Frizzen Re-Hardening

[Loyalist Dave]

Hey folks what is the going rate for re-hardening a frizzen?  Have you had it done?  Was postage added, and were you satisfied with the results?

Thanks.

LD

[FG1]

Not answer you were looking for but with a propane torch and a few bricks you can do it with kasenit hardening compound .

[JamieMc65]

Well Dave,
I will be doing it as soon as my Kasenit arrives (this weekend hopefully). If I am satisfied with my results and have some Kasenit left, I will be happy to do yours, no charge.
Mind you, this is the first time I will be doing it, and I am kind of a perfectionist. It does not seem that hard and Wyosmith gave me some advice to get started.

I will, of course, take no offense if decide not to take me up on it.
And I apologize up front to any business folks that do this. Not trying to undercut, just trying to help.

[Loyalist Dave]

Thanks for the offers folks.  I have done my own, with Kasenit, but I didn't want to under cut nor overprice myself if I ask for somebody to chip in for the fuel, etc.  when I do theirs.  I have been asked by several folks to do some hardening work.  I was also wondering how many folks get complaints down the line on previous work.  I do it to the right color, and follow the directions scrupulously.  So far so good.

LD

[JamieMc65]

Oh, I understand now.

[LRB]

OK, FYI, Kasenite only goes a few thousandths deep in a typical frizzen rehardening. As far as I know maybe .003, and that may be a generous guess, unless you cook it in for an hour or so. Most US made frizzens are 1095 steel. Not all, but most from quality lock makers. The Kasenite is short lived. A couple of long shooting sessions and it is pretty much gone. If your frizzen is 1095, you will not notice that it is gone, because the 1095 does not need the Kasenite to spark well. The only thing the Kasenite would really do, is prevent carbon loss while you are heating it, and if you don't heat it red hot for more than a couple of minutes or so, you will not have any significant carbon loss anyway. Kasenite has it's uses, but it is very over rated for what it really can do.
PS
  Water quenching 1095 steel the size of a frizzen carries a high risk of breakage.

[Loyalist Dave]

Ah but not all frizzens are made in the USA.     Some of the European frizzens, are only surface hardened, hence the technique of "adding carbon" by wrapping them in leather, then sealing them in a steel can, and placing the can in the fire, then quenching the can in water about an hour later.  That doesn't get nearly hot enough to add carbon, but may get hot enough to harden up a frizzen made of good steel.  I hear it works fine for Pedersoli frizzens from the bess or charley.  

Some of the European and Indian frizzens are not the better grade steel, and really need some Kasenit. I normally do two applications and cook them over the forge when doing so.  Seems to work.  We'll see over the long run though, eh?

LD

[LRB]

If the frizzen is of high carbon steel, you need only to heat and quench, then temper. If it is not of high carbon steel, there are only a few ways to make a lasting fix. You can do an acual pack hardening, similar to the can thing, but more involved, or you can half sole it. That said, you can get a pretty good depth of carbon with the Kasenite if you can cook it in your forge for 30 to 45 minutes, but just a few minutes only gives a few thousandths of depth which will not last all that long.

[James Kelly]

Kasenit has been discussed enough. It iwill make a very shallow case.

f your frizzen is high carbon steel, like 1095, there are a couple of things to do to reduce chances of it cracking in quench, or in use.

First, water quench is usually needed to get full hardness. Water quench can cause cracking. To minimize cracking, and get a faster quench at the same time, use salt water. Roughly 13 ounces of table salt in a quart of water will do.

It might help to wrap the neck in something, or cover it with clay, so it does not quench. Cracking sometimes occurs where there is a large change in seciton size, that is, where a thin piece (neck) joins on to a thick piece (frizzen face)

When you are all done, it is very important that the neck not be harder 'n hell, or one day the frizzen will break & fly away. Selectively temper that neck with a torch.

Best sparking is not necessarily from file hard steel. You might need to temper the whole thing maybe 350F for an hour. Depending upon your personal relationships, and time alone in the house, that may be fairly well done by M'Lady's kitchen oven. Oh, do clean that frizzen first so no suspicious odors find there way into a pie, or whatever!

Finally, this is a metallurgist speaking. An experieced maker, such as Wyosmith might add more practical details.

