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Hardening with Satanite

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I've been reading some of the stuff about hardening with satanite and finally got around to buying some.  I have a few questions though that you guys could probably answer.  What is a good consistency to mix the satanite for the blades?  Is it a good idea to put a thin coating on the edge as Yoshihara Yoshindo does in his book with his clay?  I have two blades I'm going to try this on.  One is L6 and mild steel and the other is L6 and 1095(mostly L6).  What quenching medium would be best for these combinations?  What is a good color(or temperature) to draw a temper after the hardening?  Any more advice will be gladly appreciated.  Thanks for your help.

 

Patrick

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Well this looks like a good place to throw my two bits in.  I just got through doing a quench with Satanite clay coat about an hour and a half ago.  First time with any kind of clay coat for me ;-)  So here is what I did and what happened.  First, I used straight Satanite - no additives.  I mixed it fairly soupy but it coated on the blade pretty well.  I might be tempted to make it a bit stiffer next time around  Probably got 1/8 inch thick on the blade (maybe a bit more in places).  I did the "crows foot thing" (I think that what it's called) by putting thin lines running from the blade edge towards the back and spaced them every 1\2 inch or so. Then I coated the whole back half with a good layer and a wavy edge toward the sharp side.  Scraped off the back of the blade (supposed to limit the arching of the blade).  So - it all dried on pretty securely but shrunk back off the blade in a couple of spots - so I touched it up the next day.  Tonite I heat treated in  and quenched it in a bucket of brine (enough salt in the water to float an egg).  First thing into the dunk I saw clay blasting off the blade.  I ended up with a bit of a patchy look to the blade but I really don't know what to expect after it's polished yet.  I gave it a rough sanding with worn out 180 grit emery cloth and put it into the oven at three-fifty for the first time.  What I noticed that I didn't expect, is that where I made the crows foot lines, there is a noticeable ripple in the steel because the coated steel shrunk where the hardened stuff didn't.  Kind of interesting and aught to give it a serrated effect.  Sanding should moderate some of the ripple though.  Next time around I'll keep the lines off the edge though.  Since this is supposed to be a utility insulation cutter for a working man (my nephew) I think I'll leave it and see how it works out for him.  I was really impressed with some of the patterning that Tai Goo gets with his clay coats though so I'm planning on doing a lot of experimenting with this kind of thing.  My big question of the day is what can I do to keep the clay from blowing off the blade at quench time?  I've read Tai's receipe for Porclin clay and will probably get around to trying different stuff but is there a usual additive for the Satanite?  Lard? Scale from around the anvil? Wire wrap?  I've heard of all of these things in various contexts.  I think Mr. Engnath's site said with the Satinite it wouldn't need a wire wrap - could have that one mixed up with another? Come to think of it maybe that was the Venerable Mister Fogg said that...  As I mentioned though, I really don't know what to expect with a polish on the blade.  We'll see soon enough ;-)

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Here's my thoughts.  The Japanese smiths don't use Satanite or any kind of hardening refractory cement.  Just clay with their secret additives according to their traditions.  I've never heard the lard story.  The last time I tried to cook a bratwurst in the forge was nearly twenty years ago and I dang near burnt down the shop with that grease fire.  If you try that one, have somebody videotape it, I'll turn you in for the Darwin award that I didn't win.  

 

Make the mix soupy enough to flow but not pasty.  They don't use wire wraps.  I knew Bob, he used wire because he put the stuff on about a half inch thick at the back and it was hard to get dry.  He was a real pioneer for us all.  

 

Places where the coating cracks allow the forge atmosphere to get into the blade steel, you may find that all you have is a little scale formation under the clay.  

 

If the Satanite is spalling off, either the blade is finished too smooth and there's nothing for the cement to grip, or it's not dry enough yet and is getting steam loosened enough to pop when in the quench.  

 

Brine is hardly necessary.  Good clean water is fast enough to crack a blade right quick if you're not carefully paying attention.  But Grayangel didn't say what kind of steel anyway.  

 

The L6/mild mixture will tolerate water better than the L6/1095 mix.  I'd still use water, but that's what I do anyhow.  Oil doesn't give the real snappy hamon or some of the nie/nioi features that are really desirable.  I'd leave the back coated.  Hardening the spine (muneyaki) is not well regarded by the purists.  

 

Some folks don't temper blades done this way.  Sometimes tempering will relax the sori (curve) a bit if it's too deep.  Set the tempering oven for 375 F and leave it in there for two hours.  It won't hurt anything.  

