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Tamahagane tanto wip


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8 hours ago, Francis Gastellu said:

 

Ah yes, thank you. I'm not as familiar with brine, but what you suggest sounds like a more extreme version of what water to oil tries to do? Interesting :)

 

Well, I'm already fighting second thoughts about _that_ plan, so safe to say I'll pass on the brine ;)

While brine is a faster quench than straight water, it is actually less prone to cracking as the transition between the vapour and nucleate boiling phases of the quench is less violent. Depending on your edge thickness I'd go with a 2 or 3 second quench in brine, or at least water with a lot of dish soap (also destabilizes the vapour phase and acts as a surfactant), finished in slow oil, and immediate temper.

Jake Cleland - Skye Knives

www.knifemaker.co.uk

"We can't solve problems by using the same kind of thinking we used when we created them."

"Everything should be made as simple as possible, but not simpler."

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."

 

Albert Einstein

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Brine solution is less stressful in the quench because of a finer vapor jacket.

 

Doug

HELP...I'm a twenty year old trapped in the body of an old man!!!

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5 hours ago, Doug Lester said:

Brine solution is less stressful in the quench because of a finer vapor jacket.

 

Doug

 

12 hours ago, jake cleland said:

While brine is a faster quench than straight water, it is actually less prone to cracking as the transition between the vapour and nucleate boiling phases of the quench is less violent. Depending on your edge thickness I'd go with a 2 or 3 second quench in brine, or at least water with a lot of dish soap (also destabilizes the vapour phase and acts as a surfactant), finished in slow oil, and immediate temper.

 

Thank you both, I would have equated faster quenching medium with more stress.

 

My original plan was to go for 3s in ~70C water with dish soap, 3s out, then the rest in warm oil.

 

However my original plan was also to have a 2.5mm edge. I had to remove some more material after taking a closer look with a magnifying glass, and my edge is now thinner than I'd like, just about 2mm at the machi, just under 1.5 at the tip.

 

I have water hamon envy but right now I'm leaning towards Parks 50 because of my edge thickness, which I've been assuming is a bit thin for brine as well. Should I reconsider?

 

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I did some more shaping and decided to go for a kanmuri otoshi zukuri profile. Should I mention that I did so in order to grind out an inconveniently placed crack that I had missed?

 

AF1zE1y.jpg

 

fdQcyBg.jpg

 

I actually find that it helps balance what is otherwise a fairly narrow tanto, and gives it more character than hira zukuri does.

 

It's under a drying layer of ATP 641. Tomorrow, normalizing.

Edited by Francis Gastellu
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I would try water or brine solution more on the temp of 140°-160° but your idea of getting some Parks 50 or some other fast commercial quenching oil has merit.  Tradition Japanese sword makers who quench in water consider a 25% failure rate to be acceptable'

 

Doug

 

P.S.  Your blade is looking great.

Edited by Doug Lester
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HELP...I'm a twenty year old trapped in the body of an old man!!!

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13 minutes ago, Doug Lester said:

more on the temp of 140°-160°

 

Well I meant celcius, you mean fahrenheit, right?

 

13 minutes ago, Doug Lester said:

Tradition Japanese sword makers who quench in water consider a 25% failure rate to be acceptable'

 

Yeah :ph34r:

 

If I hadn't needed to go thinner (and ahem... crackier) than planned, I'd accept the risk as par for the course (though I would finish in oil rather than traditional water-only). As it is, it feels like I'm compounding the risk factors for the hope of a more contrasty hamon, and a voice in my head says I'm probably being too greedy ;) 

 

Then again I was ready to restart from scratch a week ago, so... no pain no gain? yolo? :P I'll figure it out :) 

 

22 minutes ago, Doug Lester said:

P.S.  Your blade is looking great.

 

Thank you! 

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The problem with Parks 50 is not so much loss of activity as loss of sori. On that sugata, uchi -sori would be unusual, but not outlandish, and it looks like you still have plenty of width at the kissaki compared to the machi, so any negative sori could probably be ground back to mu-sori. It's a judgement call - 1.5mm is not insanely thin for an interrupted brine quench finished in oil, but it's always a risk. Somewhere on here Jesus Hernandez had a post about quenching a thin blade into hot parks to produce positive sori, but I'm not sure how repeatable that was...

