ladder pattern chatoyance

[jdm61]

i have made a fair bit of ladder damascus over the last 6 or 7 years and with "regular thickness" blades of say anywhere from .174 to .300, I didn't get that "shimmer" until I was well over 300 layers. I have made a knife or two from 180 layer steel and while it looked very nice, it just didn't "pop" like the 400 layer stuff. (I also discovered that for best effect with ladder, you had better plan on forging to general profile before pressing and then stock removing for the bevels so you don't distort the pattern in undesirable ways.) My question is would this apply to very thin steel like for a kitchen knife as the layers are thinner? The couple of thin blades that I have made utilized 350-400 layer steel that I already had made for general use on thicker knives. I just took it down to a thick 1/4 inch or so, pressed carefully and ground away the ridges. Do you have to go that fine for a thin piece of steel?

 

[Stacy E. Apelt - Bladesmith]

Chatoyance is a pattern caused by the light being broken by parallel lines of reelection. It can be a rotating bicycle wheel, a screen door, the lines of crystal growth in a gemstone, or parallel scratches/ridges on a piece of steel.

The more layers the billet has, the more parallel likes are created when you manipulate it into a ladder pattern. I find 500-1000 layers shows the effect very well. For the highest chatoyancy, use plain flat laminations with no twists or other shaping. Cutting the grooves in creates a tighter pattern over forging them in. The closer together the lines are cut in the more scintillation. Etch and finish with a fair bit of topography.

 

[jdm61]

I have the fine 3/16 inch Uncle Al dies which make for a pretty tight ladder. Extreme "topography" is not really a great option on a kitchen knife IMO.

Chatoyance is a pattern caused by the light being broken by parallel lines of reelection. It can be a rotating bicycle wheel, a screen door, the lines of crystal growth in a gemstone, or parallel scratches/ridges on a piece of steel.

The more layers the billet has, the more parallel likes are created when you manipulate it into a ladder pattern. I find 500-1000 layers shows the effect very well. For the highest chatoyancy, use plain flat laminations with no twists or other shaping. Cutting the grooves in creates a tighter pattern over forging them in. The closer together the lines are cut in the more scintillation. Etch and finish with a fair bit of topography.

 

[Stacy E. Apelt - Bladesmith]

The dies are certainly easier, but I have read they move the lines of scintillation a tad apart than cutting the lines in and forging flat. The difference is probably moot.

I agree that severe topography isn't desirable in a kitchen knife, but some amount is needed for high scintillation. It can be pretty low and still get the effect. Each ridge makes a new reflective surface. As the blade moves, the light hits one after another making a moving bar of light called chatoyance. BTW, scintillation is a flash of light caused by the beam striking a reflective moving surface.

I sand the blades down to very smooth and give a light etch. All I do after that is lightly sand with a high grit paper to polish the higher surfaces, which are only a few microns above the lower surfaces.

I want to correct something I said in the last post about using plain flat laminations. What I meant was that things like birds eyes, or twists can mess up the optics of chatoyance. Some patterns seem to really accent it, however.
One style that really looks great as far as chatoyancy is "crazy lace" and similar patterns. It is like a ladder pattern on lacy horizontal striped bars. Damasteel has several pattern that show a lot of chatoyancy. The blades can feel almost slick smooth and still have the glint from the bright steel to form the rolling eye. Hugin is the best for this effect, with Odin's eye showing a fail roll.