Bruce McLeish
Well-Known Member
I've finished the initial shaping of a 1095 blade and want to try a hamon. So, how far do I go with the sanding before ht and etch?
..... Just know that the actual line will be lower than the edge of your clay line .......
Make sure you clean the top of your spine off so you dont get a banana warp.
I've finished the initial shaping of a 1095 blade and want to try a hamon. So, how far do I go with the sanding before ht and etch?
I've never tested it but was was told when I first started using clay to clean the top edge of the spine, if you leave a thick coating of clay on the spine the blade will supposedly curl up at the spine during quench and this is how the old Japanese sword Smith's achieved the upward arc in there blades.I cant remember who exactly told me this as it was a long time ago and I looked up to them so I always took the advice to heart .Could be a old myth like pointing your blade at magnetic north after the quench and after normalizing but I've never been brave enough to go against the advice of cleaning off the spine.Can you please explain this statement in a little more detail? Thanks.
I've never tested it but was was told when I first started using clay to clean the top edge of the spine, if you leave a thick coating of clay on the spine the blade will supposedly curl up at the spine during quench ....
So what do you chalk up the point drop to ? I've done a number of edge quenches and never experienced it. And I'm not trying to put out misinformation this is something I was told a long time ago and just made it one of those best practices in my routine just as if you gave me some advice who am I to question it ? I'm the type that if you tell me dont touch the stove it's hot I dont stick my hand on it to try and disprove you.I respectfully have to ask......if you have no real first hand experience with this, then why are we presenting this (mis)information dogmatically as fact?
It is true that SOME steels and SOME quenchants/methods will produce an upward curve to the spine.
But you can't make a general blanket statement to that affect.
The tops of my blade spines are ALWAYS coated with clay thicker than anywhere else on the blade.
I CAN tell you from numerous first hand experiences that long 1075 and w2 blades quenched edge down into parks 50 will actually drop slightly at the tip.....sometimes more than slightly.
A 7" long 1075 blade I'm working on right now underwent 3 quenches (experimenting to get hamon just right). Prior to the first quench, the spine was dead straight across the entire length. There was an 1/8" drop after the first quench. After the third, the entire spine was a continuous sloping drop point with the tip being over 3/8" lower than the spine at the ricasso.
Again meaning no disrespect.....just trying to correct mis-information.
The science behind why certain steels quenched in certain media experience sori or negative sori is far above my pay grade.
...
Tamahagane vs. modern steels is like comparing auto-mechanics to crocheting, and the variable of each are infinite.
John, I have a good amount of data on the metallurgy of positive vs. reverse sori, clay application and the microstructures responsible, but it may require another day trip to Matherton forge to get into it...
Sorry John. I have not studied all of those factors you mentioned, the advice I gave was based 100% on personal experience alone in trying to produce hamons in my simple shop with simple methods. I can HT a knife with a hamon and I have noticed in my little corner of the world that when I place the clay (generic term) at or below half way down the blade I am not happy with my results. When I place the clay line above the center line of the blade I am happy with the results. I guess you can call me more of a learn by doing person.Hi Chris. I just wanted to point out that the above statement is not entirely accurate. There are many variables that can affect where the transition line will end up.
Steel type, clay layout, clay thickness, cross sectional geometry and austenitizing temperature are a few of the key variables to determining what and where hamon will form.
Sorry John. I have not studied all of those factors you mentioned, the advice I gave was based 100% on personal experience alone in trying to produce hamons in my simple shop with simple methods. I can HT a knife with a hamon and I have noticed in my little corner of the world that when I place the clay (generic term) at or below half way down the blade I am not happy with my results. When I place the clay line above the center line of the blade I am happy with the results. I guess you can call me more of a learn by doing person.