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Jake Cleland - Skye Knives

www.knifemaker.co.uk

"We can't solve problems by using the same kind of thinking we used when we created them."

"Everything should be made as simple as possible, but not simpler."

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."

 

Albert Einstein

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13 hours ago, jake cleland said:

The problem with Parks 50 is not so much loss of activity as loss of sori. On that sugata, uchi -sori would be unusual, but not outlandish, and it looks like you still have plenty of width at the kissaki compared to the machi, so any negative sori could probably be ground back to mu-sori. It's a judgement call - 1.5mm is not insanely thin for an interrupted brine quench finished in oil, but it's always a risk. Somewhere on here Jesus Hernandez had a post about quenching a thin blade into hot parks to produce positive sori, but I'm not sure how repeatable that was...

 

Agreed I didn't mention negative sori but that's definitely another motivation to stay away from parks 50. My last tanto got a noticeable uchi sori, and although it works fine on that piece, it wouldn't be my default choice.

 

I don't expect to pick up a lot of sori with a 3s interrupted water quench finished in oil ultimately, but if I can avoid it being negative at all, that'd be a win. How much would you typically expect on a small blade with 2/3s in brine?

 

Good to hear that brine isn't out of the question for my edge thickness, now I need to make a decision...

Edited by Francis Gastellu
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Yesterday I normalized and refined the grain at 1600, 1475, 1450, 1425 and 1300 F. I attempted to use anti-scaling (ATP 641), which I'm not used to, and the coating cracked on the first cool off. I actually stopped and reapplied it, aiming to not let the blade cool down as much (although still to gray) and that worked for one cycle but peeled off after that. I decided to finish my normalizing heats without re-coating because this was a pain. Next time I'll use SS foil again, that works better for me.

 

I cleaned up the blade again and started applying the clay.

 

I've gone through many rabbit holes looking for clay recipes, and the difference between edge and spine clay. I found out about vapour phase and grit and shrinkage and cellulose and I sure didn't understand everything I read. Ultimately I chose to use satanite as a base, because I've had good experiences with it. For the thin edge clay I added powdered charcoal, and for the thicker spine clay I added iron oxides (in the form of crushed scales from the forging of that blade, which I find both appropriate and oddly satisfying). 

 

This isn't anybody's specify recipe (that I know of, though i'm sure that's been used before), this is just an attempt at being a little bit closer to what I've gathered from the classical sources, while still working with what I have. I don't know if these did anything other than make it easier to see the difference between the two different kinds of clay while working.

 

I attempted a somewhat tight choji hammon but didn't do the neatest job... so we'll see how that goes :ph34r: Fun fact, it took me 5 tries to complete the claying without messing up one way or another :unsure:

 

HihD6Us.jpg

 

I let the blade dry overnight while I was still consider my quenching options.

 

I woke up this morning and decided to go with brine. This way, if it breaks, I have other people to blame instead of myself. Smart eh? B)

 

My quench tank was 5 gallons, which I figured would be enough for an interrupted quench on this short blade. I ended up using about 9 pounds of salt (enough for a fresh egg to begin floating), gave a very generous squirt of Dawn into the tank, mixed it all up, then dunk an immersion water heater on a thermostat with a temperature set to ~160F (70C).

 

I'm using a heating treat oven and consistent with my normalizing temps I'll be treating this as a simple steel. I soaked for 8m at 1450, then aimed for 3s in the brine, 3s out, and the rest in oil (parks 50, though at that stage it shouldn't matter much)...

 

It survived!

 

wOnhRJa.jpg

 

 

I had a notion to capture a video of the quench since the tank is transparent. In fact, I did... but what I didn't realize was how opaque brine was :D Here's a framegrab of this dramatic quench right in the middle of the action:

 

dUuULTY.jpg

 

At least that allowed me to review my timing, and in fact I quenched for barely over 2s. We count faster when we're under pressure... the blade still picked up a slight sori, at about 1/16", which I'm very happy to work with.

 

Op2CbAL.jpg

 

I tempered at 400F for two 1h cycles. I used the second cycle to take out a slight bend in the tip, by clamping the blade between two flat bars with a 24 gauge shim in the oven. It took some sanding but I got past the the decarb on one side of the edge, and the 60 RC file seems to skate fairly consistently.

 

Phew.

