Composite blade sword!

We used the materials we had at hand to see if the concept was feasible. Also keep in mind that 440c was not used the first time around, it was some stainless steel we had laying around, we aren't even sure what type it is. We plan to use the 440c in a later attempt. We usually have the clamping down and stuff doesn't move like the previous two attempts, but it just didn't go right this time. 440c as much as we understand is the standard for a lot of commercial knife making (if i'm wrong, PLEASE correct me). What would you suggest be a better core? Also what do you mean by a carbon core? Did you mean the carbon we are using on either sides of the steel? Or did you mean steel with higher carbon content? Those carbon pieces are meant to take up some thickness of the blade to make the entirety of the blade lightweight, and to give the thin piece of steel in the middle strength at the same time. Also if were to make the entire blade of carbon fiber, my father and I would be in a bit over our heads, we don't know enough about carbon to make such an attempt.
 
James, we have tested out the strength of the epoxy in the blade. We made a knife before the sword that has been abused repeatedly. It has withstood all attempts to break it and we've been chopping at wood with it and the blade hasn't nicked, nor has the epoxy weakened to any extent that we can visually see, and the carbon has not suffered any damage either. Here is a picture of the knife:
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The blade of the knife is 15" long and 19.5" overall. The width of the blade is 1-5/8" at it's widest, and 15/16" at it's tip.
 
james terrio said:
Sorry to speak out of turn, but...



Why not? Like any other san-mai-type laminate, the middle layer/edge only has to be hard, not necessarily tough. That's the whole point.

Personally, I'd select CPM-3V or Elmax at 58-59Rc (possibly much harder, like 62Rc... that bears some pondering... ) for the core, but all the usual cutlery-grade alloys (stainless or otherwise) can accomplish the high hardness needed for the edge. Toughness and strength will be largely determined by the outer layers. I honestly do not know if CF is up to the task or not.

I'm assuming the steel core has already been heat-treated before laminating. Putting CF and epoxy in a kiln is a terrible idea. Using un-HT'ed steel is just as bad.

I agree that more uniform clamping -- even as simple as putting the whole thing between two boards, and then clamping the assembly* -- is a good idea.

I'm almost dead certain that without mechanical fasteners, it's going to peel apart sooner rather than later. No epoxy I know of can withstand shear/flex forces that will happen when the sword is used to chop and slash, especially when bonding wildly disparate materials. I could be wrong.

Fascinating project. I'm really intrigued to see how it works out.

*EDIT on looking at the pics again, it appears that the assembly was sandwiched between bars of steel during glue-up. That will surely even out the clamping pressure. :thumbup:
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I don't know James, I have a lot of very good swords and none of them are made of 440 C.

I have many laminated blades that use stainless as the skin and carbon steel as the cutting edge to get the best benefits of both materials but I personal would not want it in reverse

Folks can do what you want, but I personally would not own a stainless steel sword , axe or tomahawk made of 440C

In my experience it does not lend itself to the qualities that make any of these items exceptional

I caution them because they are gluing scraps of things together and then sharpening them and cutting and hitting things with it and that can be dangerous

Good luck :)
 
TankEpidemic said:
We used the materials we had at hand to see if the concept was feasible. Also keep in mind that 440c was not used the first time around, it was some stainless steel we had laying around, we aren't even sure what type it is. We plan to use the 440c in a later attempt. We usually have the clamping down and stuff doesn't move like the previous two attempts, but it just didn't go right this time. 440c as much as we understand is the standard for a lot of commercial knife making (if i'm wrong, PLEASE correct me). What would you suggest be a better core? Also what do you mean by a carbon core? Did you mean the carbon we are using on either sides of the steel? Or did you mean steel with higher carbon content? Those carbon pieces are meant to take up some thickness of the blade to make the entirety of the blade lightweight, and to give the thin piece of steel in the middle strength at the same time. Also if were to make the entire blade of carbon fiber, my father and I would be in a bit over our heads, we don't know enough about carbon to make such an attempt.
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Some other folks have done laminated carbon fiber and steel core to some success at least in knives but most choose to use one of the carbon steels as a core .

