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CarolinaJP
08-24-2008, 20:17
I've heard that stainless steel pots when cooked with long enough become "tempered." Do we agree that this discoloration/tempered cooks better than new stainless steel? I've yet to achieve this look with my old MSR pots but Im thinking of throwing them in a fire and letting them roast for a while (not the inside!). In other words tempered is to stainless as patina is to copper, loosley based analogy. What do yall know about this? I'll probably use some apple wood. I know I could search for this but I enjoy getting the feedback and it leaves my question open for other ideas.

mudcap
08-24-2008, 21:11
NOT TRUE at all. Simple,you will ruin the integrity of the steel. SS,gains nothing from this process. Carbon steel does,if a certain steel has been hardened,it needs to be tempered to bring back the elasticity. I am talking about cutting edges. Cooking pots,no way they gain from this idea. Heat treating is simple and sometimes complex. Tools are of concern,never cookware. That being said,seasoning cast iron cookware,that is another deal. Oil and heat....

mudcap
08-24-2008, 21:19
NOT TRUE at all. Simple,you will ruin the integrity of the steel. SS,gains nothing from this process. Carbon steel does,if a certain steel has been hardened,it needs to be tempered to bring back the elasticity. I am talking about cutting edges. Cooking pots,no way they gain from this idea. Heat treating is simple and sometimes complex. Tools are of concern,never cookware. That being said,seasoning cast iron cookware,that is another deal. Oil and heat....

Hope that made sense.

Bob S
08-24-2008, 21:39
I have a Coleman Peak 1 stainless steel cook set, it’s at least 20-years old and it is discolored some, not a lot. But as far as I can tell it cooks the same as it always has. I would not want to take a chance of destroying it for a mythical few seconds less of cooking time.

GGS2
08-24-2008, 22:21
I've heard that stainless steel pots when cooked with long enough become "tempered." Do we agree that this discoloration/tempered cooks better than new stainless steel? I've yet to achieve this look with my old MSR pots but Im thinking of throwing them in a fire and letting them roast for a while (not the inside!). In other words tempered is to stainless as patina is to copper, loosley based analogy. What do yall know about this? I'll probably use some apple wood. I know I could search for this but I enjoy getting the feedback and it leaves my question open for other ideas.

Folk tales. The discoloration (blue, yellow and so on) is merely superficial oxidation to various depths. Stainless steel is "stainless" because the mix of alloying metals (chiefly iron, chromium and nickel) causes the metal to form a conformal coating, very thin, of oxide on the surface. which then resists further oxidation, ie., rusting. Heating in the presence of oxygen and or carbon may disrupt this coating, alter the metal to some depth by addition of carbon or by increasing the surface oxidation depth, which will usually color the surface more or less permanently by a couple of processes, including carburization and interference colours owing to deep transparent oxide layers. Under certain circumstance, a nitride coating may also be formed.

None of these processes is tempering. Tempering is a carbon steel process which is intended to improve the malleability or ductility of a hardened carbon steel by altering the carbon chemistry of the steel. Carbon steel with more than about a tenth of a percent of carbon may be hardened by heating to above the solution temperature, the temperature at which carbon dissolves on iron, and then quenching in cold air, water or oil. The quenching freezes the carbon in the iron solution so that it forms a metastable compound called iron carbide, martensite or stellite. Metallic carbides like this are very hard, like the silicon carbide used to make grinding wheels, or other carbides used to make machine tool cutters. Iron carbides were the first carbides used, in the form of solution hardened carbon steels. This structure is found in metals such as swords and gun barrels of the later iron age. These early steels were useable because the brittle carbides were sandwiched in a multi-layer structure with ductile iron. This made a tough blade or gun barrel which was also capable of being formed while taking a keen edge, or forming a stronger structure than simple iron. Damask steels are of this type, as are Japanese sword steels.

When control of the carbon content of the iron became feasible in the late iron age, it was found that high carbon steels were too brittle for many uses, although they were very strong, could take a keen edge and were harder than any metal then known. The ancient metallurgists knew that to make a sword, for instance, tough as well as sharp, it was necessary to heat the hardened metal to a lesser temperature than the quenching temperature, and then cool it more slowly, in a controlled way. This "tempering" allowed some of the carbon to come out of solution, and also altered the grain structure of the crystals of iron carbide, which gave back to the tempered structure some of its iron-like properties of toughness, while retaining some of its hardness. There are many techniques of tempering which selectively harden and toughen a steel part where these properties are required.

A cooking pot made of thin stainless steel requires none of these processes, nor does it benefit in any way from the discoloration of surface carburization/oxidation. On the other hand, it is not much harmed by it either; at least not normally. If there is a flaw in the metal, or a particularly savage heat deformation, then the surface may lose its stainless quality and begin to rust. This may result in pitting and possibly perforation after some time.

