Polishing rough-finished steel

As noted in my previous post, many spearheads come from the factor with a coarsely ground and blackened finish.  This may be a cost-saving measure, but it's rather unappealing, especially if other your other steel items are already polished.  Here I'm going to try to give a better finish to the AntiqueCraftsShop javelin heads.

I'm starting it on a mini belt sander I recently got on eBay.  Sanding belts used for metal quickly acquire a smooth feel that belies the actual grit (size gradient of the sand) and are permeated with fine metal dust, so they should be kept separate from those used for wood and other materials.

The slightly hollow-ground faces can be sanded with a slow back-and-forth movement over an axle.  If they were a flat diamond grind, I would press the faces against the belt where it runs over the supporting metal shelf.  (This can be done to thin down the secondary bevels, though, since the angle needed to do so means the medial ridge is well clear of the belt.)  Care is needed at this stage not to mess up the medial ridge.  Once it's done, I turn the edges parallel to the belt sander to clean up any hints of unevenness created during this step.

Safety notes:  For some reason this sander's belt is set up to move toward the motor and up from the sanding ledge.  Also, of course, I am only holding the spearhead in one hand to snap the photo; you should always hold anything you are sanding in two hands whenever it's in contact with the belt, not only for safety but also because holding it in one hand often just doesn't work.  And, of course, wear safety goggles whenever using any power tools that grind, cut or drill.  I like chemical splash goggles that wrap against the face, making sure no metal fragments can get in my eyes again.

Sanding on top of the shelf allows you to press down hard on flat or convex surfaces, useful when trying to get rid of deep pits and grind marks.  Moving convex surfaces to the gap between the axle and shelf allows the belt to wrap slightly around the surface, giving a more even finish.

After polishing to 60 (top), 150 (middle) and 600 grit.

Some of the sandpapers used to give the final hand polish.  For this step I am tending to wrap the sandpaper around the back of one finger and use the other hand to rub the spear across it, following the alignment of the the scratches created by the belt sander.  With the blade faces, it's very difficult to follow the sander's marks.  I tend to instead just pinch the paper around the faces with my fingertips and rub the paper parallel to the blade; much easier, though not as effective.

The finished spearheads both illustrate the importance of using as many grades of grit as possible.  Each grade is able to remove grind marks from a slightly coarser grit, while creating new marks of its own, until you're using a grit so fine that its marks are undetectable to the eye (achieving the so-called mirror polish).  The spearhead on the left was initially polished with the 600-grit belt before moving on to finer grades of paper for hand-polishing.  As a result, it still has lots of grind marks and pits with black scale that the belt was unable to reach or remove.  The one on the right, which started on a 60-grit belt, has almost none of the factory marks left, but the jump from 150 to 600-grit left lots of marks from the 150-grit that the 600-grit belt didn't deal with.  These are visible not as black scratches but as bright, sparkly ones.  I'm not sure which one I dislike more.  Either way, the conclusion is clear:  I need to buy more stuff.

Cast arm fibula

Three years ago, I fabricated an arm fibula out of brass rod.  I was never satisfied with the lack of depth afforded by filing the details into stock that was narrow to begin with, so I've always wanted to replace it with one that was properly cast.

Last semester I took foundry at BCCC again and took the opportunity to make a few more reenactment items.  This one, which I finished up just last week, is wax-cast (as the originals probably were) and based on an example found at the Harvard Art Museum.

Although this is a huge step up from the brass one, I still made a couple of mistakes and compromises.   First, I had been meaning to replicate one from Deve Hüyük, and ran a simple Google search for this purpose, but didn't read the article carefully enough.  This example is of unknown provenance, although the article does point out that it's similar to two Deve Hüyük examples.   All three are of unusually large size, each around 4 inches/10cm long, with "bead and reel" decoration, flared at the base, and having fingers filed in after forging.

I cast it as a blind vent on a larger assembly.  The hand was cast as a bulb.  Unfortunately, I didn't account for shrinkage, resulting in a mushy hole where the wrist should've been, and the bulb fell off during de-gating.  I forged the bulb out into a flared catchplate roughly 1mm thick (finding out, along the way, that the Everdur silicon bronze Bucks uses actually hot-forges nicely).  Luckily, crack lab technician Ray was able to weld the catchplate back on, but the result is a much thinner "wrist" than the original has (it's still thick enough, though).

