San Mai questions regarding interesting and abstract compositions

[SinePari]

While I understand the basics of the art I have questions surrounding the more abstract outside layers like wire rope, barbed wire, chainsaw/bike chain...

What is the material thickness of the core when you make the initial lamination?

Do you laminate the outside layer to the core when both the core and outside layer are relatively thick, or do you get more dynamic (end result) aesthetics when you vary the thickness of one or the other?

I have some of the same inquiries when it comes to the length/s of the laminated materials....

When it comes to the outside layer of these abstract/interesting outside layers, are your laminations end to end or do you let the core material extend past the outside lamination?



I've seen some beautiful work coming out of this forum and I'm trying to reverse engineer the examples to answer these questions. I figure I'd ask if there were any deliberate methods out there that people abide by, or if there were secrets someone would be willing to share. As with any question I've asked in past threads, I appreciate any and all input, conversation, examples, or helpful hints.

 

[SinePari]

Some notable examples of San Mai that I believe are more centered, allowing the core material to extend past the abstract layer....


Salem Straub's 52100/Cable San Mai Bowie; example of how the core seems to extend past the sammich layer....

Hellize's Post-apocalyptic barb'd wire beauty; what I think to be an example of adding the lamination layer while the core material is thicker than the sammich layer... Again, it might be the choice of material but the end result here looks like the cross section was drawn out more in order to produce a larger intricate design...

I don't know if there is a deliberate method in these two blades, but I really find each presentation to be quite elegant... Salem's blade gives a sort of visual "Hamon", while Hellize's blade seems to really sensationalize the outside layer by manipulating the layering medium...


They definitely serve as examples to further the understanding of my question...

 

[Salem Straub]

Well, first of all, I'm glad you like that knife, and thanks for posting it. It was a very difficult knife to etch/polish and then photograph, indeed a lot more like a hamon blade than anything. The cable was folded until the watering was quite subtle, couldn't really treat it like conventional damascus...

On that, I just made a long billet of cable mascus, folded maybe four times- that's enough to mostly wipe out the familiar cable pattern. I then forged a 52100 bar half as long, but of matching thickness and width. I cut the cable bar in half, then stacked the 52100 bar in between the two cable bars. With everything ground clean, all three bars were probably a heavy 1/8" thick apiece.
I tack welded, then forge welded up and drew it out to 1/4" thick or so, with a point and tang forged on as if it was a normal bar. Carefully, at a yellow heat for the profile forging. Try to forge your bevels symmetrically (similar amount of forging on both sides, rather than more on one side and then having to bend the cross section correct, which is fine with monosteel.)
It's been a while since that knife, don't remember if I check etched while grinding, but that's a good idea. Anyway, as I recall just flat grinding the bevels and profiling as normal took it to that finished look with the core placement.
It's not too tough, get into it and your first one will probably be fine- if not, try again and success should soon follow.

 

[Bill Burke]

you can use material that is equal in thickness or the core can be thinner or thicker that the sides. it takes very good forging practices to keep the core centered so that an equal amount shows from side to side and end to end. I use pieces that are equal in length and width. the best patterns come from they forging of the blade so I like to use at 1/4 inch thick pieces. too much heat will decarburize the core and cause a bright crystalline structure between the core and sides. forge it too thin and the time at welding forging temps will give you fits. leave it too thick and you will end up with a lot of core showing and not much of the outside layer showing.. you can use a nickel shim between the sides and core to retard the decarb but you will loose some of the cool effect that you get at the transition. if you use the shim you can sue a thinner core so more of the outer layer will show.

here are a couple that I have made over the years.

52100 and 416

wraught iron and tamahagane.

stainless/nickel Damascus with SG2 stainless core.

 

[SinePari]

Thank you both for the priceless tips!

I'm going to attempt this tonight with some rail road track steel I drew out the other night... I understand that it's basically 1084 with high levels of manganese. I'm planing on the outside layer being wire rope...


Mr. Burke, I don't have any nickel shims on hand, but I do have some high nickel content bandsaw blades. Would that suffice as a stand in? Lucky for me the gent at my local steel distributor is a fellow smith with decades of experience and is confident on it's composition being L6. All I know is that it's a PIA to move even under my flypress...

 

[Bill Burke]

nope wont work. if you have cable with high carbon the carbon migration won't be as severe as it is with low or no carbon sides. the bandsaw blade is probably 15n20 not L6

 

[Salem Straub]

It could end up looking really cool, though... I've seen some 5 layer blades using 51n20 between the core and sides that looked great.
BTW I've seen all those knives before Bill, but I gotta say again... superb work!

 

[SinePari]

nope wont work. if you have cable with high carbon the carbon migration won't be as severe as it is with low or no carbon sides. the bandsaw blade is probably 15n20 not L6

Rgr that. That was my presumption as well. I need to see if said smith will go halfzees with me to send it in for analysis because it's abundant, priced as scrap, and that place isn't going anywhere soon...

Just for the sake of added interest (***I prep'd and tacked the billet before reading) I'm going to throw the 15n20 between the cable and core. If anything it should delineate the core from the cable ... Might also make it easier when it comes to making sure I'm keeping the material uniform on each side.

If it's worthy of becoming a blade, I'll post up the billet for critique. I will definitely keep in mind the problems you mentioned earlier about differential size causing headaches. I'll layer the 15n20 on the core first, then forge weld the cable layer.... Should make for an interesting first attempt regardless...

 

[SinePari]

It could end up looking really cool, though... I've seen some 5 layer blades using 51n20 between the core and sides that looked great.
BTW I've seen all those knives before Bill, but I gotta say again... superb work!

I'm lucky to get attention from you both.

You both helped me out immensely on my grinder... Your site's information along with Mr. Burke keeping me from zapping myself, finally got my GIB running like a champ!

 

[Gting]

Do we have a billet yet?

 

[DukeHarley]

you can use material that is equal in thickness or the core can be thinner or thicker that the sides. it takes very good forging practices to keep the core centered so that an equal amount shows from side to side and end to end. I use pieces that are equal in length and width. the best patterns come from they forging of the blade so I like to use at 1/4 inch thick pieces. too much heat will decarburize the core and cause a bright crystalline structure between the core and sides. forge it too thin and the time at welding forging temps will give you fits. leave it too thick and you will end up with a lot of core showing and not much of the outside layer showing.. you can use a nickel shim between the sides and core to retard the decarb but you will loose some of the cool effect that you get at the transition. if you use the shim you can sue a thinner core so more of the outer layer will show.

here are a couple that I have made over the years.

52100 and 416

wraught iron and tamahagane.

stainless/nickel Damascus with SG2 stainless core.

These are absolutely breath taking examples Bill.

 

[Bill Burke]

These are absolutely breath taking examples Bill.

Thank you sir.