Heather says:
I’ve used the All-Clad Emerilware line for years (7), I love my cookware. I’ve slowly been supplementing the basic set with a few choice vanity pieces here and there. I think it’s a great set for aspiring cook and so I gave my sister and her husband an identical set as a wedding present.
Something strange happened though, I stopped by to see her at work one day and she told me this bizarre story of how one of her pans had melted, the bottom plate fell off and the liquid metal damaged her floor.
This made no sense to me. If it were a gas range, I suppose, if the pot had boiled dry it would be possible for this to occur. However, it was a standard (non-inductive) smooth top electric range. These have thermostat (there’s a more accurate term for this, but I don’t know it offhand) that shut the burners on and off as they reach the appropriate temperature. Even at the highest setting, this is nowhere near the melting point of the aluminum core (1220F if you need to know) of the stainless steel set. So what happened?
My husband who is an electrical engineer in the steel industry, finally figured out a potential reason for this freak occurrence. I’ll share his reason and then translate it from engineer1 to English.
His:
The basic premise of electric range operation is to pass current through a resistive conductor thereby transforming electrical energy to heat energy. Another effect produced by this is a rapidly expanding and collapsing magnetic field. This is the source of the magnetic lines of flux, which interact with the non-ferrous metal layer in the pan through the Lorenz effect, to produce Eddy Currents (Note: You may be thinking that Hysteresis losses would play a big part in this, but you’d be wrong). It may be this centralized inductive build up of heat due to the excessive eddy currents in the aluminium layer that is causing temperaturess to exceed 1220 degrees fahrenheit and the eventual catostrophic failure of the cooking vessel.
My version:
Aluminum is a nonferrous metal, meaning it cannot interact with magnets, but it can conduct a current, this current can create a magnetic field and sometimes the electric current in the burner can create a magnetic field. And once in a while these magnetic fields can interact. Have you seen the newer ranges that use magnetic induction to heat pots while the surface of the range stays cool? This freak accident happened due to the same principle, only it happened in an uncontrolled way causing the temperature to surpass the melting point of the aluminum.
*If you’ve been with me through the edits, just hang tight, I’ll get it right one of these times. I can see it in my head, it’s just refusing to come out in a semi-articulate manner.*
Thankfully no one was hurt. As this is just a freak, unintended interaction between the burner and the core of the pan, I don’t know that it could have been prevented.
I use these pots and pans every day, but I am a little more careful about letting the kids wander underfoot in the kitchen.
1 Why yes, we are fun at parties, why do you ask?
Wow. I guess I need to be more careful, as I didn't know this could happen on a glass top range, which I have. Hmm. Is it weird that I pretty much understood what your husband said?
It could happen on any electric burner. It's the creation of the magnetic field with the flow of electricity that triggered the failure. For a long time I had figured it was a defect in the pan, but really an electric burner should never get anywhere NEAR hot enough on its own to melt, even a defective alloy.
*I* don't think it's weird, but I may not be the best judge.
If you don't watch it already, I highly recommend The Big Bang Theory.
It's at the top of my list on Mondays.
wowza
^^^ The Big Bang Theory Rocks.
Hey Heather, you might consider rewording the first sentence in your translation. It makes it sound like non-ferrous metals are the ones that interact with the magnets most people are familiar with, when it fact it's opposite. Thus, the term "ferromagnetism".
With that random bit of whatever, I go back to cleaning my damn house. <3
(PS. My mother has a new induction range. It's weird and freakish, and if I didn't know the science behind it it would be scary-magical and I'd only be able to be in the same room with it if holding a crucifix, a stake, and silver bullets.)
(PPS The cleaning might be doing my head in.)
I garbled my part completely, that's what I get for waiting a week. I meant to say that it cannot interact with a magnet, but it can create a current that creates a magnetic field with the steel.
Anyhow, short part of the story is that it's the interaction between the conductive metal, the magnetic field and the burner creating a harmonization.
You'd think you were all overwhelmed with words with writing a book, or something.
(Um, "turning this current can create a magnetic field. Sometimes the electric current in the burner can create a magnetic field" is, uh, interesting. One more time?)
