Remove Decarb Layer?

I have a SAR 5 that I stripped that apparently had the decarb layer left underneath. That stuff is a hairy byatch!!!!

I have sanded... and sanded.... and sanded.... and sanded.... until I actually changed the thickness of the blade. I put it up in what I thought was a cool dry place. When I went back a month or so later, it had rusted like nothing I have ever seen.

I took it and sanded... and sanded... and sanded some more, until I got worn out. So I put it away again, with the blade well oiled to protect it.

About a moth later, I went back and pulled it out to try again. It had rusted again. Biggest mess I've ever seen. At this point, it is still in the "cool, dry" place, still oiled. I've given up on it. Money wasted, but I've got better things to do with my time. That SAR 5 is a great blade shape, IMO. But this particular one is a lost cause. I am beaten.

I've stripped a couple others and had no issues with decarb. There was some gray stuff underneath that I kinda smoothed out with sandpaper. No problems with it. I've even stripped SR-101 and left it unprotected, in the same place as the SAR 5, and had no issues with rust.

All I can say is, it isn't gray, what I've seen. It looks black, kinda like black mold, but smooth, when I first saw it. Not all over the entire surface, or at least not evenly over the entire surface. But if you strip and see that... you're screwed, IMO. Find a bead blaster and blast the he** out of it.
 
I will second much of what is said above about stripping a SAR5 to find the decarb underneath. I'm pretty sure I was able to watch it rust in open air. I went through a series of sand papers from 60 or 120 grit up to 2000 grit to remove the decarb and polish the blade. I guess I was lucky in that once I got it polished up I have not had any issues with rust. This is one of my primary hunting blades and in all conditions (even going from cold outdoors to warm indoors and back), I have not had any additional rusting. I do keep a very light coat of mineral oil on it when stored, however.

UsBwR0O.jpg
 
Only one I’ve stripped thus far is a tglb. I used Citristrip and a power washer on hot to take the coating right off the entire blade in seconds. But there was decarb underneath it at least whatever it was it started rusting almost before my very eyes from being wet from the pressured water. I swear it was rusting before I got it home that night by the end of the day. I wasted no time sanding the heck out of it to remove it. Also keep it oiled now and before I did not.
 
Do you have pics of blade in question? Post some. Have you stripped yet?
 


Here it is. I had to strip it because there was heavy rusting under the coating after I used a knife to check underneath it. I saw a web pattern which i thought was the decarb and sandpapered it down a few times just to be sure.
 
I tried I wire wheel once. Looks a little better but Didn’t do anything for rust prevention tho.
 
The decarb on my HUCK was ridiculous...rusted overnight.

Screenshot_20171201-144456.png

Nothing a little beadblast/scotchbrite/sandpaper couldn't fix...

Screenshot_20171201-144513.png

~Chip
 
Thanks guys!:) I pulled the handle slabs, I was worried about rust underneath them and I wanted to add liners anyway;).

~Chip
 
That huck came out great brother. Thought it was a different knife with big finish for second . Fantastic work. I’m sure hogs would send you some work if you wanted. Very nice.
 
hlee said:
I will second much of what is said above about stripping a SAR5 to find the decarb underneath. I'm pretty sure I was able to watch it rust in open air. I went through a series of sand papers from 60 or 120 grit up to 2000 grit to remove the decarb and polish the blade. I guess I was lucky in that once I got it polished up I have not had any issues with rust. This is one of my primary hunting blades and in all conditions (even going from cold outdoors to warm indoors and back), I have not had any additional rusting. I do keep a very light coat of mineral oil on it when stored, however.

UsBwR0O.jpg
Click to expand...


That is what I'm talking about when I say true decarb. It it is, it will rust aggressively. Busse seems pretty good about removing the bad, rust aggressive decarb from coated blades before they coat them. If you get one that still has decarb on it, it will take work, and you will know.

On the knives I've stripped, I've only ever had a whisp of orange show up at a talon hole, which I cleaned up a bit, and it never came back. Even when used, and put away with sap, or wet. I don't oil INFI, even the ones I strip.


I've seen a few go rust-busters under coating which would indicate that the decarb was still there, under the coating.


I've never had one do so, coated, stripped, or satin. Ive even swam with them on (lake. Pool, and river, stripped and satin) , and canoed with them, with the only "rust" being a slight smudge near the laser etch and the talon hole, which rubbed off with my thumb, and a cotton swab for the talon hole. Ocean environment may give different results. But I've been on here long enough to see a few weird examples.


But having 1095 and other steels like 5160, sr101, L6, A2, and a few other tool steels, INFI sure is rust free for me.
 
My ash2 was the worst as far as decarb and surface rusting. That is also one I tried a Wire wheel on to remove rust.
It has been on holiday out in Montana for a striptition finish and some liners. Cant wait to get it back when it’s done. I like that knife.
 
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