Electrolyte etching and blade finish, strange effect

[pwheeler]

I got a personalizer plus recently, and I noticed on the first few blades that the area that had gotten electrolyte on it became brighter/ more silver. These blades are S30V, hand sanded to 400 grit.

One of the things I've been fighting in the finishing of these, besides keeping my sanity, is that on my final grit (lengthwise), there is a tendency to develop kind of a darker stripe down the middle of the blade. It's almost slightly brownish in the right light, whereas the edges stay more silver. I've tried wet sanding, doing my final passes with very light pressure and fresh paper, and a few other tricks, but haven't quite been able to beat the dark streaks. One of those things you can only see in the right light/angle, but still bothers me.

At first I was distressed by the silver blotch from the electrolyte, but I found if I wipe the whole blade with it for a second, the whole thing becomes nice and even, and in fact it eliminates the dark streaks and looks great. The question is, has anyone else seen this effect? What's going on? Is there anything else I could wipe it down with besides my etching fluid? Salt water maybe? Acetone and soap/water have no effect.

 

[DAMNENG]

First let me say I don't use S30V, but I do use a lot of 154CM. I have experienced the shinny spot on the blade, but only around the area of the logo etch. This can be reduced by using a fairly dry pad on the etcher. This helps keep the electrolyte from seeping under the stensil.

As for the brown streak. I'm guessing it could be caused by scratches left from a coarser belt running parallel to your finish stroke. I have experienced a similar affect showing up as a haze. Looking at the streak under a magnifier the scratches show up but can't be seen with the bare eye.

Hope this helps.


Jim A.

 

[pwheeler]

I actually think it's the opposite, the S30V dulls the grit so fast, the center of the paper gets worn smoother after just a couple strokes, the edges of the paper don't see as much contact so they cut more and deeper. The end result is that the center of the blade is finished finer than the edges. Like I said, I can mitigate it by finishing up with some light strokes to the paper doesn't get dulled and loaded so much. But the coloration difference I don't get, never saw it with AEB, and perhaps a little with 440C but not as much.

 

[jdm61]

I had what appeared to be "burn through" on a 115W8 sujihiki I did back in 2013. There was a brown spot on the blade opposite the mark and it just wouldn't go away. I had never seen that before and hasn't seen it since. Electricity is some funny stuff.