[LRB]

A brine quench is 13 oz of salt per gallon, not per quart. Being a metallurgist, I trust that you  mis-typed? A frizzen of 1095 MUST be tempered if you want it to stay together. The recommended temper heat is 375°. Those who want larger sparks can go to 400°, but the face will wear a bit faster. Frizzen hardness is a juggleing act. Where as 350° will work, the flint will stop cutting sooner, than if tempered at 375°. Tempered at 400°, the flint will cut longer, the sparks will be larger and burn longer, but the frizzen face will wear faster.
    Now then, the brine quench is most suitable to get max hardness from 1095, but in a thin section such as a knife blade, or frizzen, there is a great chance of cracking. A quench of warmed canola oil is a much safer bet, and will produce an adequate hardness only a few Rockwell points below a brine quench. For the informational benefit of any readers here, 1095 is very low in manganese content, almost to the point of not being, as far as aiding in the hardening process. This requires 1095 to have to cool extremely fast in order to reach it's maximum hardness, and preserve it's level of carbon distribution. The steel has to cool from 1475° / 1500°, to below 900° in about .8 of one second. To do this requires a brine quench. However, a very satisfactory and usable hardness level can be achieved with a commercial oil quench. Of course, no one wants to buy commercial oil to do a few frizzens. It is quite expensive. From tests that I have read, common canola oil comes in just behind the recommended commercial oil, and will give you a very satisfactory hardness for a frizzen, providing that your steel is in the proper heat range when you quench, and NO, that heat range is not as soon as the steel goes non-magnetic. Non-magnetic is only 1414°. you are looking for 1475° or a tad more. Common table salt melts at 1474°, and can be used as a guide to the necessary heat. Keep in mind, you still have to temper after hardening, and the sooner the better.

[James Kelly]

Thank you for your correction. LRB.
Yes I typo-ed, did mean 13oz/gal. Another measure given me by a guy who had worked in very, very rural mideastern areas was use enough salt to float a potato.

I like your practical detailed information for the tempering operation. Will keep it on file. Might maybe put my Lott frizzen back in the oven again, sometime when she goes shopping.

[LRB]

I was pretty sure you mis-typed. I use Mortons sea salt. One 26 oz box in two gallons of water, but only for fire strikers. I've never had the kahounas to try a knife blade. I went to 01 for knives anyhow.  I just hardened seven 1095 strikers and got my first cracks with one, ever. Only on one. They are 1/4" x 3/8"x 2 3/4", but rounded on the face. The cracks were on opposite ends, and opposite sides, short, and the width of angel hair. They are barely visible, even at a really close look. The other six are fine. After seeing that, I tempered at 285°, and found no change in sparking ability. I am going to try 300° on the next to see how that works. In what field do you use your metallurgy education? There are occasions that I have questions on certain steels, and how best to treat them, and what to expect from them. My knowledge is really pretty much restricted to the steels I work with, but occasionally I will get a request from someone to HT a blade, or other piece for them, of a steel I know little about. Take care pard. Wick Ellerbe.

[James Kelly]

Wick-
Education Lehigh University, graduated 1963. Dept head used to work at Springfield Armory, came into class with an M1 rifle. This was the bad old days when we didn't shoot our friends & many college professors were actually men. Stripped that rifle down & part by part we had to say how we would make it. That is, forge it, cast it, machine from bar, cold draw, stamp, &c. Then how would be heat treat the part? Fun class, for me.
Learned about steel heat treating first at Black & Decker, Towson, MD. This was case-carburizing 8620, 4320, tool steels including high speed steel. Mix in some areospace, stainless research and, strangely enough, forging & hardening hammers and axes at the old Kelly Axe plant in Charleston, WVA. 1974- retirement 2007 worked with high temperature alloys, applications generally furnace parts in the heat treat industry. Always interested in history of metallurgy, made my first forge weld in wrought iron immediately before I burnt my first iron.

Maybe you already know this, but brine quenching tends to be faster than plain water, and also means LESS likelihood of cracking. This is because the brine minimizes the steam bubbles that repetitively form and collapse in plain water quench, meaning non-uniform hardening. That is why the (good) old blacksmith moves his part in a figure-8 pattern in the quench.

Much cracking is caused by a decarburized layer on the steel. When you buy hot-rolled steel it has a decarburized surface layer. Grind, machine or file it off. Yes, the decarb layer does not get so hard, wouldn't think it to crack, but it also does not expand as much as the higher carbon beneath. When quenched the core stretches that decarburized surface and it cracks.. Hardened steel parts are larger than when they were soft.

I did not know that canola oil was a good practical home shop quench & will remember that.

As I write this I don't recall if you said whether or not your cracked parts had been forged. Forgings are decarbed and very non-uniform in grain size. All high carbon steel forgings should be annealed to get rid of stresses and make the steel uniform, before hardening. For low carbon steel normalizing is the appropriate treatment. I'd have to look up suggested anneal practice for 1095, me I'd use Bethlehem Steel's old book Modern Steels and their Properties If you don't have one, go on http://www.abebooks.com and get one. Get the oldest one you can, the tan hardcover ones were better than the newer metallic paperback--old hardcover had temper colors shown.
Nicholson File, when I called on them as the tech service guy, hardened 1095 files from I believe 1440F, low, quenching vertically into brine, no temper. If you quench a file, or a knife, straight into the brine it likely will come out straight. Belly-flop it & it is guaranteed to bend, if not crack. Recall that ex-Springfield prof noting that bayonets needed to be quenched straight in, to remain straight.
Always enjoy chatting about metallurgy. Send your questions, don't believe everything I say but check it yourself.