Using the Clean Cycle on the stove

[Paul Beer]

Well, How does everybody feel about cleaning your cast iron in the electric stove on the clean cycle...I have been doing it for several years and have had great results...I have not noticed any harm to the iron such as warping etc and it sure gets it clean in about 2 hours plus a little cooling down time...I have used it on aluminum also with good results...I know there are bound to be some other opinions on this and would like to hear them...Paul

[tjzebra]

hi paul,
as far as using high heat to clean rust or grime , I have no doubt that it works well , but in doing so you are making your products more and more brittle each time, granted it might take a while for any major problems to arise from doing so. like how hot your stove act gets each time.  but anealing metals without proper control of the process , just isnt worth it when it comes to my finds. as far as the aluminium I would suggest that you not engage in that activity any more, depending on the purity of the cast alum your heating up , a very certian and very toxic varity of gases come into play, Ive personally been in the welding fitting industry for the last 30 years and have seen alot of fellow workers getting sick just using a regular stove to heat treat thier aluminium . and that was norm only 400-500f , so if your cleaning cycle is hotter watch out. :) :) :) :)

[Paul Beer]

Michael, Thanks for the information that 's just the kind of expertise I was looking for...I figured there may be some catch in the process...for sure on the aluminum...thanks again...

[Steve_Stephens]

hi paul,
as far as using high heat to clean rust or grime , I have no doubt that it works well , but in doing so you are making your products more and more brittle each time, granted it might take a while for any major problems to arise from doing so. like how hot your stove act gets each time.  but anealing metals without proper control of the process , just isnt worth it when it comes to my finds. as far as the aluminium I would suggest that you not engage in that activity any more, depending on the purity of the cast alum your heating up , a very certian and very toxic varity of gases come into play, Ive personally been in the welding fitting industry for the last 30 years and have seen alot of fellow workers getting sick just using a regular stove to heat treat thier aluminium . and that was norm only 400-500f , so if your cleaning cycle is hotter watch out. :) :) :) :)

This question has been covered several times but deserves to be mentioned again.  I think it is a great way to clean iron with a few exceptions:
1.  No wire handles in the oven as the temper will be lost fromt the wire leaving it soft and bendable.
2.  Don't do a very large load of very heavily crusted pans.  The noxious odors and smoke given off will permeate your house for several days unless you have a SUPER DUTY exhaust fan.  This is from personal experience.
Also, no aluminum in the oven.  I recently recommended that it is ok to do so, but another collector sent me a photo of a skillet cover that was warped, he claimed, by the high temperature (about 900 degrees) during cleaning.  Not worth the risk, although I have done several aluminum pieces with fine results and may do it again.  Also, something was mentioned about taking the temper out of the aluminum if that is possible.  May not be worth taking a chance.

What Michael says should give cause for concern perhaps. But, first, I would want to know more about what he says.  Iron and aluminum cookware and welding practices are not entirely the same.  Does iron really get more brittle each time it is heated?  To 300 degrees?  To 900 degrees?  

Iron cookware is pretty much an element rather than an alloy. Does this make any difference in what Michael says?  I don't know. Iron cookware is made to get hot repeatedly and be cooled.   Wood and coal stoves, grates, etc. are also made of cast iron and get much hotter than 900 degrees.  They also experience corrosion and changes in the metal due to very high heat.  But, at what temp. do the changes and harm happen?  

Does cast aluminum really give off gases when heated?  To what temp.?    Our cast aluminum cookware is supposedly already heat treated.  Does that stop the aluminum from giving off more toxics? In welding, fluxes are sometimes used along with MUCH higher temperatures during welding and I would think that what holds true for welding cannot always be transferred directly to our cookware.  Michael's statements shoud be taken into consideration but I would want to know more specifics before taking them as facts.  Can you add anything Michael?  I'm open to knowing more.   As I understand it, not all aluminum alloys are heat treatable.  I would think aluminum cookware would be pure aluminum but maybe not.  A lot to think about.
Steve

[tjzebra]

steve Ill post a link for you at the end of this speach.
I never was just a welder and the common link between what I was working on , and how it had to be done to pass nuc level tests are all to common to me . as far as cast iron goes you are dealing with a very impure form of metal as far as standards go , it is way hard and if cold enough and thrown hard enough it will break where as most steels will bend, and yes everytime you heat a piece of metal , no matter what it is you have automaticly changed its composition.
I would have gone into finer detail but chances are no one would have understood what I was babbling about.

Now as far as heat ranges and what would be safe , that is all dependent on the manufacturer and the heat number of the batch, whenever a smelter makes a batch of material they assign a heat number to it stating where it was made , its propertys , and when it was made , also  which forge they sold it to. that is why I would find it highly unlikly that you would ever have a piece of pure aluminium used to make a pan . most forged aluminium used to make pas and such are a lower grade with alot of ,, we will say additives . it  is these additives that will end up making you ill from breathing the fumes.

for example have you ever put a aluminium pan on the stove with nothing in it and turned the heat up all the way, or a teflon pan, there is a big dif between cooking something in a pan and just cooking the pan.

