CPM-S30V Corrosion

**Ambush Master** · 07-06-2004, 20:15

Bringing a question that I opened via PM up for discussion:

Bill,

I used the T2 CPM-S30V last weekend to cut some meat and now the blade appears to have rust spots and some pitting going on, it has the Bead-Blasted Finish. What can I treat this with other than polishing it with something like Simichrome and a toothbrush or Nev-R-Dull?? Can it be Passivated in something like a Salt Bath or some Chemical Treatment ?? Does this steel tend to do this, that easily ?? I'm coating it with LPS 2 until I know how to properly treat it.

Take care.
Martin

**Bill Harsey** · 07-06-2004, 20:23

How deep is the discoloration? This steel puts us, as makers, in a very interesting place. The stain resistance is pretty good but the material is so hard to finish that we have to use a finish like sandblasting or bead blasting. For added stain resistance Chris and I KG GunKote the Yarborough and Green Beret knife blades. The problem with a sandblast finish is that when the blast medium is recycled it also has pieces of metal in it, these are shot at high pressure back onto the surface of the blade and some imbed there. This can cause a mild electrolysis to happen on the surface, which we read as stain or rust. What kind of rattlesnake did you cut up for chow anyway?

**Bill Harsey** · 07-06-2004, 20:27

Excuse me for not answering the whole question, How the hell do you know what Passivation is? Your the first harsey knife user who's EVER asked about that! Holy crap, you can't take these SF guys anywhere! more to follow.

**Ambush Master** · 07-06-2004, 20:30

Quote:

Originally posted by Bill Harsey
How deep is the discoloration?

What kind of rattlesnake did you cut up for chow anyway?

#1. It appears to be shallow, I'll try a Pencil Eraser and see where it goes.

#2. It was a dead Cow !!

Later,
Martin

**Bill Harsey** · 07-06-2004, 20:31

Passivation for CPM S-30V involves boiling in either hydrachloric or sulphuric acid (need to check, can't remember which) for a period of time. This removes the surface imbedded impurities from any machining process or sandblasting. The result is supposed to be a very clean white surface. This is too dangerous a setup for me to do in this shop. Too many problems associated with using hot acid. (edited because of my usual spelling skills)

**Bill Harsey** · 07-06-2004, 20:41

To answer the last part of your question, no, to this point it doesn't do this (rust) easily. Stuff happens and that's why I'm glad we are having this discussion out in the open here. I'll be following up with the manufacturer in the morning. Hows the actual edge holding up after some use?

**Ambush Master** · 07-06-2004, 21:07

Quote:

Originally posted by Bill Harsey
To answer the last part of your question, no, to this point it doesn't do this (rust) easily. Stuff happens and that's why I'm glad we are having this discussion out in the open here. I'll be following up with the manufacturer in the morning. Hows the actual edge holding up after some use?

The discoloration did not respond to the eraser, I think that this was due to it being down in the grain of the surface (Bead Blasted). I took some Simichrome Polish on a tissue and it went away after some gentle rubbing (AND STAYING AWAY FROM THAT F****** EDGE !!) The tissue turned rather black, so the Jewler's Rouge in the polish did it's job. I think that as I continue this process, I'll "close" the grain and the problem will go away.

As to the edge, WHAT EDGE ?!?!?! I haven't had to touch it, FOR FEAR OF LOOSING WHATEVER I TOUCH IT WITH !!!!

I'll keep ya posted.
Martin

**Roguish Lawyer** · 07-07-2004, 15:54

Quote:

Originally posted by Ambush Master
I used the T2 CPM-S30V last weekend to cut some meat and now the blade appears to have rust spots and some pitting going on, it has the Bead-Blasted Finish. What can I treat this with other than polishing it with something like Simichrome and a toothbrush or Nev-R-Dull??

Martin:

Have you tried wiping the knife off after cutting with it? I am told this works well.

(Ducking now! )

Sacamuelas · 07-07-2004, 16:05

Quote:

Originally posted by Roguish Lawyer
Martin:
Have you tried wiping the knife off after cutting with it? I am told this works well.
(Ducking now! )

Wow, this coming from the guy who loaded his magazines backwards in front of a SF Team Sergeant??? ( not ducking, but laughing)

LOL

Just hacking on ya RL...

Air.177 · 07-07-2004, 17:17

Quote:

Originally posted by Roguish Lawyer
Martin:

Have you tried wiping the knife off after cutting with it? I am told this works well.

(Ducking now! )

I was along with AM on this little outing, and I am still cleaning food particles off of my knives. I suppose that by the end of the evening, none of us were exactly in our,"Right Minds" LOL

**Ambush Master** · 07-07-2004, 17:36

Quote:

Originally posted by Roguish Lawyer
Martin:

Have you tried wiping the knife off after cutting with it? I am told this works well.

(Ducking now! )

Would have thought that in this crowd you would have learned better by now !! You should have thought about it and remembered that I know where you DUCK !!

But yes, I wiped it off, but the combination of blood and salt/seasonings residue combined with body heat and humidity and brought on the staining. It looks good now and I will repeat the Simichrome treatement a couple of more times until the grain tightens up, unless Mr Bill recommends differently !!

Air.177 · 07-07-2004, 17:40

Quote:

Originally posted by Ambush Master
Mr Bill

OHH NOOO!!!!!

SNL anybody? LOL

**Roguish Lawyer** · 07-07-2004, 17:54

Quote:

Originally posted by Air.177
OHH NOOO!!!!!

SNL anybody? LOL

From clandestine surveillance of Mr. Bill's recent visit to The Reaper's lair:

**The Reaper** · 07-07-2004, 18:12

Quote:

Originally posted by Roguish Lawyer
From clandestine surveillance of Mr. Bill's recent visit to The Reaper's lair:

I am unaware of who Mr. Sluggo might be, nor would I be disposed to discuss it, if in fact, I had any knowledge of him.

TR