rust color... what does it mean

[Lewis Downey]

Hello,

I have read a few posts suggesting that bright orange rust is a telltale sign of a fakes/repro. That's a head-scratcher for me.

I thought there is more or less general agreement that iron is iron. Why would the color the of the rust suggest a fake? 

What else can be learned from rust color?

Thanks!

[Cheryl Watson]

Lewis, check the most recent issues of the Casting Call Available in the .pdf section.  Vol 10, N3 has a large article on the subject. :)

[Lewis Downey]

Cheryl, thanks for that info. I read the article a couple of times and will study it more to clarify my understanding of what takes place in the electro.

I didn't see anything in the article could be extrapolated to explain why fakes/repros would have different colored rust from original manufacturers.  Is rust color a wives tale, so-to-speak, amongst cast iron collectors seeking to identify fakes?


edited to add an example - perhaps a little bit out of context

You have to learn to recognize the metal. The old Iron has a different look because of its metals content.  (Nuther Charlee note:  Old iron will rust "brown" (think rusty old bridge) while newer iron will have the more orange rust.)

Suppose you had a skillet that was cast several decades ago but only rusted recently; is it the case that the old iron will never rust bright orange? If so is there a cutoff - like I dunno 1970 -> iron newer than 1970 will rust bright orange but iron older than 1970 will only rust brown?  <not suggesting 1970 as a meaningful date only using it as an example>

I'm not trying to be difficult only asking the question because it seems counter intuitive that rust color would be a good predictor of fakeness. Pardon me for running on with the obvious questions  but did people only start making fakes recently? If not will an old fake iron rust orange instead of brown?

If some fakes could have brown rust and some old legit iron could have orange rust (if that is the case) then how can rust color be a reliable indicator of whether a piece is a repro or not.  Is it any indicator at all?

Thanks again!

[Mark Zizzi]

Hi Lewis, This is an interesting concept, but in my opinion..rust is rust. Doesn't matter the age. Possibly, a newer cast piece could rust more severely, which could make it redder in color maybe,  due to less "seasoning protection". But I don't think it's something that necessarily defines an authentic piece from a repro. A possible red flag maybe, but not the only thing you need to look at. Again, this is just my opinion..if someone has a different opinion, I'm all ears too.

[Cheryl Watson]

I look at color variations as an indicator of the age of the RUST itself rather than the age of the object that is oxidizing.

New Rust appears more ORANGE in color,,,, old established Rust is darker, and may indicate more penetration into the metal (iron).

Does that make sense???

[Lewis Downey]

Mark, thank you for your thoughts.

Cheryl, yes that makes perfect sense! It is how I look at rust too. My head-scratching is over the suspicion some people have that bright orange rust is a warning sign for fakes. Based in part on your comments, I'm going to disregard rust color when trying to determine if a piece is a fake or the real McCoy -- unless someone can help me see the bright orange light. :)

Does rust color suggest amount of damage

If the rust is orange rather than brown does it suggest the possibility of minimal damage to the iron  -- since the rust is younger and has had less time to attack? Does brown rust suggests the likelihood of more damage, since it has had more time to do damage?

More rust questions

• Is one of these patterns more common
• brown rust on top of orange
• orange rust on top of brown
• Is one of these dependably worse than the other
  • thin layer of brown rust
  • thick layer of orange rust
• Is there anything else to take from rust color?

[It turns out a lot of the iron I am buying has rust :)]

[Jim Glatthaar]

Cheryl, your explanation makes perfect sense to me.  I can even back it up with some anecdotal evidence.

Last year, we went away on a two week vacation.  We have herbs growing in a greenhouse window in our kitchen.  I water the herbs by placing them in the sink and when the water has run though, putting them back. 

Our pet sitter didn't figure this out.  Instead, they went looking for an object to place the herbs in so they could water the herbs in place.  And they found it: a #9 Erie, second series.   :o  When we arrived back home and saw the creative watering tray, I noted the skillet had large bright orange steaks through it.

It's a good thing our dogs love our pet sitter.

In any event, I stripped and reseasoned the skillet ... and bought some trays for the herbs.  This is a wordy way of saying, I think you're right.

[Tom Neitzel]

I like Cheryl's suggestion too. 

[Sandy Glenn]

ve read a few posts suggesting that bright orange rust is a telltale sign of a fakes/repro.

My head-scratching is over the suspicion some people have that bright orange rust is a warning sign for fakes.

I'm curious, Lewis, where did you read this?  I've never heard of anything so far-fetched.  It sounds like something that would spread like wildfire around facebook.

[Lewis Downey]

Hi Sandy,

Maybe I am mistaken but I think I have bumped into it at least a few times on WAGS. This is my primary information resource for cast iron, but sometimes I consult other sources too. Maybe I am misremembering where I saw the references. When I can find a little time to poke around, I'll try to find examples.

Generally the posts went like this. Someone commented on identifying or perhaps mistakenly buying a fake/repro. They would then list attributes which were clues to the fact that the piece was not original. It surprised me to see "bright red rust" or something similar listed along with poor casting quality, smaller size, faint engraving, etc.

Thanks for the question. I'll post an update after some research.

