[Kinzea L Thompson]

Hi Folks, I have been trying to wrap my head around this for a while, how do you best get chatoyance in a damascus pattern? Is it high layer count and choice of materials, or is it more pattern dependent. As I walked around the blade show in my still euphoric/stupefied state I saw lots of beutiful damascus that seemed almost alive and moving, and some of it seemed to be more than just 2 colors.Any thoughts on this would be welcomed. kinzea l thompson

[Lin Rhea]

Kinzea,
I get the most chatoyance by disrupting the pattern when the layer count is 400 or above and the disruptions being rather close together and sharp. Beyond that I believe it to be affected by the type of finish that is on the steel. Lin

[Kinzea L Thompson]

Lin Rhea, on 16 July 2010 - 07:36 AM, said:

Kinzea,
I get the most chatoyance by disrupting the pattern when the layer count is 400 or above and the disruptions being rather close together and sharp. Beyond that I believe it to be affected by the type of finish that is on the steel. Lin

Hi Lin, Thanks for the helpful info,i had been considering making a set of ladder dies out of triangular bar stock instead of the gear rack dies I now use, with your info on the closeness of the disruptions i will now try to find smaller stock than I had previously considered. Do you think cut in patterns work better for this than pressed in? Thanks again for the help. kinzea

[Lin Rhea]

Kinsea,
I have cut in most of mine, but I know some of the guys press theirs in and get great shimmering effect. I think some of the subtle differences in method may make a difference and who can say what the next guys will look like untill he puts his spin on it? Lin

[Terry L. Vandeventer]

Depending on the effect you are going for, damascus can be finished in different ways. Most makers go for the most contrasting "black & white" by etching then lightly sanding off the tops of the pattern with very fine (2000 grit) sandpaper.

For the shimmering chatoyance, simply rub down the same blade with fine steel wool. I use a plain old SOS Pad between etchings in ferric chloride. The effect is instantaneous. The shimmering happens immediately. You won't have the high-contrast black & white I mentioned above, but in 300-400 layer patterns the effect can be almost holographic. That's all there is to it. If you don't like the shimmering, just etch it again for a minute or two and do the sanding for the 2000 grit traditional finish.

Cheers,

TV

Terry Vandeventer
ABS MS

[Karl B. Andersen]

You guys are forgetting your hammer work.
Use your hand hammers as much as possible when forging your blade to shape, especially when you still have a lot of "meat" left in the steel.
While you still have your beginning bar, even before forging your profile, you can simply go berserk with a ball pein hammer and "upset" the layers as much as possible with a zillion pock marks on the bar.
Then forge the bar back flat on your press or power hammer,. but the upsetting you have just done is still there and will reveal itself in the etch.
There is no chatoyance more predominant or beautiful that that which is forged in.
When forging your blade tapers, really hit your blade sides a LOT! with your hammers while you still have plenty of steel to flatten back out.
Also, don't clean the scale off your blade when forging, but rather let it get all crusted up with scale and forge that in, which also helps to distort the layers.
It'll grind out later.
Just do anything you can to beat that steel into next week!

[Kinzea L Thompson]

Karl B. Andersen, on 18 July 2010 - 02:39 PM, said:

You guys are forgetting your hammer work.
Use your hand hammers as much as possible when forging your blade to shape, especially when you still have a lot of "meat" left in the steel.
While you still have your beginning bar, even before forging your profile, you can simply go berserk with a ball pein hammer and "upset" the layers as much as possible with a zillion pock marks on the bar.
Then forge the bar back flat on your press or power hammer,. but the upsetting you have just done is still there and will reveal itself in the etch.
There is no chatoyance more predominant or beautiful that that which is forged in.
When forging your blade tapers, really hit your blade sides a LOT! with your hammers while you still have plenty of steel to flatten back out.
Also, don't clean the scale off your blade when forging, but rather let it get all crusted up with scale and forge that in, which also helps to distort the layers.
It'll grind out later.
Just do anything you can to beat that steel into next week!

Thanks for the input Terry and Karl, you raise some ideas I hadn't considered. Terry I usually finish my damascus as you describe but I will certainly try the all bright look, might be interesting. Karl I have already been accused of beating my steel into next week, i just wasnt told it was a good thing, seriously, those are some good points about predistortion with the hammer,not getting rid of the scale I might have to work at. Thanks again Kinzea L Thompson

[JD Smith]

Anytime you work with higher layer counts (400+) and utilize patterns that change direction; as in ladder, "W's" or twists, you will get the desired effect. For myself I like to make sure my welds are SUPER clean to ensure there's no crap between layers.Even random patterns at a higher layer count will yield this effect. A record of every hammer strike is told in the finished steel.And lastly the brighter of the steels you work with are the ones that will give the effect, so steels with a higher alloy content Nickel in particular, are the ones you should be using if you wish to maximize the effects.

[Robert Dekelbaum]

If I understand it correctly, what gives this effect in Damascus is having lots of very small surfaces refracting light in different directions. Effectively, it's like a micro-faceting of the layers in the steel when they're exposed by etching. The more you have (to a limit where it washes out), the more movement you'll see in the light as it's played over the steel. Consequently, this is why higher layer counts tend to exhibit this more readily. This also explains why disturbing the pattern by forging or stock removal and reforging can enhance the effect. If you move things around in a higher layered billet, you'll never do so perfectly and so you'll have different layers at different angles where the reach the surface of the steel. When you etch, this allows for what I think of as the first building block of chatoyance in steel. Then, the rubbing with steel wool, or light buffing that some guys do between etches brings out the second level of varied refraction by knocking little teensy micro bevels onto the corners of the highs that will kick light off in yet more directions. this explains both why the steel wool treatment helps as well as why using more nickel bearing steel helps since it etches less readily and leaves more "highs" to refract the light.

I have to run to work, but if I have time I'll see if I can put together a drawing that illustrates what I'm talking about.

-d

[Mike Krall]

I'm hoping you can make the time to do the drawing, Robert.

Mike