Last words of advice before I start ruining some 15n20/1080 trying to make San Mai?

JG Custom Metal Works

JG Custom Metal Works

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Nov 27, 2013
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I got some of JTknives' 15n20 in today and I figured I'd try my hand at making some San Mai. I plan on using the 15n20 and 1080 from Kelly Couples. I might use Aldo 1084 if you guys think that might work better.

The plan is to run the pieces through the Wuertz KMG surface grinder first and foremost. Any recommendations as to what grit/finish I should leave on the surface?

As far as flux, I've been reading a decent amount of guys doing clean/dry welds(no flux used) and just making sure the surfaces are ground and clean(of fingerprints, oil, etc.). That would probably be the most convenient for me to do. Borax is the only flux material I have at the moment. What do you guys think?

Finally as far as holding the stack together, is there anyway to get around using a welder? I have an old Lincoln Tombstone AC/DC welder but have never used it and haven't stick welded since shop class in high skrool(15yrs ago). I can make it happen if need be though. I don't have a welding table or anything though.

I'll be heating the small billet in my Atlas Mini Forge. I do not have a hydraulic press or power hammer, so I'll be using a good old hammer and anvil. Any advice on getting the job done using those? I've read decent amount and watched a good amount of instructional videos regarding pattern welding. It's my understanding I want the pieces to be bright yellow(near white) hot, around 2300f. Also that the initial weld should be set with firm but not terribly hard hammer blows.

I know it's obvious I don't have the optimal setup for this operation but I want to do it. I'm not planning on doing a huge billet or anything. Probably a 6"-7" billet. Just enough for a smaller blade. I mainly want to do it to try out the process.

If anyone has some real good instructional videos or articles/guides, I'd greatly appreciate it. Any words of advice or tips would also be greatly appreciated. I'll try and post pics of my epic fail :D
 
I forge welded for about 8 years with no power hammer-mostly damascus but some san mai as well.
I still use borax as a flux-haven't gotten around to trying the dry (or kerosene) methods. With a hand hammer, I was taught to set the welds with light, fast blows rather than whomping on it-that tends to displace the stock and also lets some parts get below welding heat. I would stick weld the corners at least-you can wrap it in iron wire, but it only sorta works, and involves some cleanup and/or dents in the billet if the wire doesn't weld. I gas weld my billets (off the grid, and my generator won't run a welder) and just clamp the billet components in my post vise.
San mai should be an easier start than damascus, at least. You won't have to draw it out (which is really where the power hammer comes in).
Good luck and have fun!
 
You can forge weld these pretty easily with flux or by using kerosene. I prefer to go the kerosene route so I don't have to replace my forge lining after the borax eats it. I have made San Mai in an atlas mini forge using hammer and anvil so that will work fine. If you choose to use kerosene, just make sure you have clean mating surfaces. I don't take mine to a high grit, just knock off scale and rust. If you can't get them tac welded together first, you can wire them together to set the weld. I would recommend finding someone to tac them together.

Using 1080/84 and 15n20 will give you some contrast when you etch, but you are kind of missing the point of San Mai. Most San Mai consists of a hard core and soft jacket. You may want to try with a lower carbon steel for the outer layers. If you are just going for looks I guess it doesn't matter. One thing that looks cool is placing a very thin piece of nickel between the layers. This will give you a bright silver line along the blade where the layers meet.


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I'm looking to do the same. In the future, looking to get my own welding setup, but for now...

If I went to a welder, is there any vocabulary to use so I don't sound any dumber than I am? Left to my own devices, I would say "Can you tack weld this 1084 + 15n20 stack together?"

Also, brettn, when you say "a very thin piece of nickel", do you mean pure nickel, or some alloy?
 
Pure nickel - admiral and some other places sell it. If you go to a welder, just ask them to tac it together. I do mine like a stack of Damascus and tac each corner and then run a bead across all three layers in the middle of each long side. You may want to get them to weld a piece of rebar to one end to use as a handle. Much easier than holding it with tongs in my opinion.


