First San Mai ... some issues.

H

HellFire Blades

Joined
Aug 29, 2016
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Seeing how this is my first post I'll preface it with a little intro.

This is the third knife I've ever made. It's my first attempt at San Mai. It's also my first time free hand grinding on my own grinder (cheapo Craftsman 2x42) so, be gentle :o If I didn't read it here while lurking, I don't know it. And what I've read is limited. So... definitely "noob" status.

Blade is my attempt at a San Mai pocket cleaver. 1095 core with 15N20 cladding. My first attempt at forge welding. Simply forge welded it all together (maybe) by hand using thin layers of each resulting in just under a .187 "billet" of sorts. Then cut and ground the blade in a stock removal style from there instead of hammering it to shape in hopes I wouldn't screw up the core location. Questions are:

1: While attempting to drill pin holes, I could NOT get one of the holes to go through. I burned up two drill bits trying. It would go through the outer 15N20 layer with no issue but stop, squeal and smoke when it hit, what I'm guessing, was the 1095 core. Tried grinding from both sides, no dice. Switched drilling location slightly, same issue. (You can kind of see in the pictures below but forgot to get a spot specific photo. Sorry, Fail.) The other pin hole had some slight resistance but punched through with some minor muscle. This spot just wouldn't give. Did I somehow manage to partially harden the center? Blade hasn't been quenched, just forge welded and normalized. I don't have vermiculite or anything to really do much of an anneal. The bits I have are allegedly for metal and have never given me an issue drilling previous knives and other metals.

2: Once ground enough to show the differing layers of steel, a visible layering/line was evident. Is this normal or delamination? I ran my fingernail across it and it didn't catch but it was a clearly visible line. (No, sorry again... I took a short video on my phone but no picture. Maybe tomorrow after work I can update)

3: In my haste to see if I had succeeded in creating the epic san mai goodness I love, I etched the blade (1 to 1 FC and distilled water... very concentrated) hoping the 1095 would turn a nice black and the 15N20 would stay silver. I'm not expecting the extreme difference like in a stainless San Mai but, just wanted to see "how I did" if you will. Instead of the 15N20 staying silver, it etched a dark grey. The exact same color as the 1095 turned if not darker. Now, I'm assuming (hoping) this is due to the blade not being heat treated yet?? Should I expect this to be the end result color wise? Dilute the etch? Longer? (Yes... I do have a picture of this part)




Sorry for the long multi-part post. Any help is greatly appreciated. I did a search for the questions and came up empty. I'll try to upload with better pictures tomorrow.

Thanks in advance.
 
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Weird, my 15n20 all was stays silver when I etch. This is the case befor and after heat treat. Are you sure you have 15n20? Where did you get it from?

As to drilling the tang I hate to pass this advice along especaly to a newbe but it does work but be careful. You can heat a tang red hot and drill through it like butter while it's red hot. Don't dilly doddle just drill the hole and do it quick. If the tang cools off befor you get all the way through then reheat the tang and finish the hole. Make sure you don't over heat the drill tip, hence no doddling.
 
You're either work hardening or heat hardening the steel. I had that problem a LOT on my first few knives. I had to drill one with a dremel and a diamond tipped bit. It's not easy, but it will get you through. It may be the only way now that you've hardened that spot. When drilling knife steel, you want a slow speed, some sort of cutting lube, and slow feed. Don't push hard and try to go fast. Once I learned to slow down my drill speed and feed speed, all was well. I've now drilled hundreds of holes with no problem. You've probably also trashed the drill bit. You might be able to sharpen that one or get a new one and try again. But if you work hardened it like I did, you're hosed. Try JT's suggestion or get a diamond dremel bit.

Edit: The other option is a carbide bit, but they're expensive and fragile. By the way, the blade looks great!
 
Oh man, I've found myself hot-drilling holes a few times. I am usually in a terrible state when reduced to that! I'd try sharpening that bit, or using a brand new one, drill very slow (100 rpm or even hand-crank the quill if you can) with a high feed rate to break through that work-hardened crust in the bottom of the hole. It's worked for me many times, but is not at all guaranteed either. 1095 needs to be sub-critical annealed if you want to drill it after forging. That means, heat it up to an even dull red (still magnetic) air cool to black, oil quench, repeat twice more. That'll get it as soft as can be without the use of a kiln. What you have now is probably a partially air-hardened blade/core. 1% carbon steels are a PITA for this.

