Greave Front Production
There are many ways to achieve a desired result when working with steel. I think that most modern people are used to thinking
of the material as a sheet and the ways we think about wood or cloth get stuck in our minds. The original shape or thickness
governs the result. This is most obvious when people start and they curl metal into forms that (very roughly) fit around a body part, add some straps and call it armour. Maybe they flair an edge, or roll an edge. Maybe they add some shaped pieces from
Rough from the Hammer, but the metal movement is pretty simple. Even when people move to more advanced metal work, many elements still seem to based on the same idea. Cut out a piece, dish or raise it some and you get armour. That can work, and it can work perfectly reasonably, but metal can also be thought of more like clay than cloth. You don't just bend and seam it, you really push it around to make it go where you want.
It can also help to "think outside the box" - twist your mind sideways when thinking about things. Just because a part of the piece of armour sticks out from the rest doesn't mean that you should flair it out. That might be the easiest and best thing to do, or it might be better to take the metal from another part of the piece to minimize thinning.
A greave is a nice illustration of the concept. The simple form is a curled piece of metal with edges that allow it to fit onto the shin. Then people flair the bottom a little and dish the sides some and it gets a little better. After that people start trying to copy real pieces, or the shape of the lower leg and things get interesting. The desired shape is, in no way, a flat piece of metal that is curled up. The shape you really want is a lot more complicated, and a lot more interesting. It flows with the body.
It follows the form of the leg, but often attempting to improve on the basic shape - to idealize the form while still allowing
the wearer to move comfortably while being protected.
I expect that there are a lot of ways that you could achieve the desired shape. I don't think any of them are inherently better or worse than the other, as long as the result is correct. All of these are really describing how to get the overall flowing shape. Each will involve a certain amount of dishing/sinking/squashing at strategic spots to get the rounded shapes at the calf and ankle bones. I omit that part of the process for convenience. A quick listing of possible ways you could attack the main problem of getting something that tapers in the top half and flairs in the bottom half include:
- Make a pattern that (roughly) allows you to have the material mimic the top two thirds of the result and flair out the bottom until it works. The result is a very, very thin lower edge, or a very thick upper part.
- Cut the pattern in two halves, allowing you to get a flair when you weld the parts together down the middle. This works, but it is annoying and you have to clean up the weld down the center.`
- Piece the parts from even more parts, I have seen and can see up to about 4 (top, bottom and left, right) working. Much more than that and you are just adding more welds without much gain. If you like welding and don't like moving metal, this can work. I don't. When Aaron and I made a greave form from 3/8" plate, we definitely did it this way.
- Raise the middle in to bring it into the proper place. This allows the ends to maintain their original thickness. This appears to be the most common way these days. It can work very well, esp. when done hot. Small heats help move metal where you want it to move and have the cold parts keep their shape.
- Curl the piece to match the desired profile then raise the sides down to fit to the leg. This can be very fast, if done hot. Small heats help move metal where you want it to move and have the cold parts keep their shape.
- And then there is the way described below......
This shows a little experiment I did to see how I might use drawing instead of raising to make a greave.
This was done cold from mild steel as an experiment. From my experience, annealed 1050 works similarly at this stage of processing. I am pretty sure I started with a piece of nominal 16g. This is thicker than people use for greaves, but the whole process is based on thinning, so I wanted to be sure to have enough material. Hammering and grinding and it will get thinner.
I used a power hammer to start the process, but that is just because I had one. I have done the same process by hand. It took longer and I didn't lay out the pattern for intentional thinning of the top and bottom because that would just have added work. With a power hammer, this doesn't add much time and it was fun.
Click an image to see a larger view of it.
Pattern
This is approximately what the pattern should have looked like. I started with the same shape,
but the sides were straight instead of curved, it had an extra inch on the bottom, and the foot
was not cut out. I would likely add a little to the outside bottom corners or trim every where else
down the side. This will help with a shortage of material at the bottom back corners after the piece was shaped. The foot hole is also very generic - you could make a 16th c. or 15th c. greave by trimming differently. Normally most people will cut this out very early in the process. When working this way the material in the cut-out isn't really in the way, so it can be left for later. This allows you to see where the material is going and adjust a little to match your preferred final form very easily.
I was aiming for a 15th c. greave. I have relatively little rise on the outside because I planned to draw the metal out vertially there
to achieve the proper shape. One of the goals was to play with a pretty generic shape that would have been "material efficient" and easy
to cut with straight shears. That, and the fact that I hadn't actually used this exact method before is why I started without cutting out the foot.
If I were actually carefully building a greave for myself, I would probably start with a slightly narrower pattern since the result wraps a little
far around. But I am pretty skinny (6 feet tall, 175 pounds). Starting with the right shape eliminates all of the hammering on material that just gets trimmed. One nice thing about using this method and a power hammer is that the initial shaping time is just a few minutes. So having some extra material isn't really a problem. When you are raising a large form an extra inch or two around the edge really adds to the work.