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Just to clarify - if you go the kerosene route, you do that before you put it in the forge ;-)


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brettn said:
You can forge weld these pretty easily with flux or by using kerosene. I prefer to go the kerosene route so I don't have to replace my forge lining after the borax eats it. I have made San Mai in an atlas mini forge using hammer and anvil so that will work fine. If you choose to use kerosene, just make sure you have clean mating surfaces. I don't take mine to a high grit, just knock off scale and rust. If you can't get them tac welded together first, you can wire them together to set the weld. I would recommend finding someone to tac them together.

Using 1080/84 and 15n20 will give you some contrast when you etch, but you are kind of missing the point of San Mai. Most San Mai consists of a hard core and soft jacket. You may want to try with a lower carbon steel for the outer layers. If you are just going for looks I guess it doesn't matter. One thing that looks cool is placing a very thin piece of nickel between the layers. This will give you a bright silver line along the blade where the layers meet.


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Thanks for your response. That goes for everyone else who's responded too.

Could you explain your process for fluxing with kerosene please? I'd really appreciate it.
 
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Geez. Just mig all the way around it, squirt some wd-40 in-between the layers before you close up the welds if that makes you feel better, and weld it.


The only tricky part is time and temp. Very little soak is required with small san-mai billets however. You difficulty is going to be getting an even welding heat the length of the billet with a small venturi forge. Get it yellow (which is hotter than necessary) in low (shade, not dark) light, and smack it.

If it fails, your temps were off. If it's surface ground and clamped tightly and mig'd all around, it'll be practically welded when you pull it out of the forge.


Edit: re-read your post and you've only got a stick welder, that's fine. Weld all the way around it the same. Or tack it, soak in kerosene and do the above. Or tack it, get it red, pour borax on the edges, stick it back in teh forge, and do the above. Any of these methods will work easily.
 
javand said:
Geez. Just mig all the way around it, squirt some wd-40 in-between the layers before you close up the welds if that makes you feel better, and weld it.


The only tricky part is time and temp. Very little soak is required with small san-mai billets however. You difficulty is going to be getting an even welding heat the length of the billet with a small venturi forge. Get it yellow (which is hotter than necessary) in low (shade, not dark) light, and smack it.

If it fails, your temps were off. If it's surface ground and clamped tightly and mig'd all around, it'll be practically welded when you pull it out of the forge.


Edit: re-read your post and you've only got a stick welder, that's fine. Weld all the way around it the same. Or tack it, soak in kerosene and do the above. Or tack it, get it red, pour borax on the edges, stick it back in teh forge, and do the above. Any of these methods will work easily.
Click to expand...

Sometimes it's hard to understand a person's tone through text or online. I'm not really sure what the whole "Geez" comment is about. Is this all information I should know? I've been on here and other forums for years, and I don't see the actual process of making San Mai being discussed here much. Also, I'm not sure what WD-40 is supposed to accomplish so I'm not sure how doing that would make me feel better or worse.

I know when talking to someone who isn't particularly well-versed in the subject matter, it can be a little frustrating. I'm not trying to be difficult by asking too many questions, I just am trying to find my footing with all of this. Please be gentle, it's my first time with san mai. ;) Wait excuse me...Oreo steel, or is it koku-saka now?

Anyway, sorry if I read you wrong. I appreciate your help.

I'm gonna attempt to stick weld my layers together tonight. I might even do a late night run to walmart for some kerosene and give things a go.

For fluxing with kerosene, all I need to do is soak it for a bit before I heat it to set the weld? Sounds so easy, even I can do it. :D

Will update. Thanks guys!
 
AND you don't do it if you have to reflux when the billet is hot!!!!:eek: Borax still has its place.:D
brettn said:
Just to clarify - if you go the kerosene route, you do that before you put it in the forge ;-)


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Click to expand...
 
