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Forging the Plunge


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Hey folks, I was hoping some of you might have some tips on forging the plunges. I've been struggling with the transition between the ricasso and the blade. I believe it is generally preferred to have the plunge line inline with the heel of the blade. Note the picture below. I'm want to get the plunge to be where the green line is. The problem is that when pulling down the blade edge there are hammer marks in the circled red area that need to be ground away, which means I have to push the plunge back deeper into the ricasso. Basically the problem is that I can't get a sharp angle between the ricasso and the blade. When I forge it, the transition slopes from the ricasso to the blade, and I can't see any way to avoid that.

IMG_2207.jpg

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A square-faced hammer properly dressed and a matching edge on the anvil, combined with excellent hammer control are all three required to do this.  You could also make a guillotine fuller-type tool to do it, but it would only work well for one specific thickness

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I do it as Alan said but I do not have the expectation of it coming out perfectly sharp and crisp. It is a hammer and anvil thing not created with forging dies after all. I "mark" or start the plunge lines then keep the blade on the anvil with the ricasso and tang off anvil in the tongs and "pull" or draw the blade down .

I fully expect to have filing to do both squaring and evening up the plunge lines. You are right, there is no way to avoid it. I have tried to design a guillotine tool in my mind for it but I can't get over the hurdle that Alan mentioned. With sharp dies it might give the result you are expecting. Given vagaries in grips hammer and anvil angles, expansion and contraction of hot steel I settle for what I can get. I was just thrilled as heck when I figured out how to use the anvil to get that much.

Edited by Vern Wimmer
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I do exactly as you described, and it seems no matter how careful I am, the simple fact that I'm hammering steel against an anvil means that I can't get a transition that has to be ground back somewhat. I've been thinking about making a guillotine tool for this, maybe that's what I'll have to try. How sharp is the radius on you hammer and anvil where you do this?

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I have  sharp corners on my Harbor Fake ASO but you have to be realistic here. You are hitting one side to get a line on the other side then you are flipping it over and hitting the side you just made a line on to make a line on the other side. This is hot steel you're hitting and it moves, that's why we heat it and hit it in the first place. It is also why the gods made safe-sided files, for us poor mortals to straighten things up with.

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If I'm using my normal sized stock, I'll use the guillotine tool I made. If it's some other size, I'll do it by hand how the others described or on some drawing dies on the press.

These are the dies I made for the smithin magician I have. They work pretty well.

20180508_164511.jpg

Edited by Cody Killgore
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Im not sure if this is a good method or not, I need to try it more.

I have forged a chisel grind plunge, so its flat on one side with the plunge on the other, and then centered the plunge after it was forged.

Im not sure what the effects of pushing the edge back and forth are, it might leave too many dings and it would show up in patterned steel because of the uneven forging. I try to go at it from both sides but its not perfect in that way.

I might also do some careful forging with a ball/cross pien to draw out the heel towards the rear of the blade.

When I forge a blade I try to keep that area thick starting from the preform phase and I try to go for a convex distal taper so mistakes in front of the shoulders of the blade are easily ground out.

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The tool Cody pictured is the thing I was describing, cool!  The radius doesn't matter much as long as it's A: not a sharp corner and B: the same on both hammer and anvil.  The most important thing is to never hit the ricasso again after you do this.  Vern described it well. That's where hammer control (or the lack thereof) comes in.  When the late great Larry Harley taught this he'd stand across the anvil from the student with a long broomstraw just touching the plunge while the student hammered, repeating "Don't you touch my ricarso!" every second or third hit.  And yes, he pronounced it that way. :lol:

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Someone on here once posted that once they have the ricasso area forged to thickness, they hold the blade there with flat tongs to keep them from hitting it with the hammer.  It is more of a reminder to not hammer there anymore than true protection against errant hammer blows.

I'm still filing/grinding the plunges in, so I haven't evolved to the point of worrying about this yet, but thought is was a neat idea, and sometimes use it for other areas.

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I forgot to mention something important about doing the dropped edge at the plunge:  once you forge the plunge, which you do before forging the bevels, it really helps to use a corner of the pein to pull that little shoulder down below the ricasso.  This is where Brian's suggestion is not just a good idea, but almost a necessity to help shield from errant hammer blows.  You will be forging at an angle towards the ricasso, a very tricky thing to do without excellent hammer control.  Once you have a little blob of steel pulled down in that corner, start the bevels with the cross pein (or straight or angle pein, doesn't matter) aligned with the edge.  This will pull the whole edge down without causing the spine to curve the other way.  Don't go too thin or be too aggressive, those narrow divots can be a pain to clean up if they're too deep.  Work from the edge to the spine, then clean it up with the flat face.

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One could also make a hardy tool, like a fuller or pein, with a flat face. It could be used with the blade level and the hammer plumb to avoid having to dink with all the angles using the anvil corner and a miss hit bending things.

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