finish for carbon kitchen knife??

Discussion in 'New to Knifemaking' started by KenH, Feb 17, 2013.

  1. KenH

    KenH Well-Known Member

    Hello all, This is a GREAT forum and I've learned a LOT from reading. I'd like to ask a question I'm sure has been discussed in the past, but it didn't turn up in a quick search.

    Is there a general agreement on best finish for a hi-carbon steel kitchen knife? I've made a couple using coil spring steel (5160 perhaps?) for the wife. Cut length of coil with torch, put in gas forge to red heat, pound the steel until it sorta looks like a knife, then grind away rest that doesn't look like knife. Heat to non-magnetic and let cool, trying to get each a tad less heat above non-magnetic that first.

    For heat treating I heated to non-magnetic quenched in 120ºF Canola oil. Very hard, file won't touch. Then bake in wife's oven until done (grinning) (400ºF for an hour)

    Finished to a very shiny finish - like a mirror. Problem: wife says it won't stay that way, as the knife is used, food tends to stain the blade. I had told her to expect a patina to develop much like old time butcher knifes.

    Now, to my question about finish - would a satin finish work better? A satin finish would allow cleaning with a green pad to maintain the satin finish - or that is my thinking.

    How do ya'll normally finish a kitchen knife?

    Ken H>
  2. LiamLynch

    LiamLynch Well-Known Member

    I am far from learned in this matter but I would say get it as close to a mirror as possible and keep it like that by keeping it dry and wiping acidic stuff off it.
  3. Doug Lester

    Doug Lester Well-Known Member

    All the kitchen knives that I have in my block are made by me. They are from some carbon steel or other. They will develop a patina, aka stains, over time. Mirror or satin finish, this will still happen. Remember to use, clean, dry, then put away to reduce it and to prevent rusting. Staining will not effect the function of the knife but rust can.

  4. KenH

    KenH Well-Known Member

    Thanks for the input - One problem with a mirror finish, as the stains occur, they occur in spots. I expect over time, these spots would blend into an even patina, but a few swipes with the "Scotch-Brite" no scratch green pads and the spots go away leaving a nice satin finish to the blade. I'm thinking a satin finish might be best to start with. As the patina forms, any mirror finish will dull over time.

    Thanks again for the input.

    Ken H>
  5. Doug Lester

    Doug Lester Well-Known Member

    If a knife is made to look at then stains are important. If it's was made to use, stains are part of it's history. Rust is another matter, though.

  6. KenH

    KenH Well-Known Member

    Doug, can I get you to talk with my wife about stains? Before I'd make her a knife I got her to understand a few things, NO dishwasher for the knife!!! and it would develop a patina over time. The problem was the splotchy look as the patina starts to form from the first couple of days. With the mirror finish those spots really show up. I took the green pad, scrubbed the blade good to a nice satin finish. I think that solves her concerns. I was just wondering what finish other folks used with hi-carbon kitchen knifes. I'm thinking I'll be doing satin finish only for those.

    Thanks for comments 'n ideas,

    Ken H>
  7. Darrin Sanders

    Darrin Sanders Moderator

    There are many ways to force a patina such as mustard, vinegar, etc. but in my opinion nothing beats the look of a natural patina which takes time. If you leave the stains, in time, they will all blend together and look more even. A naturally formed patina is also an excellent barrier to prevent rust and corrosion. Kind of like a cast iron skillet/pot, the older it gets the better it gets.
  8. Robert Dark

    Robert Dark Well-Known Member

    I agree with Darrin. Problem is....... Most of our wives/girlfriends have been spoiled over the years by using cheap stainless that probably wouldn't cut through hot butter. Just throw it in the dishwasher and it comes out nice and shiney.

    My wife refuses to use one of my knives, stainless or carbon. She says they are too sharp and she is afraid she will cut herself. Go figure........

  9. Doug Lester

    Doug Lester Well-Known Member

    Robert hit the nail on the head, people have fallen for the idea that stainless steel is the only way to go for kitchen knives. How did our ancestors ever survive preparing their food with plain steel knives with all those stains on them? I think my sister still has Mom's old butcher knife that I know she used for over 50 years and she's been gone for over 20 years. That knife isn't stained, it has history all over it. I hope my niece get it when Sis passes, hopefully not for several more years.

