Blended grind lines on bevels.

[Jon Kerr]

Hi everyone,

I'm trying to understand how lots of bladesmiths achieve a beautiful random/organic blend between their ground bevel and forge-scale effect towards the spine of the knife. My grind lines are generally very stark between the shiny and black, but lots of makers achieve a blended, wavy/speckled transition.

Are they somehow deliberately driving scale into the surface to achieve this effect? Forging on a scaled up anvil? Or perhaps using a ball peen to create an uneven surface to deliberately disrupt the grind line?

Owen Bush and JLees are the stunning examples below.... along with an example of one of my knives with a very stark but imperfect grind line which doesn't look as good.

Owen Bush:

JLees:

Mine:

 

 

[George N. M.]

John, I am only an occasional knifemaker but it looks to me like a combination of two things.  One, the upper surface has more "topography" and the grinder is just hitting the high points of the upper surface and, two, rather than the edge of the grind line being the intersection of two flat planes the ground surface is curved towards the spine of the knife so that only the high points of the upper, rougher surface are touched by the grinding belt.

I suspect that that area is done by holding the knife by hand against the belt rather than using a jig that keeps a constant angle.

I'd try foughing up a piece of mild steel and then try different techniques to try to get the result you want.  A forged and shaped knife is not a good experimental medium.

"By hammer and hand all arts do stand."

[ranstang94]

I agree with George on all points, I noticed is that their bevels don't seem to be as extreme as the one you showed. I would almost suspect they are doing a "blending" after they put in their primary bevels with the slack part of the grinder... I haven't tried that but I think it would work. Like George said, experiment around a bit... and let me know how it turns out, cause I see some of that style in my future projects...

[Goods]

John, you forging is just to precise, may need to put a couple erratic hammer strikes in them.
You could try using a rounding hammer with well space strikes for you final smoothing. That would give a nice finish, but still vary to thickness slightly. (More questionable advice from a non-knife maker…)

Keep it fun,

David

[Frosty]

Nice blade Jon. I agree with David, your forging has a more refined surface and the very unevenness is what's causing the effect you wish.

Also, ranstang's point about the steepness of your blade's cheeks cutting across the transition between surface topography and homogenous steel is too abrupt to show it off. Is very true.

The zone where the grinding belt is just touching the high points and not the low points is what makes the wavery line between body and cheeks on this type blade. A good model to help you visualize it would be to draw a stair case line and bisect it with another. In an extreme example start the bisecting line at the top of one step and finish it below the steps 20 steps away. Heck, just lay the ruler over the steps is a better visualization. Now change the bisection to 5 steps before dipping below the steps. 

The length of line crossing steps (as forged, blade topography) is determined by the depth of texture and it's angle of crossing. 

Make sense?

Have I made a blade like this? Oh HECK NO! It's a matter of taste fore sure they, look unfinished and very undesirable to me. It's not like  survived a plane crash in a wild jungle somewhere and I needed to hammer out a spear or dart points and knife on a broken axle from the landing gear and sharpen it on a piece of windshield to protect myself from hungry jaguars and hack a path to safety. In that case anything goes but as an artistic statement? Never.

Not saying anyone else must or even should share my sensibilities, only a fool would turn their back on a market over a matter of personal taste.

Frosty The Lucky.

 

[ThomasPowers]

Some of those look rather "rough forged" to start with and then the  grinding was only done on the bevel leaving the rest "as is" .

[Chad J.]

I've been trying that finish on my blacksmith knives and spike knives.   Those seem like they are more suited for that style finish.   It's a bit trickier than I expected but I tend to freehand my grinding. 

[Buzzkill]

Jon, the short answer is that Owen and JLees blades are forged almost entirely to shape - including the bevels - before any grinding.  That means there is a very small angle between the blade surface and the grinding belt when they finish the bevels.  It looks like you left your blade a bit thicker, so in order to remove the needed material you had to use a steeper angle between the blade and the grinding belt.  The effect of that steeper angle is a more defined line at the point where the "brut de forge" portion of the blade meets the ground portion.

[Jon Kerr]

Brilliant advice, thanks so much everyone who took the time to reply!

This makes total sense to me now: Forging close to final shape, including shallow bevels, means the angle between the "brut de forge" section and the ground section is minimal meaning some of the deeper defects show through in a fading transition.

Thanks!

[ThomasPowers]

The goal of the old Neo Tribal Bladesmiths was to do less than 10% stock removal on a blade.  Forge to shape including bevels!