Question On Bar Twisting

[DiamondG Knives]

Hi Guys
Im wanting to make a composite core billet with two oppositly twisted bars, Im thinking this will give a chevron effect?

My question is this: I understand that I need to round my bars somewhat before I twist them. Im wondering what the diffrences would be between forging the bar round, and grinding the corners off?

Iam I correct that the lower layer count will give stronger lines? What is consider low layer count?? Im at 24 right now, and thinking Ill go with that number to ensure a bold pattern.

Also, on a 1' square bar, 12" long, what is the reccomended number of twists? Ive heard 2-3 per inch, is this adequate? As I said, Id like a chevron look down the middle once the two bars are joined togather. I plan on doing this by using 2 bars same length, twisted in opposite directions the same number of times. I know it sounds much easier than it is, just somthing Ive wanted to try.

Thanks and God Bless
Mike

[Jeff Pringle]

Im wanting to make a composite core billet with two oppositly twisted bars, Im thinking this will give a chevron effect?

You are thinking right.

My question is this: I understand that I need to round my bars somewhat before I twist them.

This is to reduce stress, and make delaminations less likely, from what I have read. Seems to work, too.

Im wondering what the diffrences would be between forging the bar round, and grinding the corners off?

Don't know, I only done the forging of the corners.

Iam I correct that the lower layer count will give stronger lines?

You are correct, a more graphic pattern, visible across the room or battlefield!

What is consider low layer count??

For the early medeival, 5-12 is low. For modern knifemaking, anything under 50 seems considered low. For reference, check the migration era post by J. Loose in the display case - that looks like ~9 layers; the viking sword I have in the historical insp. forum was eleven.

Also, on a 1' square bar, 12" long, what is the reccomended number of twists?

Sorry, I know it's a typo - 1' X12" is a cube, very hard to twist!;-P... For my blades I work with roughly half-inch bars at the twisting stage.

Ive heard 2-3 per inch, is this adequate?

Just remember there will be stretching of the pattern, so make it about as tight as you think it needs to be, then twist it some more. I'd recommend making it as tight as possible.
I look forward to seeing what you come up with, keep us posted!
Jeff

[fischerknives]

Diamond G,
You're partially correct in saying you need to round your bar somewhat. In my experience, for best results, you really need to hammer that bar as round as you possibly can. It's not hard to do, basic smithing really. Hammer it into an octagon first then round it from end to end. I like to finish the billet in the power hammer by holding it lengthwise in the dies for a very uniform finish. If you don't round it first, you can get shears and a lot of wasted steel. When you flatten out the twisted billet, what you'll see is a v-shaped gap on each side of the billet at every twist and quite possibly a crack that runs from side to side at each v. Be aware that hammering your billet into a round bar will definitely test the quality of your welds - I believe that hammering it on it's corners really puts a lot of stress on it. Start off hammering gently on the corners, working your way from end to end, working each corner uniformly and you'll minimize the chance of shearing your welds. You'll also want to flux it before you twist.

Grinding off the corners might be easier than hammering round but consider that hammering the corners round will give additional movement and character to the billet - this is always a good thing. You'll also waste a lot of steel grinding it round. Besides, isn't hammering more fun than grinding???

The number of layers and twists is entirely a personal choice but oddly enough, more people ooh and ahh over the low count stuff (like 30) than the high count that you slaved over for an extra hour. Go figure. I guess it has more visual impact, initially. Of course the longer you study it the more interesting the higher count stuff becomes.
If you'll put a little extra effort into getting the billet ready to be twisted, I think you'll be much happier with the results.
Good luck!

[J.Arthur Loose]

Mike,

The way to get a really nice bookmatch is to split & open up a twisted piece lengthwise. Not quite a chevron, but very pretty. I keep meaning to try an interrupt this way.

I always forge round rather than grind, though there should be a difference in the resultant pattern. Hafta try it some day.

Traditional layer counts in Migration Era pattern welding are 7-9. 12 would be high.

That's pretty much how I did the pieces I just posted. about 3/4' diameter 12" long. 3 full twists per inch. This will result in 6 stars, as you can see. Secret to lining up: you can adjust lengths to match when forging square again.

[tonn]

I like to twist with sharp corners and then welding bars together without flattening. It gives a wawi line between bars.

Not recommended with more than 5 bars!

About twisting & splitting
It's important not to do it in the "right way" as blacksmiths do. Just split from one side down!!
And use a thin chisel.

[J.Arthur Loose]

When twist & splitting I first twist, then forge square again, then grind relatively clean on all four sides. For the actual split I have very good luck using the bandsaw, since splitting with a chisel is messy & the further you get away from the core the more un-bookmatched things get.

[paul harm]

i twist with it square , then grind the sharp edges before i flatten it. paul

[DiamondG Knives]

Thanks for all the input and ideas guys! This has been on my "want to try" list
for some time, just trying to get it in my head how I want to do things before I start.

So once I twist, Im assuming I will gain some mass, as it will pull itself inward while twisting, just curious if the is anything to be careful of while Im stretching it back out, I plan on using my flat dies in the press, and just keeping things square.

Thanks Again!

God Bless
Mike

[tonn]

Originally Posted by J.Loose

When twist & splitting I first twist, then forge square again, then grind relatively clean on all four sides. For the actual split I have very good luck using the bandsaw, since splitting with a chisel is messy & the further you get away from the core the more un-bookmatched things get.

Yes! Splitting with chisel is messy. Bandsaw must do much better. Unfortunately I don't have one.

[DiamondG Knives]

Well guys, I did my first twist las night. was happy with the results, started with a 10" long x 1" square bar, forged round, then twisted a total of 36 twists (I think )
Then flattend the bar and edges to true things up. Came up with a zebra stripe look, wich is very attractive, but Im thinking that if I were to grind the corners off, I would get more even lines. Anyone have any opinion on this??

http://knifenetwork.com/ppost/showphoto.php?photo=474

Thanks and God Bless
Mike

[rhrocker]

That looks great Mike! I tired one recently, same measurments as yours, but probably twisted 50+ times. The lines got lost in the twist, they're way to fine. Yous are just the right size, and to me, spaced nicely.

[fischerknives]

Mike,
That looks great to me. You sure this was your first time??? Looks like your welds held up fine too. Play around with layer counts and number of twists for unlimited variations. It will make a great looking knife. It would be fun to see a pic of the finished knife. How many layers was this?
Fischer

[DiamondG Knives]

Fischer:
Thanks for the kind words. Im guessing here, but Im thinking it was fairly low count, under 25 layers or under. And it was my first twist, there are so many patterns and ideas I want to try, I forget about half of them before I ever make them!

God Bless
Mike

[fischerknives]

Mike,
I'm with you on all the patterns I want to try - I'd guess that everybody in these forums would say the same. There just isn't time. But that's what's great about bladesmithing/knifemaking - the endless challenges. I'll never master them all, but I'll sure keep trying. I just don't understand people who are bored; I have never been bored! Can't wait for retirement so I can spend more time in my shop.
Take care!
Fischer