A little discouraging... Your thoughts?

[Gabin -Haraldr- Piedbois 1]

There was recently a discussion about cracks on a French forum I frequent, and from what I could understand the best way to avoid them with water hardening is to let 2-3mm with a rounded, polished "edge" then finish the grinding after that.
That's an advice given by Achim Wirtz if his name rings any bells

[SBranson 2]

Mat,

Thanks for posting this experiment..lots of good advice..lots more experiments..I suspect the spine thickness had a lot to do with your cracks.

 

Stuart,

I have enjoyed the blades you have posted and value your knowledge and experience. Right now until I try a few more quenches ,I disagree ( I am assuming the clayed spine does need to get hot , to non magnetic...but must be relatively thin) . I have found the thin spine to wrinkle due to the edge expansion , at first I thought this was a defect but I think it is good. I have even thought of pre wrinkling the spine. In about a month I will be quenching quite a few blades and hope you will add the colorful graphs again and participate in the discussion.

 

Jan

 

 

Thanks Jan... I think.

 

I'm not sure what you're disagreeing to. I don't make the spine thin nor do I really know what you mean by it wrinkling or pre-wrinkling...

I'm also not sure if, by "colourful", your comments about the graphs are meant to be sarcastic ...

 

Anyway... this is what Bill Burke mentioned to a thread I posted a couple years ago..

 

"Well at the risk of personnel retribution on here!!!

 

 

When I first started using clay and water I broke almost every blade that I did. But being too stupid to give up and succumb to the norm(parks 50) I kept at it. I did get better and was only breaking about two thirds of my blades. Then I went to Japan and watched as some of the best sword/knife makers in the world quenched blades IN WATER. I watched in amazement as orange hot knives were plunged into warm water and swirled around as if the smith were stirring a pot of soup, and i never seen one cracked blade. Sword smiths went from the fire right into cold water and held the screaming blade there until it was cool and again no cracks.

So When I returned Home I started breaking knives again. I broke knives if I austenitzed in a digitally controlled oven and I broke knives if I heated them in salts and I broke knives if I heated them in the forge. I went back to my old ways of interrupting my quench and didn't break as many but still most of them broke. I bought parks 50 and didn't break blades but the hamons where not what I wanted usually ending up very close to the edge. I reflected on what I saw in Japan and what finally dawned on me was that the edge was the only part of the knife that was above critical temp was the edge. I made more knives and put clay on them and heated in the forge with the windows covered and the lights out. checked the edge with a magnet and when it was nonmagnetic went back into the forge long enought o make sure my heat was even and then as fast as I could from the forge into the slack tub and held it there teeth gritted waiting fo the crack. the blade quit screaming What no ping!! over to the grinder for a quick look HOLY SHIT I got a STIFFY. this is cool. do five more as quick as I can slather on the clay and into the forge while it is still wet. heat into the water great I think I'm coming. OK time to do a sword I cant get it into the frorge so I will use my 48 inch paragon. heat into the water __________ping_________________ping ___PING pingpingpingpingping ping. It cracked almost every half inch for the entire length of the blade. SHIT. Now what the F*&^%. Oh dumb as the whole blade was at temp. duhh.

Anyway the purpose of this long drawn out story is to try and convey to you the bullshit that I put myself through and to let you know that I've done this enough to have some small idea of what I'm talking about and not just relaying information that I have heard or read somewhere.

 

 

So what I have learned. put a very thin wash of clay over the entire blade. put the clay on the back no more than 1/8th of an inch thick. while letting the edge soak at temp is importtant keeping the spine below critical is equally so, so you have to keep putting the blade in and out of the fire. THE MOST IMPORTANT THING IS TO NOT OVER HEAT THE BLADE. even the upper end of the austenitizing range is too hot for a water/brine quench with some steels. if the clay pops of the blade when heating it you didn't have the blade clean enough before putting on the clay dosen't matter if the clay is wet or dry. it is also more prone to cracking and a shitty looking hamon if the clay comes off. Nothing special needs to be done with the water as far as heating or cleaning if your heat and clay is right. I have done twenty five blade now into plain water with no cracks to preasent of course now the next ten will break since I have written all this down."