 

A sneak peak at the hada and some hints of the hamon:

 

52odP2A.jpg

 

FiMTATr.jpg

 

mqMalG4.jpg

 

Z0e2ltt.jpg

 


It looks like it might end up a little close to the edge in places, my shorter quench or my clay layout are surely to blame. I think I can make it work, but as always, we'll see!

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Psych. I know I said the file skated, and it still seems to as far as I can tell, but the hamon dips into the edge.

 

Can't work with that, I'll be re-hardening, yay! :rolleyes: 

 

odeDoE1.jpg

 

My plan to solve this next time: 1) much less busy ashi lines, 2) quench for actually 3s in the brine. I'm also thinking about raising the quench temp to 1475, though that's a lot of variables to change all at once.

 

I'll also try to degas my clay with the vacuum chamber, as I suspect bubbles caused little circular scale marks in several spots (i'd be surprised if they wouldn't show up in a final polish).

 

Well, I wanted to learn and I'm learning, so all's well.

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Raising the quench temperature will help, since tamahagane has no manganese to promote deeper hardening.  Homemade steel usually requires a more drastic, for want of a better word, quench.  

 

The hada looks great!

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Your ashi look fine - that looks like just a temperature issue to me. It occurs to me that if you're soaking for 8mins in an electric furnace, you might want to substitute anti-scale for the edge wash, or decarb could become an issue, though the charcoal in your clay may be enough...

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Jake Cleland - Skye Knives

www.knifemaker.co.uk

"We can't solve problems by using the same kind of thinking we used when we created them."

"Everything should be made as simple as possible, but not simpler."

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."

 

Albert Einstein

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2 hours ago, jake cleland said:

Your ashi look fine - that looks like just a temperature issue to me. It occurs to me that if you're soaking for 8mins in an electric furnace, you might want to substitute anti-scale for the edge wash, or decarb could become an issue, though the charcoal in your clay may be enough...

 

Thank you for your assessment, I'll focus on temperature.

 

Substituting with anti-scale makes good sense but I wasn't too impressed with how well ATP641 adhered on the blade so I'm hesitant but it is worth considering.  

 

Thanks again!

 

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Good news and bad news B)

 

The good news is the blade survived another quench in brine (thank you guys for suggesting it!), and though the hamon is still quite close to the egde in places, it's not dipping.

 

1dSK683.jpg

 

The bad news is that I didn't get all traces of the cracks out:

 

jFCnWPZ.jpg

 

The white patch is a tiny surface crack I seem to have missed, and the white wispy lines are shadows of cracks I had removed, where I am guessing decarb went much deeper than for the rest of the blade.

 

I suspected that might be the case but I knew I was getting very close to the core and I couldn't just keep grinding...

 

Well, the other bad news is that I finally went through:

 

CVpkxZD.png

 

This is the coup de grâce for this blade. I'll still use it as polish practice but this one is eventually destined for the wall of shame.

 

I'll be starting over in the next few days. Obviously I would have preferred if this had worked out but the point of this was to practice something new, so it was time well spent. I will do my best not to make the same mistakes again (especially not the dumb ones, like forging too cold -_-) and to hopefully do the rest a little better still.

 

Oh, before I forget, I thought I'd share this animation I made to compare the clay and its effect on the hamon. Obviously my blade had issues so this may not be representative of what to expect, but I find it interesting, and I will change a couple things based on what I am seeing here:

 

UWINErb.gif

 

 

 

 

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I wouldn't necessarily count it as a failure! I understand the issues with the core and the cracks, but there is a chance the cracks will polish out, and the core steel showing is something seen on nearly every nihonto still surviving, except for those that have seen fewer polishes. I would use the blade as a polishing practice to evaluate the quality of the hamon, and if you end up wanting to, you can use it as a quenching practice piece to try and form hamon out of the fire instead of using an oven, I find that having a heat differential caused by using the fire carefully instead of the eveness of a kiln can be very beneficial. I do all of my hamon without clay, so the technique is slightly different, but I think you may benefit from practicing with just the fire and clay instead of the oven. 

 

I am glad you're going to start again and give it another go! Your carbon levels seemed good, and you were able to get a nice midare hamon with bright nie. please show the polished surface when you get a chance!  

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15 hours ago, Alan Longmire said:

It was a valiant effort, regardless of outcome. You should still be proud of yourself for getting it this far!