I just know that placing my familys health on the line (good fan or not ) isnt worth getting the aluminium pan clean.


http://www.efunda.com/processes/heat_treat/hardening/direct.cfm

[Paul Beer]

Michael, Thanks for the very insightful report...I understand about heating and cooling metal as a factor of fatigue and as I understand it the factors are the frequency of heating,degrees of heating and manner of cooling....I looked in my ovens manual but it does not give the degree used on the cleaning  cycle...It seems people use the figure of 900 degrees but I don't know where that comes from...However, the practical side is how much does it really harm the iron when done only a few times during its life time...The way I use the process is to clean the items when I first receive them and then season and keep em clean from then on...Most of my iron is camp ovens and I know we get some high on those ocassionaly when  doing some pit cooking....I have heard of some guys cleaning these ovens in the fire...and that some have cracked as a result...of course I don't know how long they have left them in the coals but I can tell you a mesquite fire can generate some awsome heat...I never thought that was a smart thing...however I figured the stove option was more controlled and has seemed to work....I use the lowest time the cycle will allow which is two hours and it seems to work on even the real crusted ones...

     I would appreciate any  references or comments you could give on the cast iron process as used in the cookware business....It appears that the quality of the iron has decreased substantially and that we are now getting recycled materials that make heavier and coarser cookware....just look at the new ovens Lodge puts out...they are a disgrace compared to the older stuff...Anyway, thanks again and I would be happy to hear any details you would give...Paul

[Paul Beer]

Michael, PS: Also looking for info on repairing cast iron...see another topic above Paul

[Steve_Stephens]

Michael,
That's an interesting link you gave and I took a look at it.  Having an engineering degree (but did not work as an engineer for long) I can understand what they are talking about though not too well.  

I am not trying to doubt what you say about iron and aluminum but only suggesting that the CAST iron and aluminum may behave in a different manner than rolled, forged (etc.) STEELS and aluminum.

From the link you gave:
"Hardening: Hardening of steels is done to increase the strength and wear properties. One of the pre-requisites for hardening is sufficient carbon and alloy content."

This is dealing with the hardening of STEELS of which cast iron is not.  While cast iron does have carbon content, it probably does not have alloying metals in it-at least the good old stuff.

I also quote from the link:
"Hardness is a function of the Carbon content of the steel....When suddenly quenched, the Martensite is formed. This is a very strong and brittle structure. When slowly quenched it would form Austenite and Pearlite which is a partly hard and partly soft structure. When the cooling rate is extremely slow then it would be mostly Pearlite which is extremely soft."

Cleaning in a self-cleaning oven would seem to follow the last sentence, above (When the cooling rate is extremely slow then it would be mostly Pearlite which is extremely soft).  Also, our cast iron is not QUENCHED but allowed to cool relatively slowing in the mold until solid and, then, in the air naturally.

If that is the case it seems that the iron would remain SOFT.  But your link is talking about STEEL so may not be applicable to iron or, maybe, the aluminum that our pots were made out of.  

All I am saying is that maybe more information is needed before stating what you have said as being a FACT.   You do seem to know a whole lot more on the subject than I do but I question whether you are applying it correctly.  I am a curious person and do not usually take as fact someone's statement unless it either makes complete sense or I get the same facts from several sources.

I do know one thing, though, and that is if you overheat the wire bail handles on our cookware, it becomes very soft and will bend easily.  That is why I say to never put wire in a self cleaning oven nor in a fire.  Does all what I am saying here make sense or have I taken liberties with my thinking?  Just looking for the facts but I really need convincing at times.  Thanks for your input.
Steve

[Paul Beer]

Steve and Mike, thanks for all this input as it is exactly what I was looking for...I believe Mike may have a good point on the Aluminum....However, I'm not an engineer just an old trial lawyer that specialized in aviation defense work for 40 years...as a result I spent lots of time with various metal fatigue issues and the examination and use of metalurgists...I know a  couple that may owe me some favors so will try to kick some help from them if I can...I am very unknowledgable about the cast iron process and it's properties other than the general info that it is brittle and conducts heat very well..I know the brittle part from one of my pack horses bucked off his packs that had our dutch ovens in it and by the time we got the wreck stopped we had three busted ovens...and they do break..make a strong man cry! In any event with all of us pushing we may come up with some sustainable opinions...I would sure like to continue the use of the stove because it sure is easier and faster and you don't have to have a barrel of lye hanging around...Thanks again for the interest and  effort...Maybe WAGS could publish a paper as one of it's first offical acts and have Dave Smith put in the KnC? Paul

[Steve_Stephens]

Paul,
If you run your self-cleaning oven frequently would that wear out the oven noticeably sooner than if you weren't cleaning iron in it?  Could be.  Lye is cheaper and not a problem having around if you have a secure and solid container that won't spill it.
Steve

[Paul Beer]

Steve, I hear what you are saying and it sure is a point..up to now I haven't  had that many cleanings but my collecting etc is starting to increase and friends are starting to bring stuff over to clean and season cause their wives won't let them use their kitchen...so either I get off the oven deal and get a bucket of lye or if I stay on the oven deal get me a used one and set it up in the garage for just this purpose...I have never tried the lye method so guess I better give it a go first...
  By the way preliminary research shows that the cleaning cycle temps are from 800 to 1000 degrees...I'm on the trail of a metalurgist and will let you know what I can findout from them...got to be some kinda of a paper or report in their field on cast iron. Paul

[Troy_Hockensmith]

You know this all sounds alot like when I watch Discovery and the reason the titanic sunk. Wasn't it blamed on the composition of the metal in the hull? (I know it hit an iceburg but the amount of damage I mean)