Black residue on cast iron skillet

Hello,
I'm brand new so I hope I am posting correctly- if not- please let me know how to be a good member on my next posts!
I just bought a used cast iron skillet that has lots of black residue that comes off on a towel when I apply oil. I tried to clean it but the residue remains. It was made in Taiwan. Does that make a difference?
Can I  season and use or do I have to go through a process to remove the black stuff before cooking/baking with it.
Thanks so much for any help!
Cheers,
Nancy

I would heat it in the oven, about 200F for 15 minutes, take it out with a mitt and clean it with oil on a towel, using a clean spot as needed.  Then wipe it clean and dry, wiping as much of the oil off as you can and put it into the oven upside down.  Heat for 1 hour at 400 - 500F past the point of smoking.

Read more about seasoning cast iron - http://gnowfglins.com/2010/03/12/how-to-season-cast-iron/

I hope this helps.

Hi Nancy:  Paul is the expert on cast iron around here.  I read his article on cast iron and Ive been finding and cleaning old cast iron around the house all day -- I was so inspired.

He does not mention this method though:

http://www.youtube.com/watch?v=GKYViowWP5w&feature=related

Coca cola - like naval jelly - both contain phosphoric acid which will convert iron rust (iron oxide) to iron phosphate.

Using Paul's instructions Ive found this method works on even really old and crusty cast iron.

Heat the pan -- I am using a gas stove.  Use a low heat but leave the pan on the burner until it is really hot.  After 10 minutes or so use heat proof gloves to remove the pan to a cooling surface.  Put another pan over the flame if you have a lot of them.  After the pan is cool enough to handle use a steel scraper, a steel spatula, a razor blade scraper, dental tools, a wire brush, or wire brush and drill or whatever you like to clean off the cooked rust.

It comes off really easily but it makes a big mess.  Wear safety glasses if you use a wire brush.  Then put the pan back on the flame and pour in about 1 T coarse salt.  Spray a folded paper towel with a spritz of canola oil (or dip in lard or whatever you are using). Scrub the salt over the pan's surface with the oily paper towel.  Wipe the pan down with fresh oil and paper towel until you no longer see black, or until you get tired of doing it.  The heat will sterilize any disgusting stuff that has been in the pan.

Hang the pan up from a pot hanger and keep it handy to use.  Never use soap or soap and water on the pan.  Just rinse out quickly under hot water and repeat the wipe-down with oil and salt after heating the pan, and then hang it back up on a dedicated hook.

Have fun and buy more iron pots!  There is so much iron out there rusting away and it needs a good home!

Well,
wombat, it seems as though the black stuff is part of the pan. I followed the directions twice and although the pan looks clean and down to the metal ( it has concentric rings) the paper towel comes away with quite a bit of the black smudgy stuff. There is no ash, particles of food etc.
It is as though I am actually removing part of the surface.
I wonder if continued tries will result in the towel wiping clean or if it is a lost cause. Could the Taiwan manufacture be a factor?
Is cooking in this pan safe?
Thanks in advance for any suggestions or advice.
Nancy

"it seems as though the black stuff is part of the pan"

It may have a commercial seasoning on it.  I would continue to heat and clean with salt and oil when ever you think of it until you feel like it is safe to cook in.  It probably is food safe now, but you never know.

If you have a self cleaning oven, or know someone who does that will remove the seasoning.

There is more discussion here:

https://permies.com/permaculture-forums/3385_0/cooking-and-food-preservation/cast-iron-polymerizing-oils-and-a-better-seasoning

Also Paul has written on cast iron pans -- see the Articles.

Good luck.

Thanks again! I really appreciate your posts to help me.
I guess there are only two options- stick with it or get a different pan.I'll keep trying with this one for a while to see if the heat and salt/oil combo will work. Next time I have something  to bake for an hour, I'll just throw it in the oven as well.
I wonder if the pan ended up at the thrift store because the previous owner had the same problem. There is no manufacturer to call as the pan is stamped only with Taiwan. Sigh.
Cheers,
Nancy

Wombat - I so appreciate your experience and input added to this conversation.  I'm sure you know that Paul is not territorial about this forum, and whole hearty welcomes EVERYONEs input and perspective.
I was not stealing Paul's thunder, Paul is a big boy and can jump in on any discussion he chooses, adding his experience.  A discussion is all the better for all the participants, links and perspectives.

Nancybc - I did a search on your specific problem and found others in your boat, seems it is a pre-seasoning of sorts.  Others with this issued also used steal wool,  as was suggested on that link I gave you.  I have found that to be successful with regard to the back-stuff on pans I bought from a discount store.  The entire method I use of oil, heat and steal wool is explained in the link.

Also, another suggested I have found (but have not use myself) is to use oven cleaner in the usual way to remove everything and then clean your pan good and start a fresh seasoning.  I'm just throwing this out in case nothing else works for you.