Stainless steel cookware is not carbon steel. It is usually some alloy similar to the original stainless alloy, so-called 18-8 stainless. This alloy is not heat treatable. Burning in a fire may add a small amout of carbon to its surface, but this will have almost no effect on the bulk properties of the steel, and may harm the stainless quality of the steel. Ordinary wood or gas flame discoloration is unlikely to be too harmful, but heating in a campfire in order to "temper" it will do nothing good to the pot, and may shorten its useful life.

CarolinaJP
08-24-2008, 22:51
We'll we solved that one. Thanks! My intentions were not really to reduce cook time but to relive my problem of scorching my food. I use a pocket rocket and despite my great cooking abilities I often burn my food. I can't get all of the oil the same temp. It's popping out in the middle and not hot enough around the outer circumfrence of the pot. I rarely use these pots, only when I have more than 4 people eating so this is the only pot I have trouble with. Thanks again and GGS2 you really brought it.

GGS2
08-25-2008, 00:57
Carolina JP, this is a common problem with stainless steel camp pots. It is caused by about three separate properties of the system:

1. Concentrated, very hot gas flame on the center of the pot bottom.
2. Thin pot material (to save weight).
3. Poor conductivity of the stainless steel compared to copper or aluminum.

The thin pot and poor conductivity prevent the concentrated heat of the flame from being spread over the pot bottom effectively. So, you get a hot spot in the middle. Solution: spread the flame somehow so it hits more of the pot bottom, and lower the flame temperature where it hits the pot, or use a temperature spreading pad under the pot. A thickish aluminum plate between the pot and the flame would work. Also an asbestos or ceramic fabric pad: both of these have adverse health implications, so they are NOT recommended. See how thin an aluminum plate will work for you. It will probably end up being less than an ounce.

If your stove has an adjustable flame, try turning it down some.

An additional benefit of the separate heat spreader plate will be that your stainless pot will stay bright and shiny. The plate may not need to be as big as the pot diameter: the idea is to spread the flame heat away from the hot spot. It may be enough to insert a round of aluminum from a can lid or a roaster pan about twice as big as the discolored spot on your pot, but make sure it is centered over the flame for best effect. However, if the flame from your stove is full blast, a thin plate like that might not survive. In that case, make it thicker and wider. Or try a steel can lid instead of the aluminum. Steel is a poorer heat conductor, but it will survive a much higher flame temperature.

A small alcohol burner will be less likely to overheat such a system. Flame is less intense and easier to spread.

All the best.

Peaks
08-25-2008, 06:45
We have used the same Revere cookware for decades at home, and have no intention of changing. It's copper clad bottom over stainless steel.

NICKTHEGREEK
08-25-2008, 07:37
I've heard that stainless steel pots when cooked with long enough become "tempered." Do we agree that this discoloration/tempered cooks better than new stainless steel? I've yet to achieve this look with my old MSR pots but Im thinking of throwing them in a fire and letting them roast for a while (not the inside!). In other words tempered is to stainless as patina is to copper, loosley based analogy. What do yall know about this? I'll probably use some apple wood. I know I could search for this but I enjoy getting the feedback and it leaves my question open for other ideas.
I think you really need to find something to do.

weary
08-25-2008, 09:16
We'll we solved that one. Thanks! My intentions were not really to reduce cook time but to relive my problem of scorching my food. ....
That's my technique. All my pots of whatever composition have been burned on at one time or other. It seems pretty harmless -- except for getting the burned food off.

Weary

Bob S
08-25-2008, 09:27
That's my technique. All my pots of whatever composition have been burned on at one time or other. It seems pretty harmless -- except for getting the burned food off.

Weary

Oven cleaner works great on stainless steel to clean it up. Not good for aluminum as it eats it and copper.

CarolinaJP
08-25-2008, 14:14
Nick the Greek Im preparing for a long hike. Elders are usually cool people cause they been around so long, I just don't know what happened with you.

weary
08-25-2008, 18:00
Nick the Greek Im preparing for a long hike. Elders are usually cool people cause they been around so long, I just don't know what happened with you.
Well, Nick The Greek isn't really an "elder." Us old folks are living longer these days. Just today, the obit page of our local paper reported one person older than me as having died.

Of course there were another seven or so younger than me. But I remain optimistic. One guy who died, however, was a bit worrisome. He was just three weeks older than me. We had both worked illegally at ages 13 for a Chicago company that was processing a sea weed on a beach in my town for creating a syrup for a chocolate milk drink.

WE were never close friends. But I always admired him. He had quit school at the end of the eighth grade. I managed a belated BS (bachelor of science) at the University of Illinois, but he founded and ran a number of businesses and I'm sure earned over his lifetime several times more than I did.

Weary