If I had that problem right now I'd go put it in the mill and use a carbide end mill to finish drilling. That works well if you have it.

It does look welded to me.
 
No advice but congrats on starting! You'll learn so much and then you'll be dispensing advice.

Sent from my ONEPLUS A3000 using Tapatalk
 
Is there a chance that the light color line is all that's left of the 15n20? As for drilling the tang you just need a good drill bit or to anneal the tang as Salem mentioned. Looks pretty good though!
 
JTknives said:
Weird, my 15n20 all was stays silver when I etch. This is the case befor and after heat treat. Are you sure you have 15n20? Where did you get it from?
Click to expand...

Both the 15N20 and 1095 are from Aldo at NJ steel baron. I have more. I'll cut off a test piece and dip that and see if there's a difference. I dipped a rag in FC and ran it along the edge to check and make sure the core was centered after forge welding and the 1095 turned a solid black line and the 15N20 only very slightly greyed. Not sure why the whole blade etched this time.

Alfazulu,
Thanks. I'm learning slowly but enjoying the trip. Definitely looking forward to working with better equipment but I'm making due for now.

Sadly I don't have a mill and couldn't find a carbide drill bit at Home Depot or harbor freight for the life of me. I'll see if I can dig one up and retry. If not I'll get another metal bit and try to spot heat it with a propane torch. Assuming that should do it? I tried to Dremel through it with a pointed carbide bit but pretty much had zero effect. Granted it's an old and well used bit.

Matt R,
I tested the core location with ferric and still had a considerable amount of 15N20 on either side. It's my first attempt freehand grinding a blade, also my first time flat grinding, but the 1095 was perfectly centered and there was still a decent amount of 15N20 after I ground it flat. I only heated it three times and didn't really work it at all past welding it up. That being said, anything is possible. I'll try to get better pictures to give a better representation.

Thanks for the input everyone!!
 
You can buy the diamond Dremel bits at Home Depot/Lowe's, and they will get you through. I've even used them on M2 at 64Hrc. They aren't cheap at around $15, but it's better than more time wasted.
 
Go to ace hardware and buy an Artu bit...I used this to drill through hardened cruforgeV...follow the instructions and use cutting lube.


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HellFire Blades said:
Both the 15N20 and 1095 are from Aldo at NJ steel baron. I have more. I'll cut off a test piece and dip that and see if there's a difference. I dipped a rag in FC and ran it along the edge to check and make sure the core was centered after forge welding and the 1095 turned a solid black line and the 15N20 only very slightly greyed. Not sure why the whole blade etched this time.

Alfazulu,
Thanks. I'm learning slowly but enjoying the trip. Definitely looking forward to working with better equipment but I'm making due for now.

Sadly I don't have a mill and couldn't find a carbide drill bit at Home Depot or harbor freight for the life of me. I'll see if I can dig one up and retry. If not I'll get another metal bit and try to spot heat it with a propane torch. Assuming that should do it? I tried to Dremel through it with a pointed carbide bit but pretty much had zero effect. Granted it's an old and well used bit.

Matt R,
I tested the core location with ferric and still had a considerable amount of 15N20 on either side. It's my first attempt freehand grinding a blade, also my first time flat grinding, but the 1095 was perfectly centered and there was still a decent amount of 15N20 after I ground it flat. I only heated it three times and didn't really work it at all past welding it up. That being said, anything is possible. I'll try to get better pictures to give a better representation.

Thanks for the input everyone!!
Click to expand...


check out amazon 'carbide end mill' Most of these are slot drills so will be able to drill a hole unlike a true end mill. Ive used solid 1/8th inch ones in my drill press to drill through hardened carbon steel (rc60~) goes through like butter. I run my drill press at maximum speed and just use light pressure and go slowly. For larger bits you might want to back off the speed a little, but using high speed is effective. (i have found even after normalising steel to be a pain to drill so use these on hardened and normalised steel as well). :D
 
Alfazulu said:
You can buy the diamond Dremel bits at Home Depot/Lowe's, and they will get you through. I've even used them on M2 at 64Hrc. They aren't cheap at around $15, but it's better than more time wasted.
Click to expand...