 

Thank you Alan, I'm actually encouraged by this initial result in spite of having to start over. I might have been a bit optimistic to think I could get one of those done the first time I tried I suppose ;). Well... I still don't really know what I'm doing but I have a better idea of what's waiting for me, that's progress :P 

 

11 hours ago, Emiliano Carrillo said:

I wouldn't necessarily count it as a failure! I understand the issues with the core and the cracks, but there is a chance the cracks will polish out, and the core steel showing is something seen on nearly every nihonto still surviving, except for those that have seen fewer polishes. I would use the blade as a polishing practice to evaluate the quality of the hamon

 

Interesting thank you, I didn't realize. I'm not close to where I need to be on that edge yet though, so I'll be looking at a lot more core steel by the time I'm done.

 

I definitely want to use it for polishing practice. I will basically "finish" the blade more or less, but I won't be making fittings for it and consider it "completed". That's a part of the build I'm very much looking forward but I don't want to have second thoughts about the blade it's for, it's just too much time and focus to give half-heartedly.

 

12 hours ago, Emiliano Carrillo said:

you can use it as a quenching practice piece to try and form hamon out of the fire instead of using an oven, I find that having a heat differential caused by using the fire carefully instead of the eveness of a kiln can be very beneficial. I do all of my hamon without clay, so the technique is slightly different, but I think you may benefit from practicing with just the fire and clay instead of the oven. 

 

I hear you, thank you, and I must admit that using an oven isn't quite keeping up with my initial aim of following a somewhat traditional method as stated in the original post to this thread. My comparatively short background in blademaking has always been with modern and known steels for which the benefits of ovens are a lot more evident. In time I have become rather reliant on this. This is clearly an area for improvement, as even if I were to dial in my process exactly right for this particular batch of tamahagane, the next might be quite different, so this is not a reliable approach.

 

I don't think this blade is the right one to practice this though, because with so little edge steel left (at least one one of the side) the effect on the resulting hamon is a bit questionable. I have some W2 laying around though and will see how easy or hard it is for me to rely on decalescence through the clay.

 

12 hours ago, Emiliano Carrillo said:

I am glad you're going to start again and give it another go! Your carbon levels seemed good, and you were able to get a nice midare hamon with bright nie. please show the polished surface when you get a chance!  

 

I will and thank you for your encouraging words!

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This is still a wonderful project and very informative thread for those of us following along. I'm very glad it got pinned and will be easier to find in the future.Maybe you could add your next endeavor to this one and compare results and process? Thanks again for taking the time to document so well.

Edited by Joshua States
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“So I'm lightin' out for the territory, ahead of the scared and the weak and the mean spirited, because Aunt Sally is fixin’ to adopt me and civilize me, and I can't stand it. I've been there before.”

The only bad experience is the one from which you learn nothing.  

 

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15 hours ago, Joshua States said:

This is still a wonderful project and very informative thread for those of us following along. I'm very glad it got pinned and will be easier to find in the future.Maybe you could add your next endeavor to this one and compare results ad process? Thanks again for taking the time to document so well.

 

Thank you Joshua, and definitely, I'll continue on this thread with my next attempt.

 

 

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I have enough material for two more stacks. I'll be doing the next one the same way I did the first, with paper, clay slurry, and straw ashes, and the second without. I understand some smiths forgo those in gas forges and still manage to produce their desired results, so it'll good to see if I can simplify the process for myself as well. This will be for a future blade, or if it turns out that this doesn't work for me, I'll have shingane (core steel) ready to go for this one :)

 

X5GhYlh.jpg

 

For now, we'll focus on this guy, starting at 1.32kg.

VhdCDcB.jpg

a0EeIWh.jpg

YrOfVGH.jpg

 

The paper, clay slurry and straw ashes start disintegrating fairly rapidly. I suspect this is to be expected in a gas forge, and part of why I want to try the next stack without it. One thing I do not know is what kind of clay slurry exactly is normally used. Here I am using a fairly dilute mix of pottery clay and satanite.

 

lLQKLV6.jpg

 

There are a couple things here that aren't clear to me about the process:

 

1) The clay slurry, which traditional Japanese smiths later pour all over the hot billet as a flux, is only used initially to soak the paper holding the stack. There will be some seepage obviously, but not very much... why not pour clay on the stack prior to wrapping it? (or both really)

 

2) The straw ashes, which as I understand are meant to mitigate the loss of carbon, are put on top of the stack, but traditional Japanese smiths then bury the stack in charcoal, which has plenty of carbon, so again, why?