You'll also note that the proportions are slightly off.  This probably had to do with my inability to sculpt the wax for the beads and reels thin enough, and of course I bent the elbow a little too sharply.  The rough patch on the elbow is a remnant of the chill ball, and I may grind it smoother later on.  The original might have been cast straight and then bent, but I don't think this is the case, since it's slightly thicker where it's bent than immediately above or below.

The other problem that occurred with casting was that the slurry, which is quite thick, apparently failed to flow between most of the very thin wax noodles which formed the reels on my wax positive.  The first pair of reels just below the elbow cast fine. The second cast part of the way.  The rest cast as single thick reels with only a short groove in one or two places around.  This was sufficient as a starting place for me to file the grooves in, but it means that the grooves are sharp and the sides a bit square, unlike the nicely rounded cross section on the original.

The fingers were filed before bending the catchplate over.  It proved too difficult to get the bend in the catchplate to align with the pin, but as you can see, this was a problem with the original as well, so it's perfectly accurate.

I made the hole for the pin with a drill press, unfortunately a bit off-center.  The pin itself is simply a piece of springy 3/32-inch steel welding rod hard-soldered into place.  The original used bronze, but the bronze welding rod at Bucks was too thin and I imagined that brass would contrast unpleasantly with the orangeish Everdur.  In any case iron was also commonly used for arm fibula pins.

Conversion reversal

More than two years ago, I undertook a project of modifying half a dozen Native Way CH257 tanged triangular Chinese arrowheads into socketed Scythian-style trilobals.  The result was acceptable in weight though a bit crude in appearance.  However, when I shot them at Marathon 2015, the heads had a tendency to lodge in the wooden target while the rest of the arrow popped loose, as the arrow glue by which they were attached failed.  Arrowheads with the tangs left intact did not come loose.

I was left with two options:  order more arrowheads and convert them into trilobals without removing the tangs (arrowheads of this type are known from Achaemenid Persia, though rarer than the socketed types), or try to attach new inserts with a stronger bonding material.  In this case I chose to create new tangs by soldering the socketed heads to metal inserts.

Since the sockets were created with a 1/8-inch drill bit, it was easy to create the tangs from 1/8-inch brass rod.  I sanded the ends of the rod segments up to past where they would enter the sockets to make sure they were clean and free of oxidation, smeared a little solder paste (top) onto the tangs and placed the arrowhead onto the tang.

I worried that the tangs would anneal and wind up bending if they struck a hard target.  To try and prevent this, I clamped each tang up to 1/4-inch from the point in a heavy vise before hitting it with the gas torch, and applied heat only just until the solder melted and flowed around the junction.

The soldering seems to have been successful, but whether it will be strong enough to withstand shooting into hard targets remains to be seen.  With a melting point of 430F, this is not a "hard" solder, and the contact area can't be very large.

I also took the opportunity to anneal and straighten the tang of a Native Way G202.  While I have not yet tested it, I think that crooked tangs may run the risk of bending further when striking a hard target.  On the other hand, tangs that have been softened too much through annealing may also wind up bending.  These questions will have to wait until spring for answers.

Making an all-metal akinakes, part I

One thing I've long been unsatisfied with is the fact that all my attempts at making akinakai have had to have wood hilts.  Archaeologists have found a few blades with hidden-type tangs that might have comprised organic-hilted akinakai, but most of the finds I've read about from confirmed Achaemenid sites (Persepolis and Deve Hüyük, mostly) have solid iron hilts.  This is in keeping with the fact that the akinakes seems to have developed since the late Bronze Age as a one-piece casting with perhaps only a cord or leather thong wound about the grip. In the Iron Age, akinakes hilts would have most probably have been likewise forged in one piece.  One or two finds from Persepolis are grooved in such a way as to suggest that the hilts were folded around the tangs from a thin bar, while another is an iron knife with what appears to be the bottom half of an akinakes hilt made of bronze, with a groove completely bisecting the guard.  Metal has the advantage of being less delicate than wood and so the hilt can be less bulky.

Now, hot-forging anything more complex than a tanged leaf arrowhead is well beyond my skill.  However, as last year's Elamite dagger project shows, shaping with a cheap angle grinder requires very little skill, and I happen to have access to a drill press at the moment.  With care, it may be possible to fabricate a slab-tanged akinakes that looks passably like a proper one.  Since the grip will be wrapped with leather, the use of a slab tang should be less obvious.