 

Get some pictures of your efforts guys when you have the chance.  Show and tell is always good.

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If the Satanite is spalling off, either the blade is finished too smooth and there's nothing for the cement to grip, or it's not dry enough yet and is getting steam loosened enough to pop when in the quench.  

 

Hmm,  Not sure if I agree with that last but I'll watch for it in the future.  Did get pretty bad spalling.  Actually liked the patterning it made on the steel with raised and and lower spots.  Looked kind of like a cracked lakebed pattern.  Might have to do one and leave the pattern but it starts to dissappear pretty fast when sanded.  What would be considered too smooth for the blade at this stage?  I usually do 180 grit up to the quench.

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I have been playing with water hardening 1050 lately and find that what Mike says is true. If the Satanite is not completely dry if will pop off at quench. Wire is not necessary and if you are having to add the wire to keep the clay on during the quench something is wrong....I am often having to grind my clay off after hardening!

 

I am using a 50 grit finish right from the grinder to apply clay to. And I wash the blade in dish soap and then again with Windex before wiping it down with alcohol just before applying clay. I put those little disposable vinyl gloves on to keep my finger oil from contaminating the surface. Any oil at all will cause the clay to seperate from the surface.

 

A very rough, very clean surface takes and holds Satanite like a bandit.

 

Just my limited experience.

 

Brian

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I'm ready to heat treat at 50-60 grit depending on what belts I buy.  Brian is right about cleaning the blade before putting on any clay.  Leftover oils etc will interfere with the clay sticking to the blade too.  

 

Dry clay is critical.  The stuff can be hard on the outside and still have water underneath.

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Guest OleyFermo

For what it's worth, I've been using satinite for over twenty years.  I mix the stuff to a creamy consistency so that it can be applied either in a very, very thin coat... or 1/4 inch thick... depending on what I want out of the blade.  I don't let it 'dry' at all.  Satanite goes on the blade, thick or thin... and the blade goes directly into the hardening forge (propane fired) which is already up to temperature.  Blade finishes I've used satanite on vary from a sandblasted surface to something that's been taken down to 280 grit, or finer.  I've had no trouble with the satanite coming off any of the blades.  In fact, I have to scrape it off the blade with a blunt chisel directly after the quench.  Most of my blades are quenched in oil... either peanut oil or commercial quenching oil... but the blades I've quenched in water didn't lose any of the satanite either.  Put the satanite on the blade, the blade into the fire... and when it's up to temp, quench.  Just my two cents worth... and considering inflation, two cents ain't worth much.

 

 

Jimmy Fikes

 

:;):

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Well the consensus seems to agree that the stuff doesn't come off... :o).  So I gather from all this that I probably need to use a pretty thin coat.  I was amazed at the difference it made in the results by having the thin lines running down the side (ashi). Wouldn't have thought they would affect the hardening so much.  I expect my problems arose from having thicker and not very even coating.

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Having re-read the original post and question I wanted to add a little more to the mix.

 

In terms of consistency, I have been mixing it (Satanite) to a pudding like thickness. Like cake frosting. It is easy to spread but not runny or watery. I don't put a thin coat on the edge...I just leave the edge bare steel. I am playing with ashi but really prefer a more suguha type of line. Just a plain line with clear habuchi (hardening line) is fine for me. I add finely crushed soft firebrick and a small amount of finely powdered charcoal to my mix and let it dry completely. I recoat any cracks that occur as it dries and tend to lay it on *real* thick on the back.

 

I have very little experience with L6 and have no advice as to quenching media except to add that L6 is a low alloy steel and you have a matter of seconds to get behind the nose...like 6 - 15 seconds I believe. L6 hardens pretty well in air so I would guess oil is fine (best) but I do know that some folks use water. 1095 can be *rEaL* tweaky in water but if you are differentially hardening a L6/1095 pattern welded steel remember that you will most likely get a downward curve quenching into oil with a clay back so you may want to precurve the blade to compensate for this. Peanut or safflower oil works good and it is fairly cheap. If you get good at it I would recommend using a known quenching oil made specifically for quenching.

 

I temper my 5160 and O1 at between 375f and 475f depending on what hardness I'm after and how tough/long the blade is. Bigger/longer blades get tempered hotter for a longer time. Short blades are fine around 425f or so and my guess is that this is also true for L6. If tempering by color, start your first temper at a straw yellow color and then temper for an hour and check your hardness at the edge with a brass rod. If it is chippy or too hard temper again to dark golden yellow or a little warmer.

