Stainless San Mai and Cleaning Pitting w/out a proper grinder

[NeilJBorja]

I have a bad habit of starting lots of projects and being slow to finish projects.

TLDR:

How do I remove deep pitting on a forged billet without a proper 2x72? Right now my current plan is either an eternity of filing or maybe roughing things out with an angle grinder and then filing things flat. I don't want to use a mill or surface grinder because it's only about 1/8" including all the scale, so probably 3/32" without scale at the thickest, and it's not perfectly flat so I'm afraid a mill or surface grinder would take off too much material to get things flat. I buzzed off some of the scale with a bench grinder, but I'm not sure that's a viable solution to get everything out.

Fluff:

My university's forge just got an updated space, and along with it, a forge press. I got to demo the forge press for some sponsors and Materials Science professors. One of the sponsors/professors said he was gonna try to invite Bob Kramer to visit our blacksmithing shop
I made some wrought-O1 san mai, but forgot it in the fire and it turned into a modern art sculpture. I was sharing the fire with someone but I guess neither of us noticed it fall in because the wrought didn't spark very much, even when it was melting.

After reading up on stainless san mai, I decided to use said forge press to make a billet from scraps I had. Materials weren't ideal, but I had 316 and O1 on hand. I asked a friend to weld the sides shut and started with a 1" x 1.5" billet of 2 1/4" pieces of 316 and 1/8" piece of O1. I drew it out to a billet roughly 7~8 inches long, 1" wide, and maybe about 1/8" thick.

Profile grinding seemed pretty promising, though I hope I'll still have some stainless left after I remove the pitting.

 

[Bill Burke]

soaking in sodium bisulfate will remove the scale. pits will either need to be forged out or ground/filed out.

 

[Don Hanson III]

What Bill said, or angle grinder.

 

[12345678910]

See the photos of the filing jig in my standard reply


You can put an angle grinder on it instead of a file.


Hard wheels to go through the scale, flap discs to rough bevel.



The university needs a 2x72"
See if you can get the art sculpture, or repair, or support staff for machinist / welding to do it.
Try talking to they guy that wants to invite Bob Kramer.

 

[NeilJBorja]

Thanks for the input guys. Count, my university shop apparently has a Bader on the way, so I guess it's just a matter of waiting. Angle grinder got the worst of the pitting out of the steel, then I filed the ricasso and handle area as flat as I could (I knew the 316 would be a bear to work, but I didn't realize it would clog up files so quickly), then hit it with some Dykem and flat sanded what I could. My cheap AO 120 grit is moving at a snail's pace, so I just bought 25 sheets of wet/dry silicon carbide, so hopefully that'll do the trick. I figure the O1 core is thin and off center enough that it'd be wiser to chase it while filing the bevels instead of aiming for dead center of the stock.

Found it interesting that you can see the core very clearly when you draw file the edge, but the distinction seems to disappear when you use sandpaper.

Never worked stock this thin before where you could accidentally put a bend into it so easily (but with the corollary that you can straighten it pretty easily too).

I guess since I didn't flatten the steel completely on my first knife, it's only appropriate that I try to actually get it flat to eliminate gaps (and maybe try for dovetailed bolsters) this time around.

 

[NeilJBorja]

Burned through half a dozen belts cutting through 316's low machinability with a little HF 1x30 belt sander. Still fighting with fundamentals like shadows and gaps on my pins and glue gaps, though I think a lot of that is due to the 316 warping and me not taking the time to flatten the 316 properly.

 

[NeilJBorja]

Just to put some closure on this knife, got it all sharpened up. Unfortunately it's a gift, so I won't be able to see how it holds up over time. I've got gaps you could drive a truck through, so it looks like I still need to work on my fundamentals, or at least work with softer materials until I get my hands on a real grinder. The O1 core was too thin to start with, so you can barely see the transition between the 316 and the O1, though a patina over time should take care of that.