Right.  As before, the blade and hilt are sketched onto normal paper, folded and cut, then glued onto cardstock and cut again.  I did these while still planning another wood hilt, so they are not quite as according to the current plan.  I cut off the pommel section of the hilt tracing, then traced the rest onto a scrap piece of 1/8-inch steel, and added a straight line so as to first bisect the piece so each scale can be cut out and shaped without damaging the other.  The pommel will be made from 1/2-inch bar stock.  The blade will be from the leftover 1/4x1-1/2-inch bar from last year's Elamite dagger.

Next I glued the hilt pattern to the blade, using the folding lines and the bar itself to ensure proper alignment (as you may have noticed, the hidden tang on the original blade pattern was crooked).

It would be ideal to use a large plate so that the guard can have a corresponding full profile on the blade, but this is what I have to work with, so the sides will have to be filled with extra steel bits traced from the severed wings.  A slight gap will probably remain since this bar stock thins down a bit toward the edges.  Perhaps adding lots of solder will help.

The tang will be much narrower where it passes through the pommel.  This same method was used on the Naue type II of LBA Southern Europe and while it's not accurate here, it should mean the pommel has to be filed out a lot less.

This next step ought to have been done earlier but it's not a loss yet.  I punched a couple holes in the pattern with a hobby awl to mark the rivet holes and widened them with a thin file.

That's all the work I'm doing for today.  The holes need not line up precisely, since they'll be filed wider to fit the pins - as long as a thin round file can pass through, that should be sufficient.

Making an Elamite dagger, part V

Since one grip scale bowed outward a little (probably due to unevenness of the tang rather than the scale itself) I pressed it into place with epoxy and weights, using one pin to ensure it was sitting in the correct position.

I cut up the pins with the angle grinder and gently rounded off the ends to prevent raggedness when peened.  They should protrude above the scales just a few millimeters on both ends.  If you cut them too long, you can grind them down a bit; obviously, if they're even a little too short, you have to start over.

Any old block of metal can serve as an anvil for setting the pins.  Hammer them down until they're flush with the scales.  The hammer does unfortunately leave discolored marks on the wood which need to be sanded off and a final coat of linseed oil applied.

Here you can see that the scales were a bit too short to cover the triangular ricasso.

With handling, the slick appearance and stickiness imparted by the linseed oil will dry up.  The dagger is far more comfortable to hold with the scales in place.  The leaf shape gives it plenty of blade presence; it feels like a chopping blade despite being little more than a foot overall.

Making an Elamite dagger, part IV

I rough-cut the grip scales on a band saw months ago out of a 1/4-inch maple plank from Lowe's.  A more historical material would probably be Eurasian walnut (Juglans regia, aka Persian, English, European, Circassian or common walnut).  Unfortunately the American black walnut planks I had on hand no more closely resemble Eurasian walnut than maple does.  The maple was the remnant from the same plank I cut the scales for my letter opener from back in 2015.  I sorted through the selection at Lowe's to get one with the most visible curl.

After much dawdling and working on other projects, today I finally sanded them down to the correct shape.  The most tedious part of the process is channeling out the undersides of the scales to fit into the flanges, and I failed to get a perfect fit.

To the right are some common nails annealed by gas torch, which, when cut up, will serve as substitutes for the iron pins on the original.  I think I'll be able to get two pins out of one nail, but we'll see.

While a light brown stain might have popped the grain more and given it a slightly closer resemblance to walnut, I am awfully fond of the look of pale wood on dark grey steel (similar to the bone scales that were prevalent on similar swords in the late Bronze and early Iron ages), so instead I'm going straight to the linseed oil finish.  Sufficient coats of linseed will turn pale wood golden yellow, a color similar to antique bone.

Making an Elamite dagger, part III

After multiple sessions of cold-forging and polishing, the blade is finished.  I tried to anneal the edges of the tang with a flame weeder, and I do think it helped.  As you can see, I didn't manage to polish out the last of the grind marks.

The flange is quite shallow, maybe a millimeter and a half at the most.  But I think even one this shallow will serve its purpose.  A higher, thinner flange could, as I understand it, be crimped a bit into the scales to provide much better hold on them.

Some of the equipment for raising a flange.  For me, both hammers proved necessary:  The cross-peen hammer's narrow face gets into concave curves that the claw hammer is useless against, but the cross-peen hammer's round face has nasty concentric circles that transfer onto the medium, so the claw hammer's smooth face is necessary for all straight and convex edges.  Another useful tool is a table clamp for holding the blade while hammering on the top of the pommel area, since bracing the blade's thin point against anything would risk damaging it.

I finished up with the usual combination of various grades of sandpaper ending with the Dremel's carbon steel brush.  The initial sanding also included a round file about 1/4 inch thick for roughing out the narrowest curves.