I use this on M35 at 67Hrc , and is much faster than diamond and are very cheap :thumbup:

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Fair warning, this will be long and loaded with pictures.

So, tonight I returned to the shop after work to try to fix and finish this blade. To save some people some reading... it didn't go well at all. Details are as follows:

1: I could not find a carbide drill bit under 1/4 inch (was looking for 3/16) at Home Depot. So, I bought two new cobalt drill bits. I also bought a diamond tip dremel and a carbide dremel tool. And, to spot treat, I even forked over the cash on a push button propane torch to spot heat the drill area. It didn't work... any of it. I must have created adamantium because the dremel made zero progress. The new drill bit did nothing. I heated the spot till it was light orange hot and all it did was make the bit squeel and then start to glow. Put the new bit in, heated it even hotter, slowed the drill press more and same thing, just got hot, squealed, smoked, and made no progress. I even tried to heat it and use the diamond tip dremel piece and all that did was make it glow orange and ruin it. No hole.

2: I accepted defeat with the hole and figured I have made a deep enough socket on both sides to put partial pins in and epoxy the piss out of the handle. I had already normalized the blade prior to grinding so I went right for gold and heated it up then quenched it using my forge. Much much faster than using the giant pottery kiln that currently acts as my heat treat oven. (still unused for anything more than a test fire) Blade hardened nicely. File skated right across no issues. That said, the weird little line I thought might be delamination that I couldn't catch with my fingernail... popped right up and delaminated in the quench.



Hoping it was a small spot I ground the little lifted portion away hoping to find better welded steel a bit higher up the bevel. Initially this worked until I tried to grind the last little bit of the delam off and it rolled up into a little bump and grabbed hold of my belt (3M Gator grit) and yanked the blade from my hands tossing it into the workbench, back into the grinder and onto the floor. I reversed and attempted to clean it all up but it was evident that the weld just wasn't there so... I quit. That's the problem with trying to forge weld in the middle of the Florida sun I guess. Can't really see the color of the steel.



3: After two consecutive fails I figured I'd have another go at etching the blade to see if I was just having an off night last night. I etched the blade again with an identical even etch of darkish grey on both the 15N20 and the 1095. Matching colors. So, I went to the original bars of both, ground them clean and submerged them in my concentrated (1 to 1) mix of Ferric. After five minutes I pulled them out and they were both the same dull grey.



So, I took a piece of 1095 from a different vendor and submerged that in my brand new unopened bottle of straight ferric chloride. I let the piece sit in the bottle for 12 minutes. Removed it and it was... the same dull grey color as the other two. So... one last try I ground clean a piece of scrap damascus (1095 and 15N20) I got from a friend and dropped it into the pure FC bottle for ten minutes. Fished it out only to find a slightly dull grey color permeating the pattern and barely making it visible. Long story short... Something ain't right with the FC. I'll try a friend's bottle this weekend and see if there's a difference. But I'm pretty sure mine is bogus. (the original pictures posted make the blade look much darker than it actually was because it was wet. Once dry it was a dull ugly grey the same as the pictures posted here)

So... that cleaver got tossed into the newly deemed F*%k Up bucket and I ground out knife number 4 to make me feel better. I also cleaned and welded up another bar to hopefully successfully weld into San Mai this weekend. We shall see.



Thanks again to everyone who provided suggestions. It was an expensive failure in both money and especially time. About $125 total wrapped up in the failed cleaver buying everything I needed to make it only to have it get dumped as a fail. Live and learn I guess.
 
Hang in there man, as a fellow newbie, I sympathize with you! Learning the hard way sucks, but when you're old and crusty you'll have some good stories for the young 'uns.
 
My 15n20 from Aldo also etches rather dark. Try a more dilute solution, I did that and started getting a more light grey from it. I prefer to use plain nickel now for contrast but 15n20 still works fine, just etch really slow and it will work out, also try bringing it to a mirror polish before etch, that might help a bit
 
Yep, try a 4 parts water, 1 part FC solution for your etch, and let it etch longer. I think your solution is so strong it's just blowing right by the resistance of the 15N20 and etching it as well.

Also, get yourself a bucket of vermiculite from Menards/Home Depot and use it to anneal your blades. Make sure you have a lid on the bucket, it will work better.
 
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