 

Ik3wfrm.jpg

 

Getting past the initial consolidation and first fold is still quite challenging to me. I did better this time around as I only lost a pretty small piece of my stack (the piece on the right).

 

First fold (gnarly!):

GDDlT11.jpg

 

Drawn out a bit and "squared":

JbEKeDt.jpg

 

I lost my handle while doing fold #2, which is embarrassingly early, and found myself liking it better without a handle for those early stages, as it allows quickly rotating the billet into different orientations for squaring purposes, which is limited to only one axis when using a handle.

 

The big drawback is that it's quite a bit harder to do the first 90 degrees of the fold using tongs, but with a billet this size, the post vise easily solves this. I'm sorry I don't have any photos to illustrate my point: when things get a little bit tenser for me I just have to focus on the work and forget the camera.

 

0A8xgH3.jpg

 

This all went a bit faster than last time (I think maybe about 30 minutes per fold?). 

 

I decided to stop after fold #3, and water quenched the billet (!)
 

hIDUQGj.jpg

 

Water quenching several times during the foundation forging was an advice given to me by a well known smith [edit from the future: don't do this, it might work for them, but everyone seems to agree that it is not a good idea and likely contributed to surface cracking issues later on]. The idea is to give an opportunity for trapped garbage to escape on the next forge weld (though normally I would do so right after hot cutting, and before closing the fold). I've done this on the first billet and that seemed to work out very well (I also took the risk of doing it late at the kobuse stage to deal with trapped flux, but that felt like last resort).

 

Current weight is 1.16kg, so around 10% loss so far.

 

zE5EwqS.jpg

 

Carbon content still looks comfortably above 1%, as far as my highly tuned spark pattern matching senses are concerned :ph34r:

 

Edited by Francis Gastellu
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I don't pretend to know a lot about the traditional methods of Japanese smiths, but I do know that rice straw is much higher in free silica than other grass straw, which contributes to a fluxing effect.   Between that and the extra carbon for insurance purposes (you can have severe oxidation in a charcoal forge if your blast is too high and/or the charcoal isn't deep enough), it seems to be just another sort of flux. 

 

Old American blacksmithing texts recommend using  all sorts of odd things as flux.  Salt, glass, sand, and in one instance, ground up mud dauber (a type of wasp) nests. These are made of sandy clay, and, for wrought iron, they do indeed work!  Clay itself is high in silica, sand IS silica, so is glass.  Salt works by turning into an acid that removes scale.  

 

Looking great so far. 

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1 hour ago, Alan Longmire said:

I don't pretend to know a lot about the traditional methods of Japanese smiths, but I do know that rice straw is much higher in free silica than other grass straw, which contributes to a fluxing effect.   Between that and the extra carbon for insurance purposes (you can have severe oxidation in a charcoal forge if your blast is too high and/or the charcoal isn't deep enough), it seems to be just another sort of flux. 

 

Thank you Alan, this make sense and shows my lack of familiarity with charcoal forges. It'll be interesting to see what happens with the second billet. I might end up wasting some material but I need to see the effect of those variables for myself... right now I feel like I am cargo-culting this part of the process a little bit, so to speak.

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Some progress on this billet today.

 

Just before cutting for weld #4:

a8zxWc7.jpg

 

Before cutting for weld #5:

N412nk1.jpg

 

And just before weld #6:

Qq8YPRv.jpg

 

Pretty gnarly on the side of the handle... previous cut wasn't too well centered. I still struggle with evenly dividing billets on the fly. 

 

I'm at 0.95kg, so it looks like I'm averaging ~5% of loss per cut/fold/weld operation.

 

vES2Zz5.jpg

 

xuGjoBT.jpg

 

I want to do at the very least a couple more welds before kobuse, but so far so good.

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C'est tres bon Monsieur.

 

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“So I'm lightin' out for the territory, ahead of the scared and the weak and the mean spirited, because Aunt Sally is fixin’ to adopt me and civilize me, and I can't stand it. I've been there before.”

The only bad experience is the one from which you learn nothing.  

 

Josh

http://www.dosgatosdesignsllc.com/#!

https://www.youtube.com/channel/UCdJMFMqnbLYqv965xd64vYg

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