As for a press think of a bowyers bow press

I have seen simple set-ups that use a form and clamps that are torqued down with a simple torque wrench

I have also seen some very ingenious presses that work by filling a section of fire hose with air.

Matt Diskin uses a vacuum press for his laminating things

Point is better results will be achieved with a more uniform process

Good luck :)
 
JParanee, I noticed you said that you own blades that have stainless on either side of the carbon steel that holds the edge. What this blade is, is a piece of carbon fiber sheet on either side of stainless steel that holds the edge. It is not two pieces of high carbon steel. It is not entirely made from metal. Also, thanks for the safety concern and heads up. I also think we should do more research into the type of metal we use to hold the edge in our blade. Thanks for all the insight you guys have given us, we really appreciate it.

EDIT: Didn't know you posted that before I posted my reply to your previous post. Wasn't sure if you understood the way the blade was comprised.
 
Tank respectfully I am not an idiot :) I know exactly what you are making, I sell carbon fiber for a large supplier at different knife shows like Blade etc.

What I am talking about is laminated blades that are constructed with a stainless outer core and a carbon inner core

Examples

B1204739-B014-4CC9-8928-2C49C05FC121-809-000000EDA61D7848.jpg


d8464086c6614c30afc2554336953a0f.jpg


c309b0ac.jpg


mirabile005.jpg


bowie026-small.jpg


Please do not think I'm being negative, I just want you to get the the best results you can with your time

Like I said Greg Lighfoot and Warren Thomas have had luck in doing Carbon Fiber outer skin and carbon steel core blades but these where knife sized articles that would not receive the stress of a sword

There has not been much luck or advantage to using carbon fiber outer skin and steel core swords so I wish you luck and like I said be careful swinging it into targets :)
 
fwiw, William Nease decided to go with all Ti, instead of a laminate blade for my Tikat, for the reason Joe mentioned.
As for a laminate sword holding up, time would tell. As I said before, they are cool though!

Rolf
 
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I was not putting you down in anyway, I may have entirely misread what you posted, my brain is a little weird today. Now I understand what you're saying. I may look into those knives that those two made, sounds very interesting. I also want you to know that I am VERY grateful for your input into this subject. It is invaluable to me and I feel very fortunate to have had it. Thanks.
 
TankEpidemic said:
I was not putting you down in anyway, I may have entirely misread what you posted, my brain is a little weird today. Now I understand what you're saying. I may look into those knives that those two made, sounds very interesting. I also want you to know that I am VERY grateful for your input into this subject. It is invaluable to me and I feel very fortunate to have had it. Thanks.
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Tank I know you where not and I did not take it that way hence the smiley face :)

There was a time that I did a lot of cutting and I've seen some scary things so that is why I caution you. You know the old saying its all fun & games till someone puts an eye out.:)

I only wish you success in your endeavors and even thou I personally don't see the merit in a Carbon Fiber /steel core sword over a good differentially heat treated carbon steel Sword I do see the neat factor and wish you success

IMHO weight is a factor in a good sword but.........balance, toughness, edge retention and wear resistance in taking blows and friction going thru targets will all play heavily in the construction & performance of a good sword

Like I said good luck and I anxiously await the outcome
 
JParanee said:
I don't know James, I have a lot of very good swords and none of them are made of 440 C.
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There's a good reason for that. I would not even consider making a sword entirely of mono 440C. That's completely irrelevant to this conversation.

This is about a laminated blade, and as you know, that opens up a lot of doors as to what materials are suitable for either the core or the outer layers. I have serious reservations about CF being strong enough to support a long blade that will be subjected to a great deal of stress. The core material is the least of my concerns.

Again, I do not know if Tank's idea will work. I would not go about it in the same way he is, nor would I choose the same steel for the core. Buy I do think it's worth exploring... especially since it's not my labor or money on the line :D
 
Very interesting work. Makes me wonder though what would happen doing the inverse. Sword with the spine milled out almost all the way down to the edge and with thin walls with a bar of carbon fiber inside it. Very little shearing force and a lot more abrasion resistance. Bet it wouldn't like flexing though.
 