[Lewis Downey]

I think I have bumped into it at least a few times on WAGS.

Sandy, I can't find it anywhere on this forum. There seems to be a problem with the database... the one in my head, not the one holding these posts.

It wasn't hard to find references in other places though.
[list bull-redball]

• http://www.antiquetrader.com/antiques/how-to-avoid-fake-griswold-and-wagner-cast-iron-antiques (several times throughout the article)
• http://www.treasurenet.com/forums/garage-sale-finds/421258-griswold-repro.html
• a comments on reddit suggest widespread acceptance of the idea
  
  

  Be wary of poor reproductions which can rust easily and turn orange though. Source: My stepdad collects Griswold cast irons and has a tower of them of various sizes in his basement.

  
   

  Obviously all iron will rust. The carbon content of the new cast iron is different from the carbon content of the old. The difference in carbon produces a red rust on new cast iron. Rust on old cast iron is a dark brown or brown/black. -Any website warning you about Griswold/cast iron fakes.

Well done for WAGS though! I searched the forum pretty thoroughly and other than this thread couldn't find a meaningful reference to the notion of red rust suggesting fakes.

[Sandy Glenn]

Lewis, Thank you for citing your sources (always a good idea).  I noticed the treasurenet link cites as its source the same antique trader link you originally cited.

Please remember what you read on the internet (including this site) is almost always somebody's opinion.  Sometimes it can be confirmed or substantiated and sometimes not.  In other words, don't believe everything you read.

IMHO the color of rust has absolutely NO bearing on the authenticity of a piece of iron.  There are much easier and truer methods to determine if a piece of iron is authentic or a repro/fake.  That's why we have this section on this site that's available to everyone:

http://www.griswoldandwagner.com/information/Repros/repros.html

[Claudia Killebrew]

Just a thought here, since I have no true knowledge of the how's and why's of rust, aside from iron+wet=rust.

It seems that yes, the composition of the iron could have an impact on the color of the rust, but could the composition of the water also have an impact? That is, would rain water cause a different color than tap water? Especially if the rain water is high in acids? What about steam? Or in Jim's case with the plant run off, would the soil content also have an influence?

[Jeff Friend]

Would you believe someone that said they could tell if a dog was aggressive or timid by the color of its coat?  I wouldn’t and I doubt you would either.  So, after doing a little reading, here is my two cents on the topic . . .

Grey iron is a mixture (alloy) of primarily iron, with carbon, silicon, phosphorus, manganese, and sulfur.  These elements are present in small amounts (a few percent) to traces (a few hundredths of a percent).  These ratios probably have not changed significantly over the past century or more.  I would expect that there was enough variability in the composition of iron in the 1860s – 1920s that today’s grey iron (what Lodge uses) falls within those ranges.  The carbon content of grey iron was, and still is, in the range of 3 to 4 percent and is composed of graphite flakes.

Iron oxide is iron + oxygen.  The iron exists can exist in the ferrous (Fe++) and ferric (Fe+++) oxidation states:

*  Fe2O3 is hematite.  It is ferric iron.  It is orange-red.
*  Fe3O4 is magnetite.  It has two ferric and one ferrous iron.  It is black
*  FeO is wustite.  It is a non-stoichiometric mixture of 85 - 95 Fe atoms per 100 O atoms.  It is grey.
*  FeO(OH) is iron oxide-hydroxide.  It is ferric iron.  Its color ranges from yellow to brown.

Water molecules are a part of what is generically called rust, and it plays a part in the appearance of rust.  For example, FeO(OH)[ch8729]n(H2O) is Lepidocrocite and is the rust found in water pipes.  Different oxides of iron can also exist together on one rusty specimen.  So, it appears to me that rust on a skillet can exist as a mixture of more than one, and possibly, many different forms.  And this is without the complicating factors like pH and other chemicals, such as sulfate, carbonate, and chlorides, that may be present.

My conclusion is that iron doesn’t rust any differently today than it did 150 years ago.  Oxides of iron exist in different colors or shades of colors.  I would be very skeptical of anyone that said they could date a pan by looking at the rust.  The variations of rust we see in hollowware are primarily a function of the environmental conditions that caused the metal to rust and how long it has been rusting.

As Sandy said, there are better ways to determine what is a reproduction.  Come to a convention and see all of the repro and fake pieces in the WAGS collection for yourself.  You will be much better prepared to identify a fake by actually holding and inspecting known fakes than by reading garbage on the internet.

[Dwayne Henson]

The only differences in the iron might be the trace elements from the geological area the iron ore or pig iron came from. Now would some elements help retard rust? Maybe. Any geological difference should disappear with the event of WWII as all the cookware foundries went to a 100% scrap iron pour, as pig iron was a war essential and was not available for cookware during the war years. Then after the war when pig iron became available again, a scrap/pig iron mix was still used because of the cheaper price. In my mind any rust retarding properties that certain geological areas had would have been eliminated during the war years and then diluted post WWII do to the continued use of scrap as well as pig iron mix. I guess the only way to truly see would be a test. Different foundries skillets, all pre-WWII, left out in the elements with photos taken every few days and see what colors they turn. No I am not volunteering. ::)