 

 

Since following his advice I have done 3 tantos, 2 wakizashis and 2 katanas into water without cracking.

I have also added part of Walter Sorrells' method to my process wherein I quench into water then go into 300℉ oil and bring it up to 400℉ and temper for an hour.

Others have found different techniques that work for them...

 

And the reason for water over parks 50 is that to me the hamon is better as is the appearance of the "ha" or edge steel.

 

This was the last one.. my personal katana in W2 for my Iaido practice. It looks better than this in person..

 

Edited March 22, 2014 by SBranson

[Silent Matt 0]

I saw a video of Yoshindo Yoshihara and I'm pretty sure he kept the spine a little cooler than the edge, so that makes sense.

[Jan Ysselstein 105]

Stuart,

Thanks for posting Bills statement again...I have looked at the color diagrams more than most ..I am hoping to use them to help me understand the quenching phenomena ( they are just sitting there). I had some experience with blades saying tick, tick and I thought the spine of the blade was too resistant to the shock of the edge conversion to martensite...I heated the next few blades with only the clayed spine exposed until close to quench time..then heated the edge as well (it was hard to keep the edge much cooler.... and no cracking..the blades were folded 1095e. I did not confirm the spine was non magnetic but it was heated for a long time ( 10 minutes to 15 minutes) and I assume it was. I will have a chance to repeat that process.

The wrinkling is the spine taking on a sine wave form..it is easy to straighten ..a preset would be a little bumping of the edge ( spine) to encourage its wavy formation during the quench.

 

NIce blade , I think I have seen it a while back.

Sorry if I implied the color quenching pics were irrelevant..quite the contrary.

Jan

[Silent Matt 0]

I made two more blades and tried my hand at heat treating one. I left the edge about nickel thick (.050") and normalized it the night before. I used a thinner layer of furnace cement and pulled it further toward the edge this time. I also quenched in brine for three seconds and then into 130* sunflower oil till the activity stopped.

 

No pings, but the hamon stops about halfway down the edge. I think I was a little too cautious on the temperature...

 

I also didn't get any sori, which really takes away from it having any soul. I tried a new pattern with the clay that I'm also not happy with.

 

 

So, the question is: should I run it as is, cut the nakago back to shorten it down, or normalize and re quench?

 

 

Stuart, the furnace cement stayed put this time.

 

 

Thought about it, going to redo the HT.

Edited April 2, 2014 by Silent Matt

[Salem Straub 170]

Normalize and re-quench! It's the only way. Good luck!

 

BTW this is why I bought Parks 50. But Stuart is right on about the differential heating.

Edited April 2, 2014 by Salem Straub

[Kevin Colwell 171]

that is definitely from the temp being too low on part of the blade.

Still, good work. It takes a lot of practice. I used to do stuff like make 4 or 6 similar blades, and just vary one thing with each to see what made differences. Not quite an experiment, but good to help learn.

 

I agree with everyone else about temp control. I use a kiln and have it set at 1450F for 1095, w1, and w2. The blade is actually at about 1445F when I remove it and who knows where but just above critical when I quench into the water.

 

thanks for sharing your experiences.

kc

[Silent Matt 0]

JPH, thank you for the info, I too am rather "frugal"... I'll have to look into the soda quench.

 

 

Kevin, I don't have the resources as of yet to precisely control my temperatures and am finding it hard to get them right in my propane forge. I might have to build a bigger coal forge so I can control it better and get a slightly cooler spine during HT.

[SBranson 2]

Where it worked your blade looks great so you know you can get it right. I wouldn't waste that blade by shortening it. Try again. Also once you have some more length, I'm sure you'll get some sori.

 

Interesting comments about the heat being close to critical for better activity. I just did a few blades in my HT forge, basically set it and soak, and I am noticing that it's harder to get the contrast than the ones I did in an open forge and going by the magnet and by eye. I think the HT forge is a little too hot or maybe it's the difference between water and parks 50.

[Silent Matt 0]

Thanks for the encouragement Stuart, I normalized it last night and might give it a try again tonight.