  10. Mike Davis

    Mike Davis Well-Known Member

    I do most of my kitchen knives in a 400 hand rubbed finish. If you are concerned with the patina, try this trick. Go get a big chuck roast or something beef of similar size. Oven cook it and dont let it rest. Go right at it with the knife using deep slow draw cuts. The blood will help develop a great, even patina anywhere from blue tones to purple tones. The faster you develop a patina, the better rust resistance you will have. Also it looks wicked to have an electric blue kitchen knife :)
  11. HHH Knives

    HHH Knives Super Moderator

    A patina is a beautiful thing to waste! I dont sand off or use a green scrubber on my carbon blades!
  12. Diamond G Knives

    Diamond G Knives Well-Known Member

    Unless requested, I take all my blades to a hand rubbed 400 grit, then hand rub with a green scotch bright belt or pad.

    My thought on this is that the scratch pattern can be replecated by the green scotchbright pad in the grocery store. I do include written care instructions on how to let a patina form, it's virtues, and the reasons why it helps. BUT you cannot argue with some folks, and if they want their knife to stay "shiney" so be it. Hence the scotchbrite finish so they can bring it back to "original" finish if they so desire.

    God Bless
  13. KenH

    KenH Well-Known Member

    @Mike Davis - I like the sound of that.... "tempered in blood" to give those colors. The wife sure likes her beef raw.... errr, I mean "raw". I'll do that next time.

    @Randy, I agree, I like the patina that good carbon steel has - BUT, I do pick my battles carefully with the wife. Some battles are not worth winning - and I'd probably lose anyway. Remember, the secret to a successful, happy marriage is contained in 2 words: "Yes Dear" :5:

    Thanks to all for the ideas and comments, I do a LOT more reading than posting - trying to learn.

    Ken H>
    Last edited: Feb 18, 2013
  14. Josh Dabney

    Josh Dabney Moderator

    I'm with Randy on this one. Attemps to thwart a patina on a Carbon Steel kitchen knife will be aggrevating. A full on patina will form pretty quickly and any new stains will blend right in.

    IMHO many put too much emphasis on carbon -vs- stainless. If a Patina isn't your thing... or your wife's thing ;) go stainless for your kitchen knives.

    In my house we kinda agree. My wife doesn't mind the patina and I don't mind when she leaves blades laying around for awhile with food on the blade or water spots on the blade or "soaking" in a pan of water or... or... or.... LOL.

    I enjoy making and using my carbon steels but I've made some for the kitchen in ATS-34 also depending on who the end user is going to be. They make fine knives and won't stain a lick.

    The secret to carbon steel happiness though is to NOT attempt to remove the stains with each use but let them form and welcome the character the blade takes on with each use.

    Thats my humble opinion

  15. Michael Kemp

    Michael Kemp Well-Known Member

    Mike - I've had that happen on mirror finished 5160 - it's a cool look. If you can't "sell" that to your S.O. - here's another tack: I've got a small utility (or large paring?) knife I made of D2 which is not really stainless. After taking it to a satin finish I did 3 cycles of: soak in dilute ferric chloride bath/rinse/soak in dilute Brownells Bluing bath/rinse - repeat. The resulting black patina has held up fine. You still have to dry-after-using or the bare/sharpened edge will rust, but sweetie & I are happy using it. And yes - she LOVES having sharp knives in the kitchen. I really don't know the ratio of FeCl3 to water - or Brownells to water - for the baths - but pretty dilute. About 20 minute soaks. Probably makes a difference how hot a day it is too.

    ~ Michael Kemp
  16. KenH

    KenH Well-Known Member

    Michael, let me see if I've got this straight - soak in Ferric Chloride for about 20 minutes, then rinse (really good), then soak in dilute Brownell's Blueing? Hmmm, I might try that one some of the knifes I make. I've about convinced the wife the patina will look good once it's set solid. Just give it a bit of time<:)

    Yep, she now likes sharp knifes - you should hear the wife fuss after working in her sister's kitchen with her dull knifes. Wife said she'd never had sharp knifes before meeting me. We both met late in life.

    Thanks for all the good ideas.
    Ken H>

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