Maybe you can bring up harmonization/harmonic frequency in terms of the Tacoma Narrows bridge? Is that too dorky? Although it was actually caused by aerostatic flutter, it gets the point across about amplification by resonance.
(back to cleaning again. I'm vacuuming lampshades.)
You know, thank goodness for editing.
I swear these next 9 days are going to kill me. I’m looking forward to Saturday immensely, if only to not have to think of my own words for a few hours.
I am too. If only because it might actually be the *most* relaxing day of my last few weeks.
Not to pile on, but we should decide on t-shirt words. </slightlycryptic>
Even instead of Real and keep the man.
/just as cryptic
The blonde eagle flies at midnight.
</now just being silly>
My favorite sentence: "Note: You may be thinking that Hysteresis losses would play a big part in this, but you’d be wrong."
I stand corrected
This is interesting, as I'd never heard of such a phenomenon before.
http://www.consumeraffairs.com/homeowners/emeril_…
One of the consumer entries: "Lisa of Woodbridge, VA April 21, 2009
Emerilware with All-Clad Metalcrafters. Had two separate stock pots explode from the bottom spewing molten aluminum. The first must have occurred when in use by a family member. I didn't find it until I went looking after the second. The second occurred just shortly after I put a pot with water onto boil. I was standing right next to it when it occurred, first a popping, smoke, and molten aluminum on my range and my clothes. Fortunately, I was not burned. However, my family or my pets could have been potentionally harmed had anyone been standing next to me. The burner on the electric range. The bottom of the pot reflected an explosion. The burner reflected an implosion.
All-Clad denied any defect in the product line and blamed it on my range burner…what about the folks who have gas or smoothtop? This product poses an extreme danger to anyone using it. Time is not on your side, folks. STOP USING IT. I loathe having to destroy a gorgeous set of cookware I had owned for just a few months, but I won't take the risk and even donate it. I plan to destroy them. By the way, All-Clad kept the damaged cookware…never returned it, but I have pictures! I urge everyone who has had these problems to contact the US Consumer Product Safety Commission and lodge a Consumer Product Incident Report. This cookware MUST be removed from the market. Out the cost of the cookware, some 250 and destroyed the burner and the plug-in unit, which will run close to 100 to repair on my own, more if I contract out the repair.
Read more: http://www.consumeraffairs.com/homeowners/emeril_…
The phenomenon I described would be limited to electric ranges.
My physicist hubby loves to melt things. He builds kilns from scratch, uses vacuum cleaners or old hair dryers to add oxygen, various torches, etc. Thank goodness I don't have any of these pots or he would be trying to do it on the oven.
I'm curious about the metal content. It is stainless steel with an aluminum core?
Yes, these pans have a stainless top and bottom, an aluminum disc and there is a copper band around the outside.
this happened to me two days ago. with a cuisinart stainless steel pot.. it burned a large hole into my sneaker, and sent liquid aluminum across my kitchen floor. I have holes burned into the linoleum across a large area. Usually my 19 month old is directly underfoot. Usually I am barfoot in the house.
I contacted the company the next morning. Called them back with the model # of the pot. The customer service rep said she had never heard of this happening. But would not discuss the claim with me, stating that it was too serious in nature and is turning it over to corporate. I am looking for a product liability lawyer. They have indicated that they would take care of damages. I am outraged that this is something that can happen, has happened, and yet there are no warnings.
The pot was on the burner no more than 5 minutes. the bottom didn’t even burn out and get blackened. It is a bright cobalt blue! I have never…. I have quite of bit of money invested in this cookware. I have a few caphalon pieces, so i opted to use as much of that as possible this evening, but had to use some of the cuisinart. talk about anxiety. I purchased a gate to keep the baby out of the kitchen while cooking. Paranoid as I was next to the stove..
It will be interesting to see how this plays out. Companies are responsible to make consumers aware of such occurances, no matter how infrequent they may be. Any other day, my baby would be in ICU with catastrophic burns, and in my panic, I would not have had as much control of that pot and would have sustained substantial injuries..
One more occurence of this today at my place. Same context: electric stove and Emeryl pot.
The liquid metal flew all over the place, the kitchen is now full of burn spots, but nobody got injured.
Great information here. Our adventure tonight was all the same but with a 38 year old Farberware pot! So the brand may not be the issue.