I also found this in my search for your situation -

ATTENTION - PLEASE READ:

All new cast-iron pots and skillets have a protective coating on them which must be removed. American companies use a special food-safe wax; imports are covered with a water-soluble shellac. In either case, scrub the item with a scouring pad, using soap and the hottest tap water you can stand.

You may want to try your own search to see what other information you might find.

Best of luck to you,

~Jami

Thanks Jami,
I have used the steel wool but not the oven cleaner. I'll give it another go. My concern was that the residue was actually something in the metal that would leech into any food cooked in it.
Thanks for the research. Who would have thought that buying a used skillet would lead me to a new forum, helpful people and in depth information on all things cast iron.
Ain't life grand-lol!
Cheers,
Nancy

http://www.richsoil.com/cast-iron.jsp

Jami McBride:  I was refering to Paul's article on using cast iron.

Yes, Paul's article is very helpful.  He really figured some cool stuff out with cast iron.  We also have a thread here which discusses his article and covers even more information -

https://permies.com/permaculture-forums/3385_0/cooking-and-food-preservation/cast-iron-polymerizing-oils-and-a-better-seasoning

you could try to put water and even some soap in it and boil it good,

I have cleaned up old cast  iron with alternating baths of lye and hydrochloric acid,

the only other thing is if some one used it for some thing other than food preparation,
being made overseas I would not think it should make a difference.

if you know of some one with a sandblaster  or a glove box medium blaster, that is an option as well, blast it clean to metal and then season it,

Thanks Jami, wombat and birdman.
I'm almost ready to give up! I used oven cleaner applications 4 times today and steel wooled in between each application. The pan looks like it is down to the base metal- but- a damp paper  towel still wipes up some brownish residue. A lot less- but there none the less. I am assuming that a clean pan should not still have brown stuff coming away from the surface. It's not rust and not visible. Dry cloth comes away clean.
I  could try boiling but sand blasting is above my pay grrade-lol.
I really am beginning to think that the pan may not be fit for cooking food.
Thanks again for all the help!
Nancy

nancybc wrote:

I am assuming that a clean pan should not still have brown stuff coming away from the surface. It's not rust and not visible. Dry cloth comes away clean.

I would say it's good enough, your done!   I don't know that any cast iron pan I've had has passed the wipe test.  Once you have a good season/seal on it all will be well.

Shout out if you have any other questions....

All you need to clean any cast iron cooking utensil is heat, coarse salt, and oil with a high smoking point -- see the chart in the other thread.  And some scrapers such as a stainless steel  spatula.

You can use a sand blaster, or soak in water and detergent, etc. etc. etc. but you are just making the pan harder to clean.

The heat oxidizes rust and grease so that it is released from the iron surface, it also sterilizes the pan.  All you need to do after heating is scrape away the rust and old grease.  Salt absorbs the old grease, and the oil cleans up the gunk and provides a new seasoned surface.

Yesterday I cleaned some 30 old iron pans, some of which I found in the attic and have not been used since 1930.  This is the method I used and all of them are now ready for cooking.

water will make the pan rust, soap is redundant to heat on iron, oven cleaner is noxious and could leave carcinogens in the iron.

as far as having some residue on the bottom of the pan for normal use I agree,

but IF I get used cast I like to take it down to  raw steel and start in again unless I knew the history of it, 

as on my cast iron, in the barn, (yes I have a small complete kitchen in the barn) many of the times the clean up consists of a very good scrapes with a spatula  or  some hot water and a swirl with a stainless steel scrub pad,  and yes you could take a paper towel and  alway get some residue off of it,  (many times I just put the lid on and leave it on the stove for the next time with the oils of the last cooking in it)

In the house kitchen my wife is much more aggressive in the cleaning process, (many would say she does not clean the Cast correctly but over cleans it, as it is basically down to cast iron no real sign of seasoning on the inside of the skillet, but there are the oils in the pores of the cast and it  and on some of it one can rub a paper towel on it and get a little marking on the towel,  (most not), but if you follow the suggested cleaning of cast she over cleans it,

the cooked on oil build up  is what the seasoning is,  and that what makes the natural non stick surface,  is in a sense that it has a cooked on oil coating  (or really simple a dirty pan), that makes part of cast iron what it is,
so some residue in the bottom of the pan I my opinion would be perfectly normal, and should be expected if properly seasoned and used,,

The inside of my hand me down iron skillet is beautifully seasoned but the outside is crusty i mean layers of crust how can i clean without damaging the wonderful pan interior...nataline the happy hand me down recipient

Using my definitions, you have to work very hard to damage a cast iron pan ....although i managed to do it once.  I would turn it upside down and use a wire brush on it. You can rinse off the outside with water. But do not submerge it in soapy water.