 

It is always interesting to me that experienced folks find completely different ways of coming to the same conclusion or that some folks use the same techniques and get completely different results. The truth is that there are a lot of variables when using different steels/clays/quench media and that experimentation and experience/determination are the most critical factors. I use what works for me and have often found that things that are written in stone for me prove disasterous for other guys using exactly the same methods. And vice versa. In this thread alone you have guys who have good success with wet clay and dry clay, 50 grit to 220 grit, thin clay and thick clay. Try all ways at least twice and never quit or give up. And believe that it will work and quench decisively and with conviction. Your mental state matters.

 

Good luck, Patrick!

 

Brian

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Thanks for the help guys.  I'll be trying this stuff out tommorrow, but I don't have a digital camera, so it'll be a while before I can show what I've done.  Thanks again.

 

Patrick

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I mix some crushed-up soft firebrick sometimes, but otherwise, like Fikes said.

Worked great just yesterday...

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I tried Fike's method today and so far I think it looks pretty good.  I haven't polished it up yet, but I think it worked!  Thanks again guys.

 

Patrick

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RHGraham Very nice blade Super , how thick did you put it on that blade?  did you use crushed firebrick (soft or hard?) in the mix?

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Satanite and crushed soft firebrick, roughly 50-50, the firebrick just gives it a little more body like I prefer, maybe a bit more insulation perhaps. I brush a thin coat on first then eveything else is like 1/8 inch or maybe 3/16ths thick at spots. It doesn't take much clay to do the job, I find the austenizing temp more important.

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RHGraham what temp do you take 1095 to before you quench and how long do you hold it at that temp?  Also what happens above or below that temp?  does the pattern walk one way or the other?

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There are varying ways to go about it, but with steels over about .8c I try to get around 1400-1425 f and my hold is about 2 minutes or so, i come up to that temp really slow and always get much better results when I do.

 

A little lower is possible, but the soak times to get it to go non-mag get much longer and you need salts generally to pull that off, which I don't use.

 

Higher temps up to around 1500f will work fine too, but at that temp and above the hardenability drops off... at around 1550F the hamon will be forced low on the blade, with a steel like 1086M for example, if you austenize it at 1550 you'll get a straight even hamon about a 1/4 inch up from the edge without any clay at all if you were really anal about the normallizing.

 

Under around .8c higher temps work better for austenizing, at least for me, 1050 I have to push up to about 1500F or so to get it to do what I want.

 

Seems to all work differently, a little sometimes, sometimes alot, for different folks, so your mileage may vary.

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Hey R.H. I thought I read a sword forum artical that showed you useing a salt pot named "scud". How do you judge your aust temps in the forge? Thermocouple? I have been forgeing 1065 and haveing fits trying to get a hamon as well as I can on 1095. My temp judgements are by eye though.

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Ahh, good ole scud.

Scud is living a fine and well-fed existance in al Massey's shop these days, good home for him.

 

Well, temp judgement is a many faceted thing I think. I simply practiced a lot of variations on technique untill I came up with a routine I could repeat and 'tune-in" when I needed too. I do have a pyrometer that I use to calibrate myself with occasionally, to confirm what kind of ranges I'm in, and I have an infrared pyro on my " i really really want that " list.

 

Basically I have a very responsive forge, very adjustable, and I can be very deliberate in raising the steel in temp slowly to specific stages, and by going slow with lots of soak I can sneak up on really low austenizing temps. I use a simple magnet for 99% of my heat-treats.  So typically I'll bring a blade up to somewhere in the 1250-1300F range and stop there for awhile for a soak of a minute or two, then add some fuel bit by bit to bring it up to a point, again very slowly, where I begin to see a hint of accalecence occuring... or there is a little definitive strip of orange appearing on the edge of the otherwise red blade. And I stop adding gas and wait for awhile, the colour will start spreading towards the rest of the blade, if it seems to recede or stop I'll meter a tiny bit more gas, and eventually, the blade will turn the nice low-orange colour all over...  

 

... at the same time I get a soak happening at the red stage, the first soak point of 1250-1300, I get my magnet and when the orange strip shows up, then I start touching with the magnet occasionally, especially the thick points, to judge when I've soaked all the way through the steel....

 

Once it's non-mag, nice low-orange all over, I hold it there again, probably 2.5 or 3 minutes usually, then I quench.