JG Custom Metal Works said:
Sometimes it's hard to understand a person's tone through text or online. I'm not really sure what the whole "Geez" comment is about. Is this all information I should know? I've been on here and other forums for years, and I don't see the actual process of making San Mai being discussed here much. Also, I'm not sure what WD-40 is supposed to accomplish so I'm not sure how doing that would make me feel better or worse.

I know when talking to someone who isn't particularly well-versed in the subject matter, it can be a little frustrating. I'm not trying to be difficult by asking too many questions, I just am trying to find my footing with all of this. Please be gentle, it's my first time with san mai. ;) Wait excuse me...Oreo steel, or is it koku-saka now?

Anyway, sorry if I read you wrong. I appreciate your help.

I'm gonna attempt to stick weld my layers together tonight. I might even do a late night run to walmart for some kerosene and give things a go.

For fluxing with kerosene, all I need to do is soak it for a bit before I heat it to set the weld? Sounds so easy, even I can do it. :D

Will update. Thanks guys!
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No bud, sorry, I wasn't trying to be snarky or condescending. Just trying to make it clear (which I failed at) that there's no reason to make it more complicated than necessary. Apologies for the misunderstanding. There's about 50 ways to skin this cat, but it's a pretty easy job, as long as you keep it simple. =)


Edit to add: The WD-40 works just like kerosene, parts cleaner, whatever. I say "if it makes you feel better" because most people seem to think of fluxes and similar as glue. The reality is, all you need is a lack of oxygen and nothing (read: semi-clean surfaces) getting in the way to weld. Steel wants to weld, we're just creating an amenable circumstance and coaxing it along. We're not "forcing it together" by hammering on it by any means.


Feel free to pm, email, or call me if you have any troubles.
 
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javand said:
No bud, sorry, I wasn't trying to be snarky or condescending. Just trying to make it clear (which I failed at) that there's no reason to make it more complicated than necessary. Apologies for the misunderstanding. There's about 50 ways to skin this cat, but it's a pretty easy job, as long as you keep it simple. =)


Edit to add: The WD-40 works just like kerosene, parts cleaner, whatever. I say "if it makes you feel better" because most people seem to think of fluxes and similar as glue. The reality is, all you need is a lack of oxygen and nothing (read: semi-clean surfaces) getting in the way to weld. Steel wants to weld, we're just creating an amenable circumstance and coaxing it along. We're not "forcing it together" by hammering on it by any means.


Feel free to pm, email, or call me if you have any troubles.
Click to expand...

It's all good, no worries or need for apologies.

Again, thanks for the help. I'm gonna try and utilize it tomorrow.

Cheers!
 
Not to hijack your thread, but i wanted ask about lower carbon steel mentioned in this reply.

Using 1080/84 and 15n20 will give you some contrast when you etch, but you are kind of missing the point of San Mai. Most San Mai consists of a hard core and soft jacket. You may want to try with a lower carbon steel for the outer layers. If you are just going for looks I guess it doesn't matter. One thing that looks cool is placing a very thin piece of nickel between the layers. This will give you a bright silver line along the blade where the layers meet.

I have some wrought I can use, what other recommendations for lower carbon steel would you guys make, 1018 or 1014 maybe?

Russell
 
I just did a mild/1095 san mai last night. Here's what I did:

I cut 3 equal lengths of inch bar (1/4 for the mild slabs, 1/8 for the center 1095). I cleaned the faces on the grinder (no need to use a fancy surface grinder, we are getting this metal HOT; when we tap it together, a few thou of space between the surfaces is gonna close right up). I stacked and clamped the billet, put a bead down the four corners (6011 from a stick welder) and welded a piece of rebar on for a handle, heated and fluxed with borax (I do all my forge welding in coal when possible, because my firepot doesn't mind flux as much as my gas forge liner). Then I brought it up to welding heat (this is much easier in a coal forge, first because coal gets to welding heat without any troubles or adjustment of gas pressure, and second because you can judge that you are at welding heat when the stock is the same color as the edges of the coal). If you are doing this in gas, look for the surface of the piece to look sort of liquid. I laid it on the anvil and tapped the thing lightly and rapidly down both slabs. I reheated and repeated the light tapping, just to be sure that it was set fully. I took a third and fourth heat and used heavier hammer blows to further blend the weld.