[Kevin Colwell 171]

I have to use the HT kiln when I make a long sword to get everything right. The blades are too long for me to get both ends up to temp reliably (which is why I know for certain that the temp issue is why the hamon ran off of the blade like that).

 

I have always wondered whether, with shorter blades made from Aldo's 1075 or anything around the eutectic, if it would be better for hamon activity to use the forge and try to keep the spine just below critical and quench. I did that with a number of blades in the 20-25" range and always got good results (unless they were too thin, and they would crack).

 

You did great on the part of that blade that hardened. Either harden it again, or make another. It really doesn't take that long to get a blade ready to heat treat.

 

I have read and spoken to several Japanese sword makers who essentially agreed that they don't fight with the blades too much. if they don't work well (i.e., crack or warp too badly to fix) the sword maker just throws them under the forge and makes another. I have a pile. Every few months I anneal them, cut them up, and make pattern welded stock out of them.

[Miles Hebbard 2]

How about only submersing the bottom 1/3 rd of the blade in your quenchant, that should give you a hard edge and softer spine, less prone to breaking.

[Silent Matt 0]

Miles, not sure if that would effect the hamon or not, might be worth experimenting with.

[James Spurgeon 23]

How about only submersing the bottom 1/3 rd of the blade in your quenchant, that should give you a hard edge and softer spine, less prone to breaking.

 

 

Miles, not sure if that would effect the hamon or not, might be worth experimenting with.

 

Generally referred to as an edge quench... Used by lotsa mastersmiths since it is faster than claying but gives similar results.

Main difference as I understand it, is that the quench line stays mostly straight along the blade at the depth it entered the quenchant.

Keep in mind that you should still have enough quenchant in the container to distribute the heat. But you also have to keep an even depth or you will blur the quench line.

Take a piece of plate or sheet metal and perforate it a bunch so quenchant flows through it, then give it peg legs on each corner so the feet are on the bottom of the tank and the plate sits under the surface at the depth of edge you want to quench. Dunk the tip of your blade until it hits the plate and rock the blade down into the quench till the edge is sitting on the plate, then slowly rock up and down just enough to keep re-dunking the tip if it ends up above the waterline when the blade is down.

That should help keep the quench line sharper. Wayne Goddard suggests using all-thread for the legs to make them height adjustable...

 

Never heard of anyone doing a clay coat AND an edge quench, but I wonder if that would work to have the benefit of the partial quench yet still give a normal looking hamon instead of the straight line??? Questions, questions and more questions...fun ain't it?

James

[Silent Matt 0]

Did the HT over last night and was able to get a decent sori and the hamon will at least travel under the habaki now. I left the edge very thin (around .020") and was kind of worried during quench, but it worked out fine. I held it in the water for four seconds this time.

 

 

I'm having a much harder time trying to get the hamon to come out on this one...

Edited April 4, 2014 by Silent Matt

[Silent Matt 0]

I'm rather uneducated on polishing and bringing out the hamon, but I sanded the blade to 2000 grit paper, then soaked in hot vinegar for five minutes, followed with more 2000 grit, then rubbing compound. I did this five or six times. Please enlighten me on the best way to do this...

Edited April 4, 2014 by Silent Matt

[Silent Matt 0]

I've just been using my finger. What kind of compound do you recommend?

[Miles Hebbard 2]

Jim, the 3 L llama got me going! Pml! I've got a tent shaped piece of plate that covers the Quench tray completely for those mishaps! Helps a lot...

[James Spurgeon 23]

So JPH, can we pre-order book IV?

Edited April 8, 2014 by James Spurgeon

[Miles Hebbard 2]

I second that!

[jaka 1]

JPH where can one access your books? If they're for purchase I'd like to get them. Thanks.

[James Spurgeon 23]

Jaka,

try here:

Book 1 The Complete Bladesmith: Forging Your Way to Perfection

Book 2 Master Bladesmith: Advanced Studies in Steel

Book 3 The Pattern-Welded Blade: Artistry In Iron

As JPH said above, his books tend to build on each other, so it is advisable to buy them in order if you buy em 1 at a time.

James

[Silent Matt 0]

Good thing that first blade cracked or who knows how long it would have taken me to learn all this! Thank you.