cause my powdered eggs and hashbrowns to burn in places where they are raw in others.
Hiya welcome. <img src="/forums/images/graemlins/smile.gif" alt="" /> I think maybe you may want to go research that test a bit. The people around here are pretty sophisticated and throwing around a few vague numbers is not gonna buy you a lot of credibilty. <img src="/forums/images/graemlins/laugh.gif" alt="" /> There are so many variables and have been so many tests that unless you can quote the test results, your input has little value - STILL thanks for sharing and don't go away with your feelings hurt. We always need new members with new ideas. <img src="/forums/images/graemlins/grin.gif" alt="" />
As people have said - there is more than heating water with speed to be considered while cooking. <img src="/forums/images/graemlins/grin.gif" alt="" /> Jim <img src="/forums/images/graemlins/cool.gif" alt="" />
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These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.
I'm working on the translation of the magazine test anand is talking about so all ya english folk can have a read. Not a lot of numbers or tech talk so the numbersfreaks or technicians amongs us will be dissapointed, but more a practical approach. Main theme is about which kind of cookware is the easiest to use in the backcountry, not necessarely the fastest cooktime or lightest.
No offense to anyone though, but imho just shows how uterly unimportant all this jabbering is. But i agree with food, in that humor can in part put things in perspective and make life's confrontations easier to handle and to get through them.
Oh, my humor is intact. But I can tell you that when someone jokes about having a "senior moment" or "early Alzheimer's," I just can't laugh. It's hard to come up with an analogy, it would be like someone joking about cancer when a loved one is terminally ill with it.
What keeps me in good spirits is remembering that my father had a long, happy life and he's surrounded by people that care. It's almost as if he's already died, because he's no longer the person he was.
I find anodized aluminum spreads pretty good. Although the stove itself has a lot to do with it. For instance, I can't make even pancakes with an MSR Pocket Rocket, but my buddy's Superfly and my Snow Peak Gigapower.
i really don;t care for titanium for actual cooking anything besides water.
I can tell you that I have both and the titanium would win hands down ever time for me. For me, it is easier to clean (non-stick aluminum sure isn't non-stick). Depends on the thickness of the pots and pans but I still think that titanium is lighter too. I just like the titanium better and I have used aluminum for thirty years before I started using titanium. The aluminum works great but the titanium works better for me...Hope that helps....Happy Trekking...sabre11004...
The first step that you take will be of those that get you there !!!!!! <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" />
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The first step that you take will be one of those that get you there 1!!!!!
That means that titanium can take approximately 60% more heat than aluminum huh??? That's the number that I got any way. When you are cooking directly over "fire" I think that I would still want the titanium...Hope that helps....Happy Trekking...sabre11004....
The first step that you take will be one of those that get you there !!!!! <img src="/forums/images/graemlins/wink.gif" alt="" />
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The first step that you take will be one of those that get you there 1!!!!!
I am a little confused. I don't really know what magnesium has to do with this conversation but I guess that I can roll with it. Besides I don't think that you will find many cooking utensils made out of magnesium any way. So again, what's the point? Any way...Hope that helps...Happy Trekking...sabre1004...
I am kind of like the matsci engineer. I am more interested in how they actually work, not the experience that others have with them. Conditions and many other things can have a play on all this stuff that is being talked about here...Including the experience of the hiker and the quality of all of his gear put together to for a well working kit for that individual...Hope that helps...Happy Trekking...sabre11004...
The first step that you take will be of those that get you there !!!!!! <img src="/forums/images/graemlins/tongue.gif" alt="" />
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The first step that you take will be one of those that get you there 1!!!!!
This and other threads keep having engineering and other credentials being passed around as criteria for having an informed opinion. Luckily, I have my advanced lightweight backpacking materials course from EU and some experience in gear building and testing. Hah!
What I think really matters is using a variety of cookware out there and figuring out what works. I wouldn't concentrate on the technical specs of why things work or don't work but rather what really happened when you fired up that 20,000 btu stove with the .6oz titanium pot. Fer example!
Lighten up everyone, especially here on the TLB!
<Earthling, this is your cue to make a joke>
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Listen to the trees in the wind
Sorry for the delay and typo's if any, but earning some extra cash for my next walk <img src="/forums/images/graemlins/wink.gif" alt="" />
Aluminium is dead, which type of pot ?
After a long walk or bike-ride there's nothing nicer than hot meal. And then there's nothing more annoying than scrubbing an hour to get the last bits and pieces from your pot. In short : which type of pot should you take with you on your travels ?
This is not a test to determine which is the best cook-set. This is a test though in which we try to find out from which material a pot should best be made of. There are roughly 3 different base-materials.
Most common pot is an AL one. AL doesn't weigh much, is durable and cheap and conducts heat reasonably. Cons : difficult to clean and vulnerable. Second most common material is SS. SS is strong, cheap and cleans easily, but has as biggest disadvantage that it's heavy. And then you've got TI pots. TI is superlight, strong, expensive and a bad heat conductor.
Relatively new is Hard Anodised AL : the AL has undergone a treatment in which the outer layer has been hardened. Hardened AL is stronger than steel, but still has the weight advantage.
To conclude : Duosal from Trangia. Duosal is a combination of AL on the outside and SS on the inside.
Just as at home there are outdoor cook-pot with an anti-stick coating. The brand- name Tefal is obvious, but actually we must talk about Teflon. Teflon is a brand- name from Dupont for a chemical combination Poly-Tetra-Fluoro-Ethylene or PTFE. Teflon has the property that other materials don't adhere tot its surface and thus making Teflon an ideal anti-stick coating. You'll encounter Teflon from Dupont is pots, but not in Tefal cookware - nowadays the most know producer of anti-stick coated cookware, has an own anti-stick coating.
