Thanks for sharing your knowledge on this.
With the electro-anodizing, what happens after a year?
Maybe you have misinterpreted what I wrote ... regarding Spyderco discontinuing the electro-ano process. Nothing really "happens after a year" to electro-ano finishes (at least in my experience of the processes I have used). The electro-ano finish actually "seals" the exterior of the Ti from oxidation and adds durability from the process of growing a TiO (Titanium Oxide) coating on the surface with Titanium nanotube arrays that are the result of anotic oxidation. The thickness of the crystalline layer is what determines the color(s) of light that is/are reflected (the color our eyes perceive/see). I say "perceive" because the surface color does not actually change ..., just the color of the reflected light. A thicker layer of the crystals reflects a differing color than a thin layer. Think about the light from a crystal in sunlight, same principal (does the crystal have color? No, what you see as perceived "color" is the reflected light that escapes the crystal. The reflected light is part of the color spectrum of what the crystal(s) is/are shown (the spectrum of light cast on the surface).
Color anodized aluminum, by contrast, has colorized die added to achieve a color change (different process than for Ti, Niobium, etc.).
Below is a picture (just taken now) of a Millie I put together back in 2013, and also a image of generic examples of crystalline nanotubes under magnification. I electro-anodized this Millie Ti scale in early 2014 and have left-front pocket carried since I finished it. The scratches you see are from a zdp189 Dragonfly that I carry in same pocket as a money-clip and wear from general daily carry. The variable color spectrum you see is the result of variable surface crystalline thickness of the TiO. The bronze area (near the pivot) is thinner than the ice-blue & greens approaching the lanyard tube. The blues & purples near the middle are in-between (TiO crystal thickness vary from thin to thick on this scale based on how I applied the crystal structure across the surface). So, as you can see (in the reflected light) as the crystal thickness increases (from pivot down to the lanyard tube) the reflected color spectrum changes. Electrical input voltage, surface finish (b4 anodization), electrolyte solution, temperature of solution, water content in solution, anodization time, flouride and chloride content in solution, ph level & amount of dissolved oxygen in electrolyte, etc. all play a part in how the crystals are formed, their resultant thickness & configuration results how ultimately light is reflected (a few of the variables when anodizing Titanium).
In general the finish is quite durable. AND, after the finish develops (after some pocket-time and use) I think it nice to re-anodize at a lower voltage to "color-fill" any scratches, etc. This color-fill process can also be done after a stone tumble to produce a more varied finish. I am by no means an expert here and would appreciate anyone's corrections to my understanding of these things). In my mind, like a knife/tool design should be approached on intended use (handle design/ergonomics, blade shape & edge profile, etc.), so should the finish treatment of blade/handle/hardware. I suppose there are some who only car about looks - and that's what makes us all individuals ;-) Regards,
Ti Finish 2-yr Old-1 (image taken today 2016-01-27)
Previous picture (1st page of this thread) was taken 2015-01-10 when the finish was about 1-yr old (images fairly illustrate progressive change in surface appearance over time).
Crystal1
Crystals2
Spey - many thanks for taking time to write the text and produce the graphical illustrations. It is guys like you and several others in this thread that make this a welcoming, friendly, and informational site. Much appreciate it. I guess I was thinking that a screw on the lockbar would be there just like my ZTs.
Actually, there are two screws and an indexing pin securing the lockbar insert to the Ti lockbar. Spyderco just chose to do a relatively clean job of not making the change visible on the outside of the knife (blind tapped fastener holes are an extra level of production finish that is appreciated by me