If I actually did this very often, I think that it would be pretty easy to know how much to flair in the various places to get a pretty even
thickness end result and minimize the hand forming necessary to get a "pretty" shape. You could also have a process where the apprentice
moves most of the metal and the skilled craftsman finishes it off getting the final shape pretty quickly.
Tools
The intial shaping was done with a cross pien on a flat anvil face. In my case, I used a power hammer to do this, but I was careful not to
hit very hard. The force required is well within the bounds of hand hammer work. I have done it on a pair of greaves in the past. When you are whacking a piece of 16g mild steel sheet with a 50 pound power hammer, you really do want to have a pretty light touch.
Almost all of the hand shaping was done with the flatter faces of the left 3 hammers.
They provide different shapes of "almost flat" faces that allow me to hammer over the outside curve and into the inside curves.
The "raising hammer" was used a little bit from the inside to push some narrow areas out over a flat faced anvil. I expect that I could have done all of the work with a version of the second hammer face with slightly rounder corners, but I like to move back and forth between hammers that approximate the desired final shape. I expect that they didn't do that - to time consuming.
Much of the rough shaping was formed on a pipe stake.
Most of the rest of the shaping was done on the front half of the rounded horn of my bick horn. This allows me to get the right curve inside
the piece to allow for shaping.
I did also use a flat anvil face and hammered from the inside and a hatchet stake for forming the crease. I also used a couple of slightly
domed stakes for the rounded areas of the calf, but not a lot. I had achieved a lot of the real volume necessary using the power hammer and "squashing" the areas to shape.
Stages of hammering
Initial cross pien work - from the flat
This is what the piece looked like after the initial hammer work using the power hammer.
It really looks like a mess, doesn't it?
The goal of this stage is not to make a nice shape, it is to get material where you need it to achieve the desired final shape.
I drew out the top section to provide some of the shape
and to intentionally thin the area that would otherwise have remained thicker. I hammered the areas of the calf muscle bulges to get the rounded shape I will want by the time I am done.
The center is flaired vertically on each side and the bottom is flaired the normal way.
This allows me to move the metal around and thin the metal relatively evenly while getting the sweep in the center line that makes a nice greave.
When I did this by hand, I did the central sideways flairs when the piece was flat, and then worked the rest as necessary. I did not hammer nearly as much of the surface with a cross pien.
Viewed from the side after the rough flairing. It looks pretty stupid at this stage, but when you curl a piece up it flattens out a lot,
so having a lot of flair is a good thing. I really had no idea how much flair I needed, but I thought this might be close to the right amount.
In hind sight a little more of the vertical flairing a little lower down would be a good thing. It would help get the "kick" out at the
ankle. It would also mean that you need even more material in those corners because the piece will bend forward more.
Viewed from the inside after the rough flairing. This helps to see how the hammer was placed to thin in the desired directions.
Curled up to approximate shape
The rough shaped curled up. No real additional shaping has been done, but the piece comes closer to fitting the leg.
The same curled up shape from the side.
And now hammered into a nicer shape
After some hammer work to move material around to make it look more like a greave.
Assuming the time stamps on the pictures are right, including taking pictures, this is about an hour into the process.
The same stage shown from the side. If I had dished the center of the top differently, and moved the side flairing down a little bit I am well on my way to the back of a near-floor length 16th c. greave. And it wouldn't require either lots of raising or huge amounts of flairing at the bottom.
And after a reasonable amount of work turning it from "greave like" to more "greave shaped"
From the front
The same stage, from the side. This shows the general sweep in the front center line. Most of the initial flairing was done in order to get
the material in the right place to have this sweep without having to flair the bottom excessively. The top is flaired at the center to
allow for the muscle at the base of the knee cap.
Since this was just for fun, this is where this greave part ended. It lies in the shop rusting away. But it shows what can be done.
Conclusion
This is really just an illustration of a concept.
We think of a piece of armour as "flaired" at the bottom. Often this could also be described as "longer at the sides" - when you think about it that way, a whole new way of working opens up. I recently made a cheek plate for a burgonet. The cheekplate is dished over the ear so that it will fit the bowl and then "flaired" at the bottom to mimic the tail. I did the work by dishing the top, flairing along the front and back sides and then along the bottom a little bit. Since I hit the entire surface, the result was relatively even in thickness. This put the material in the right place to get a nice "flair" without thinning the metal along the bottom.
It is just another application of the same idea. You can see the result here:
Burgonet with new cheek plate.
The other example I have used to illustrate "sideways" thinking is making a gusset. Specifically one of the ones with a nice big roll at the center. Like these:
When I work on these the pattern is approximately a long, thin rectangle.