The test Like we said, we're looking for the material that is the easiest to work with, not which brand is the best. The sets are chosen so we get an idea of the different materials. From every set we took 1 pot with a minimal volume of 1 litre. The test consists of 3 parts : Cook-time : on the home gas-stove we bring 1 litre of water to the boil and note it's time. Why on a home gas-stove ? Because then we aren't confronted with diminishing gas-pressure and thus the heat-output is constant for every pot. By the way, the cook-times should be viewed as an indication and in relation to each other. A real outdoor stove does deliver considerably more heat-output and thus shorter cook-times. The faster, the better for the material.
Burnfactor : in the pot, nice softly cooked macaroni was heated with a little bit of sunflower oil. In most cases heating meant baking and in a number of cases burning.
Cleaning : After the baking we looked how fast we could get the burned macaroni from the pot bottom. The easier, the better.
Bo-Camp AL The test : AL is light and cheap, but that's not all. When we baked the macaroni, it immediately got stuck to the bottom and started to burn. Afterwards it was barely removable. Scrubbing alone, it hurt the fingernails, and with a scrubpad we got the mac out. Plus a layer of AL, because the dishwater was quite gray. Our opinion : Light and cheap, these are the only advantages. There are a lot better pans for sale.
Tefal Bivouac AL + Non-Stick The test : These pans are also made of AL but it conducts a bit better than the average AL pot, therefore the quicker cook-time. The mac to burn didn't succeed ! The non- stick coating did it's work. The mac got crispy though. Cleaning was child-play : turn pot up-side-down and the mac fell out. Cleaning afterwards wasn't necessary, although according to the manufacturer you should. The only con : the pan is as slick on the outside bottom as it's on the inside and can therefore easily slide of your stove. Our opinion : Super ! Never again without and anti-stick coat in the outdoors.
------------------------------------------------------------------------------------------------------------------------ Gossip and backtalk Long there has been thought that PTFE in pots was poisonous when the coating loosened (flaked). This is a fable. As with the story of parts of AL would cause Alzheimer. Also for this there is no proof and thus falls under the column gossip and backtalk. ------------------------------------------------------------------------------------------------------------------------
Trangia Tundra Duosal The test : The pot is made of Duossal, a combination of AL on the outside and SS on the inside. The cook-time was average. The mac burned though and became stuck, but the cleaning went easily. With a pot-scrubber - that left a bit of scratches - everything came of in no time. In the same set is a pot and pan with a non-stick coating. Our opinion : Not the lightest, not the quickest, burned but easily cleaned. Duossal as pot material isn't all that crazy.
Anodised AL GSI Double Boiler The test : Anodising is a technique in which the AL surface is hardened. According to GSI it becomes twice as hard as the surface of AL. The long cook-time is largely due to the small diameter : the flames went up the sides of the pot. Pros : a high pot does retain the heat better. The mac burned quickly and was nicely scorched. Cleaning was, because of the small pot, a crime, but no AL-flakes came of. Our opinion : H-A AL is the new material in pots; it combines a low weight with durability. An anti-stick coating is a definite plus.
Optimus terra anodised aluminium with anti-stick coating The test : Just like GSI an anodised pot : the AL surface is hardened. Optimus has also added an anti-stick coating. The cook-time is average. This is the combination for baking cheese and mac. The mac got crunchy; but didn’t become stuck to the bottom. Cleaning was a pleasure. Empty the pot and wipe clean. Marginally better than the anti-stick coating from Tefal. On top of that the pot was more stable on the burner. Our opinion : Hard anodised AL with an anti-stick coating is the combo that from now on we will be taking on our trips. Functional, easy in every aspect, though a little heavy.
Snow peak multi compact TI The test : Ti is extremely light and strong and therefore seems an ideal material. Two buts : It’s expensive and is a bad heat conductor, you have to put more energy into the pot. And you have to carry this energy with you. The somewhat longer than average cooktime is explained by this. Baking the mac went quite well : it got stock rocksolid to the pot. Cleanig was hard, only AL performed worse. There were black spots left in the pot. Our opinion : TI is extremely strong, and allas, very precious, or shall we say expensive. Heat transfer is less compared to the cheap AL. Cleaning could be better, and black spots in an expensive pot.
MSR alpine classic SS The test : A fast cooktime and a somewhat higher weight. But to put it in the words of Cruijff (a famous Dutch football players for you folks who don’t know him), every advantage has it’s disadvantage. Tip for SS : first heat the pan and only then put your grease and meat in. Our opinion : fast, reasonably cheap, strong and heavy. Scorching and cleaning was easy.
Conclusion : The plain AL pot is finished. Yeas they’re light and cheap, but for the rest it’s a very old economy. SS pots are an option : durable, not to expensive but heavier than AL. TI weighs almost nothing, is strong and very precious. But heatconduction is bad. We’re really pleased with the anodised pots : strong, a little expensive, a little heavy and with an anti-stick coating easy to clean.
Here's the link to the test (for checking my translation <img src="/forums/images/graemlins/smirk.gif" alt="" />)
I wouldn't bet my money on that. Its surface hardness is harder (using Type III Hard Anodizing) then un-heat treated steels, but it is not stronger then steel no matter what the sales man wants you to think.
Anyways I use a Stainless Steel USGI canteen cup for cooking, which is referring to boiling water to get ready to go meals ready to eat (ie meals such as Mountain House meals). Not really "cooking" persay.
Been thinking about getting a Jet Boil though, but I doubt that counts as Light weight. <img src="/forums/images/graemlins/tongue.gif" alt="" />
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