Tank also all Carbon Fiber in not created equal and as you develop things reach out and I'll put you in touch with IMHO the best Carbon Fiber lay up guy out there. :)
 
james terrio said:
There's a good reason for that. I would not even consider making a sword entirely of mono 440C. That's completely irrelevant to this conversation.

This is about a laminated blade, and as you know, that opens up a lot of doors as to what materials are suitable for either the core or the outer layers. I have serious reservations about CF being strong enough to support a long blade that will be subjected to a great deal of stress. The core material is the least of my concerns.

Again, I do not know if Tank's idea will work. I would not go about it in the same way he is, nor would I choose the same steel for the core. Buy I do think it's worth exploring... especially since it's not my labor or money on the line :D
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James you yourself just said 440 C would not be your first choice :) so ........... Why should it be his ?

I believe that a carbon steel like 1095 or 1050 would be a better choice

I have been using a blade made out of Elmax for the last 2 years and I really like that steel but it is in a folder not a sword like object so I really don't know how it would hold up in that application

But for a sword to perform well it must be able to flex to a certain degree and return to center. I believe a sword that has a straight tempered piece of stainless with a carbon fiber outer layer would not stand up to this kind of stress well

This differentially heat treated blade returned to center

It is a 10 inch Bowie that was probable .33 at the spine at its thickest tapering down rapidly point is a good sword will do the same

L1000469-1.jpg
 
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JParanee, I very much appreciate the connection offer, but we have a carbon guy who has been doing this kind of stuff for over 35 years who is local and we met with very recently. Recently as in today and my father had a discussion about it with him, so I think we are good there, but thanks for the offer. :] Also thanks for mentioning different types of CF, we will definitely look into it... We did this with the knife and it does NOT flex very far, since it was so strong and so light, we decided to try out something longer, something that undergoes much more stress than this knife.
 
Glad you have someone local

When I say not all carbon fiber is created equal that means there are different ways to lay it up patterns, resins etc. and some might be more conducive to your purpose

Also under what pressure it was layed up with makes a difference in voids etc.
 
Also, for a number of years corvettes used composite springs made out of fiberglass, and they aren't very thick either. The were about 1/2" in the middle and tapered out to 1/4" at the ends. I assume if we find the right carbon fiber to use on this sword, it might be able to handle the stresses that swords undergo very well. Another thing I failed to mention is we don't even really know what type of CF we have, just some stuff we picked up at a surplus store, thought it was cool.
 
Tank

I'm sure your using a respirator while grinding, sanding Carbon Fiber.

If not please do so it can be very dangerous to breath Carbon Dust
 
Also before I screw up saying anything, I think some background is in order here. I am just a kid, and my father is the one doing a lot of the physical work on the sword and knives. He is a metal fabricator and does a lot of work on car bodies and other jobs that require his expertise. He is an excellent welder as well. His latest work are stainless steel guitars, if you would like to know more about those you can shoot me a message and I will be more than happy to give you info on those. Most of his work lately has been restoring vintage racecars. He has over 40 years of metal fabrication experience. I don't have nearly half the knowledge my father does when it comes to working with metal and most of the day hes off working and I'm here operating the account on this forum, uploading and posting picture, typing responses, etc. I'm an amateur blacksmith but my knowledge working with metal is limited. I got into smithing a year or two back (can't really remember when) and my dad borrowed a century old forge from a friend (which we later found in a sears catalog from the fall of 1900) and a century old anvil from a homestead property from another friend. He set me up with a stand and fixed up the forge, bought me a bag of coal and gave me a hammer to start off with. I absorbed all the knowledge I could from books and the internet, from people who know smiths and I went at it. I have so far made two knives and have since run out of coal. If I don't know what you are talking about, or respond weirdly, I either don't have the knowledge of metal to understand or my brain is acting a little weird. However I do know quite a bit from helping my father out in the shop with numerous projects, so it is not a significant handicap. :) I'm learning more everyday about metal and how to work with it, but again, I'm mostly here for the tech side of this such as posting here on the forums and posting pictures. :)
 
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Yes JParanee, my father is using a mask. The slivers are a nice surprise, he's gotten plenty of those in his skin, as have I. The smell of sanding on that stuff is pretty gnarly. XD
 
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