 

I've cross-checked this method often with some kind of pyro, in an effort to get some numbers recorded for understanding of the process, but if you make a real point to be methodical and most importantly, slow and deliberate, you can be pretty accurate and do high-quality heat-treating without high-tech gear. The high-tech gear has an important role to play as well however, so you have to make judgement call over what kinds of techniques and technologys will suit your own situation best. The method I described I came to before I had the ability to actually detect what temps I was at, it was developed by simply testing test blades and keeping notes.

 

time n temp time n temp time n temp

havin a shop rap helps

 

1065 has a lot of manganese and because of that it has the stupid idea it should harden deep and fast no matter what YOU want it to do.

Austenize it hotter, I'd probably use the method I described before, then take it up another visible change in the colour range, a nice bright happy orange, about 1500-1550F.

 

The fun part is that you will see the colour in your shop, with your eyes, completely differently than I will.

So good luck dude.   hehehehehe

 

Go slow, trust the magnet.

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I love the way you write Randal. Are you heat treating in the forge that you posted a picture of recently? Great control, I would love to see the burner set up.

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Yeah, the forge I pictured is the main fire in the shop at this point, I do everything in it.  I'll get some more pics and post them one of these mornings. It's got a simple venturi I designed, a needle valve, and a hose...it runs off tank pressure.  I had two other forges for a while but I ended up using this one all the time and for the bladesmithing gig and have had no need for any other fire. I have the other two broken down and I'm using parts for a small crucible furnace, then I think I'm done as far as gas-fired stuff is concerned.

When it's at a stable idle the pyro indicates it's right around 1500F on the liner, which with small blades gives me around 1400F in the steel, so it's super convienient. If I slide the brick aside it'll beeld of some heat and I can just lay things on the forge bottom and little knives and chisels will lie there and soak at 1275-1300 for as long as I want.  On the top end I think it gets close to 2900F, I can do small crucible melts in it.

Here's a pic of one very similar I built for another maker...

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I wanted to say as well that with all the work I've put into forges since that first time we talked about them, wow, quite a while ago now, my whole quest was to find the same kind of controll and versatility as the charcoal fires had, being able to controll the fire completely, all the time, was the main thing I tried to get. Propane forges, at least in my expierience, come close, but they just don't quite make it. On the upside, I have a small high-powered fire that takes up a small footprint in the shop and can be moved anywhere it needs to be, including other shops, with a common easily available fuel.

 

I feel the circle closing though, the scrap-wood pile in the yard is gettin pretty big...

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Thanks for the lesson Randal. It's obvious now I am rushing things in the heat treat. I'll slow down and keep better notes. thanks again.

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RHGraham can you post plans for your burner?  So it doesnt have a small orifice like a welding tip or anything like that, just a needle valve?   Also what do you etch your blades with to get the Hamon to show like that?

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While there are questions for Randal; do your burners incorporate a flare or flame holder? Also, how far does the burner extend into the forge, and how is it held in place (is it readily removable?).  By the way, I like the way the burner enters from below, giving the flame more time to spread out before it contacts the steel.  Its a nice feature that's obvious once you see it, but that I haven't seen on any other forges.

 

Cheers,

 

David.

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Hamon; it can vary alot depending on the steel etc, but my most often method used is warmed lemon juice. vinegar works ok, on occasion I have used nitol as well which is nitric acid and alcohol, very weak mix. And on occasion I do it with the fingerstones, but to be honest that ranks right up there on the fun scale with a hemmaroid.

Check out Samonji's website (Brian Van Speysomethingorother), he has gret info there on polishing and etching.

 

Burners on my forges are attached just to the outside lip of the entry hole, and I tack-weld them in place. I find other methods get loose from the heat and got tired of messing around with fried bolts and screws. Plus I'm kinda a redneck, so I weld pretty much everything anyway. Don't like it when stuff falls apart.

 

Straight 3/4 inch bore burner, no flare or flame holder on either my venturi or any of my blower-burners, I find them unnessecary and that they add to the complexity, I like simple. I don't need any of my burners to burn outside the furnaces, so I don't see the point.

 

The venturi burners I use have a .030 orifice, i think, my notes are at the shop so I'll check it and post if I remembered wrong. The barrels have 4 half-inch air holes.

 

I have strong feelings about flame-length, and it's importance in a good clean burn with good efficiency. Having the burner on the bottom wraps the flame around the forge lining as well as anything I have in it contributing to an even strong heat. I don't like having  partially burned flame contacting the steel either.

 

Don't have plans yet, I will later, in the meantime I'll have 8 or 10 of them for sale maybe next week. Probably $45 or so apiece

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