"Rust" Spots on Your Forged Cutlery?

[dannyzmom]

Well, for starters it's not rust, it's carbon spots...but that's another discussion.
Just wanted to pass on this tip -- a smidge of Barkeeper's friend & a sponge...a few wipes...abd they're gone! Yippee!

 

[whiteyteresa]

Thanks for the info

I justed noticed spots on mine late Friday night and I was going to call HO and tell them

Thanks

~

 

[vwpamperedchef]

Thank you! I was using my chef's knife today and saw them. Ill have to research carbon spots, because a customer was grilling me about it, and how stainless isnt supposed to rust, etc etc, and I told her I would find out why that happens.

Need to get some bar keepers friend. YAHOO! THANKS

 

[dwyerkim]

I've notice a spot here and there too... do you know what causes them or how to prevent them in the first place?

 

[krzymomof4]

Thanks Carolyn. I just had a customer email me and ask me if it was normal. So....get into the discussion; what are carbon spots. Just for future reference of course.

 

[dannyzmom]

Thanks Carolyn. I just had a customer email me and ask me if it was normal. So....get into the discussion; what are carbon spots. Just for future reference of course.

That's a question for Ann, queen of endless information

 

[chefann]

Thank you! I was using my chef's knife today and saw them. Ill have to research carbon spots, because a customer was grilling me about it, and how stainless isnt supposed to rust, etc etc, and I told her I would find out why that happens.

Need to get some bar keepers friend. YAHOO! THANKS

That's true, but our forged knives AREN'T stainless steel, they're carbon steel. Stainless is good for an environment that's likely to be hard on keeping things clean and dry. But stainless knives don't hold an edge as well as carbon steel.

In fact, this is what Alton Brown has to say about knives in Gear for Your Kitchen:

Most kitchen knives are made of either carbon steel, high-carbon stainless steel alloys, or regular old stainless steel. SS knives are widely available but impossible to sharpen, and quality knifesmiths never mess with the stuff unless they're making pocketknives, so we'll discuss only the first two materials here.
Steel is an alloy containing some 80 percent iron and 20 percent other elements. In carbon steel, which has been around for quite a while, that 20 percent is carbon. A relatively hard yet resilient material, carbon steel is easy to sharpen and holds an edge well. No matter what a knife salesperson tells you, no high-carbon stainless steel blade can match carbon steel's sharpness. Carbon steel is, however, vulnerable in the kitchen environment. Acid, moisture, and salt will stain, rust or even pit the blade if it's not properly cleaned and dried after each use.

There's more, but I'm getting tired of typing. Check out pages 68-69 of the book next time you see it at a bookstore.

 

[grayby]

From the Food Network:
• Carbon steel knives hold their edges remarkably well, require careful cleaning and drying, and will eventually discolor, turning black over time. There's nothing bad about the discoloration; it's a matter of preference.
• High-carbon steel gives you the sharpen-ability of carbon steel without the discoloration. Most professional knives are made of this material.

http://www.foodnetwork.com/food/ck_cg_knives/article/0,,FOOD_27636_4992562,00.html

 

[KellyRedHead]

I have used some soft scrub on mine when I have had a rust spot and it takes it right off.

Kelly V.

 

[ParishKitchen]

Actually, our forged cutlery is not exactly made of carbon steel, as evidenced by the "Cr Mo V" designation.From the cutlery PIG:

The Forged Cutlery is made with high-carbon German steel formulated with special elements to provide superior durability and hardness. The notation “Cr Mo V” etched on the blade refers to the elements (Chromium, Molybdenum and Vanadium) in the steel formula.

Here's a great explanation on cutlery steel grades from http://www.cookswares.com/discussions/cutleryprofiles.asp:

Note on Knife Metals: There are three types of metal alloy used in high quality cutlery today: (1) all carbon steel, (2) high carbon stainless steel, sometimes called "no-stain steel," and (3) very high carbon stainless steel. All carbon steel is the softest, and very high carbon stainless steel is the hardest. In the middle is high carbon stainless steel. All-carbon steel and high carbon stainless steel have the same basic amount of carbon: .45% to .50%. The carbon gives the steel hardness. The more carbon, the harder the knife metal. The difference between the two metals (all carbon steel and high carbon stainless steel) is chromium, molybdenum, and vanadium, which give stainless steel its stainless qualities. They also give the steel added compression hardness and tensile strength. Knife stainless steel has 13% to 14% chromium, and about 1% molybdenum and vanadium together.

• All-Carbon Steel: iron + .45% or .50% carbon. No chromium, molybdenum, or vanadium. Will rust and stain, but softer than stainless steel, so it hones and sharpens easier.
• High Carbon Stainless Steel or No-Stain Steel: iron + .45% - .50% carbon + 13% chromium + 1% molybdenum + vanadium.
• Very High Carbon Stainless Steel: iron + 1% carbon + 13% - 14% chromium + 3% molybdenum + vanadium. Used in Chef'sChoice knives.

German knife producers pioneered the high carbon stainless steel so that a knife's metal would be (a) hard enough to hold an edge, (b) flexible, (c) soft enough to hone and sharpen, and (d) resist rust and corrosion. The formula for German stainless steel is as follows: X 45 Cr Mo V 15 or X 50 Cr Mo V 15X means stainless.
45 or 50 means .45% or .50% carbon.
Cr Mo V means the total percentage of chromium, molybdenum, and vanadium, namely 15%.

Now, I don't know whether our knives are made of "high carbon stainless steel" or "very high carbon stainless steel." I'd assume the latter, but I'll drop a line to HO to inquire.HTH!ETA: Ann, I have AB's Gear book too (and his other books, and the complete set of Good Eats DVDs, and... I'm a total dork)!

 

[chefann]

Thanks, Parish Kitchen!

I had a bad experience with someone at a vendor fair and our knives. All the info I had in my head just took off when he started interrogating me about them. The funny thing (now that I look back) is that he kept telling me that "steel doesn't rust" and "good knives don't need a lot of care." He was so obviously set in his ideas about cutlery that I'm glad he never contacted me again (he never gave me his info, either).

I'm gonna print out what you posted and put it in my files.

 

[abrahamlaur]

i was wondering what those were on my forged cutlery

 

[MissChef]

Well, for starters it's not rust, it's carbon spots...but that's another discussion.
Just wanted to pass on this tip -- a smidge of Barkeeper's friend & a sponge...a few wipes...abd they're gone! Yippee!

Thanks for the info Carolyn and everyone! I just realized my Santoku has some spots on it! Where do you get barkeeper's friend again?
TIA!

 

[jenniferknapp]

Barkeeper's Friend is a powder that comes in a can....just like Comet. And you can find it right around the same area...cleaning supplies! (I think it is near th Old English and that sort of area of my local store)

 

[PC_CPR]

My Bar Keeper's Friend and at least one of the "Cameos" also say they are good on ceramic glass top stoves. So I've asked one of my customers that had the "rust" on their Santoku what they used to clean their stove. If it's nonabrasive, good on steel like Cameo and Bar Keeper's Friend, then it's also good on our knives!

 

[legacypc46]

this thread is so helpful...thanks!