View Single Post
  #7  
Old 06-11-2021, 07:55 AM
Ed Caffrey's Avatar
Ed Caffrey Ed Caffrey is offline
Super Moderator
 
Join Date: Jun 2002
Location: Great Falls, Montana, USA
Posts: 4,393
Send a message via AIM to Ed Caffrey Send a message via Yahoo to Ed Caffrey
Now it becomes a process of elimination.... trying to find what is causing the issue where it's happening in the process.

If your ferric is over a year old, or if it is possibly contaminated, then mixing a new batch is a good idea. Just remember to mix it, and let is set overnight before you use it.

I can't be sure of what to say about the cleaner you use.... except to suggest you try the acetone, then windex cleaning. When you say "unprinted paper towel".... is it the white paper towels most folks use? If so, then that is very possibly at least part of the issue. ANY paper towel that I have tried, will leave a film that impedes etching. The ONLY "paper towel" I've found that doesn't leave the film are the blue colored "Scott Shop Towels" paper towels. Clean cotton rags work too.

Sounds like the etch temp is good....and the time too. I typically don't make time the determining factor when etching.... I typically etch until I can feel the topography with a fingertip. That tends to be a shorter length of time for tight patterns like in you pic.... and longer for larger, more open patterns.

Once the etching is complete, the after actions are important too... Neutralizing the etch is imperative. A saturated TSP solution (tri-sodium phosphate), with a few minutes soak. Keep that "dark" or "black" which happens in the lows of the topography is a challenge. Folks try all kinds of things to keep it, but as it comes out of the etch, you want to get rid of that stuff....it is nothing more then sludge, from dissolved steel. If left, it acts like a sponge drawing moisture, and causing rust.

Were it me, and considering the what I see of the damascus in the pic, I would etch it to depth, then after neutralizing, scrub it in clean/soapy water with #0000 steel wool until clean. It should start to show some chatoyance by then, and then would give it a good cleaning/polishing BY HAND with a clean cotton or microfiber cloth, and something like Wenol, or Flitz metal polish. This is not something I often do, but it is effective on tight patterns that have the potential for good chatoyance (such as I see in this piece of Damascus).

I didn't see what the steels where in that damascus, but that can possibly have an impact on the etch too. Most of the time I assume folks are etching/using 1080 or 1084, and 15N20.


__________________
WWW.CAFFREYKNIVES.NET

Caffreyknives@gmail.com

"Every CHOICE has a CONSEQUENCE, and all your CONSEQUENCES are a result of your CHOICES."
Reply With Quote