After that, I let it air cool, ground off the sides of the billet (and the handle) and checked my weld around the whole block. it looked good, so I started forging out the blade. Honestly, the whole process is pretty easy. There is no magic or secret formula, just some important things to keep in mind:

1 - Get the scale off the mating surfaces.
2 - Make sure the billet is aligned properly when you weld it up.
3 - Use a handle (fishing for pieces at welding heat with tongs blows).
4 - Use light blows to set and use multiple heats to be sure.
5 - When a drop of anhydrous borax hits your hand at 2300ish F, suck it up.

As to forging the billet post weld, remember that at a given temperature, mild steel is more plastic than high carbon. This means that the side you are hammering on will move a good deal more than the side facing the anvil, so flip the piece often. Also the sides will tend to bulge more than the center. you can correct this to some degree with light blows on the edges, but either way, leave yourself some slop to grind the edges back a bit.

Hope it helps,

Joe
 
I got my billet welded today. Not too bad for not having welded in 16yrs:








BTW, it's nice to have a good friend who's a professional welder. ;)

As far as the mild steel jacket thing is concerned, I'm not worried about "tradition" with this billet. I just wanted to go the easiest route for this first one. My main concern is looks and I got the 15n20 for pretty cheap(JTknives' band saw blades).
 
Using mild jacket is a double edged sword (pardon the pun), it's got advantages and disadvantages. It's easy to straighten because the low carbon outer wont harden, so you can straighten anytime with a hammer or just bending, etc, but it can be pretty wimpy on a knife that see any impact use or general heavy use/abuse, and will deform and take a set.

With a high carbon outer, you can get consistent hardness, and expect pretty similar or the same "performance" as mono steel. Depending on what you make, and what you expect, it's up to you to decide which works best for you. Personally I wouldn't use mild or non-hardenable jackets on one of my slipjoint blades for example, which are usually 0.080-0.100 thick with heavy distal taper, with a thin enough core to see good activity, you end up with an incredibly thin section of hardened steel.
 
JG Custom Metal Works said:
I got my billet welded today. Not too bad for not having welded in 16yrs:








BTW, it's nice to have a good friend who's a professional welder. ;)

As far as the mild steel jacket thing is concerned, I'm not worried about "tradition" with this billet. I just wanted to go the easiest route for this first one. My main concern is looks and I got the 15n20 for pretty cheap(JTknives' band saw blades).
Click to expand...


Welds look fine, but without welding completely around the edges, you'll have to use flux of some type. If you simply weld it completely shut, you won't, and IMO, it's a pretty sure thing as long as you hit your temps. It's what we typically refer to as a "dry weld".
 
javand said:
Welds look fine, but without welding completely around the edges, you'll have to use flux of some type. If you simply weld it completely shut, you won't, and IMO, it's a pretty sure thing as long as you hit your temps. It's what we typically refer to as a "dry weld".
Click to expand...

Oh well. All I need to do to flux with kerosene is soak it a bit before sticking it in the forge, right? If so, It's not a big deal.

I asked him to weld it all the way around but I think there was a communication breakdown somewhere along the line and this is how it came out. In the future, when I'm doing it, I'll probably just weld entirely around it.
 
Yeah, just "soak" it in kerosene for a bit. The only reason to soak of course, being to make sure it thoroughly coats the inside, obviously the metal doesn't absorb the kerosene.
 
If you've welded the billet closed, then you are dry welding. If only tack welding the billet, dip it in kerosene. No need to "soak", it just takes a second. If using kerosene, stick it in the forge and don't move it until it's orange, pull it out and set the welds. It really is that easy, and the Atlas does a fine job of small san-mai.

DO NOT POUR KEROSENE ON HOT METAL!!!
 
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