Making an Elamite dagger, part II

Couple of weeks ago, I went to town with the angle grinder's flap disk.  In about an hour and a half, I removed a third of the tang thickness and completed the primary bevels.

I also did a quick polish to round off the now-sharp edges and highlight remaining problem areas.

Getting the tang down to an even thickness is proving difficult.  A nice surprise was how easily the little chevron shape on the guard formed as a result of adding the bevels, but unfortunately, I don't think the scales I selected are long enough to cover it, so it might wind up as a very small ricasso.  Although it has practically no distal taper before the point, the blade now feels light and sword-like, balancing about an inch in front of the guard, which will likely move even farther back when the scales are added.

What didn't go so well?  The flap disk does the job fast, but it left behind many deep grind marks which will be difficult to polish out.  The flap disk also seemed to produce a slight hollow grind on one side of the centerline.  And keeping the centerline from wandering was pretty difficult...

...  which resulted in this, the blade becoming too thin below the shoulders, where I tried too many times to correct it.  A well-made sword blade should be at its very thickest at this point.  Hopefully, the original grinding wheel can get rid of the flap disk's grind marks and reduce some of the uneven thickness a little more slowly.

With the edges safely rounded, I could feel and sorta see that where the blade should be at its widest, the edges are faintly convex.  As well, I learned from my belt knife project that the flanges don't require that much extra material, so I should make the tang narrower by perhaps a sixteenth of an inch.

I've halted work for several weeks, because I have other things to do and the weather in Bucks County's been cold and rainy (grinding is too noisy and produces too many steel filings to work indoors).  I intend to pick up again a week from Sunday, after my woodworking class ends, hopefully correcting all the above issues.

Making a belt knife

As I observed at the time, one takeaway from Marathon 2015 is that we still sometimes need a small but sharp knife around camp for mundane jobs.  Since my flanged dagger project will require grinding primary bevels and cold-forging flanges anyway, I decided to practice these skills and acquire a needed accessory in the process.

The knife is inspired loosely by one seen in Oriental Institute Publications 69 (pg. 311 of the PDF) and, to a lesser extent, one with a more extreme recurve found at Deve Hüyük.  Mine doesn't exactly resemble either of them, and is sized to be useful for tasks like cutting rope and opening boxes.  I don't know what the purpose of the recurved shape is, but it's pretty common, used by the Romans, Thracians, and in South Asia, so there must be something to it.

The lack of any blade shoulder gives it away as a utility knife with little use as a weapon, as there's nothing to keep the fingers from slipping onto the blade if used for stabbing and it's too small to put any power behind a slashing attack.  Of course, that does make it a bit less safe as a tool as well; even most utility knives have a bit of a shoulder, but not all, so if you're not reckless, it's fine.

I markered the outline freehand on 1x1/8-inch mild steel bar stock, added the rivet holes with a drill press and cleaned them up with my Dremel's cone cutter.  I cut the outline with my angle grinder and did the primary bevels with the standard stone grinding wheel.  I intended for it to have a flat grind from the spine, but when the edge started to get too thin, it wore away and deformed.  Perhaps being overly cautious, I wound up giving it a convex bevel that only extends about half its width.  As a result, the blade is very sturdy but probably won't get too sharp.

Forging the flanges was easy enough (took a lot of effort, but that's just my lack of stamina talking), but there was still quite a bit of extra material, which suggests that I might want to go back and reduce the extra width I added to the flanged dagger tang for that purpose

The grip is black walnut, cut and drilled at Bucks, with a simple linseed oil finish.  The trick in drilling rivet holes in a grip of this type is to chuck up a bit on the drill press, hold the blade either over the edge of a block or preferably in a vise so that the tang sticks out, and position it so the drill bit is sticking straight down through the rivet holes.  Then slip the grip onto the tang, making absolutely sure not to move the tang at all, start the drill press and lower it until it drills through the grip, passing through the tang holes in the process.  It's a delicate job even with modern equipment and a humbling reminder of what clever bastards ancient people were.  I understand that a clamp is preferable for holding the blade but there weren't any in the shop that would actually work for the purpose.

I made the slot a bit too wide, requiring a shim (that little pale edge peeking out between the blade and grip), and the grip is a bit too narrow between the flanges, which I didn't notice until after drilling.  So I rounded off the ends of the flanges so they wouldn't bite into my hand.  Rivets are simply an annealed common nail cut up with the angle grinder's cutting wheel.  The sheath is heavy molded rawhide with a welt and glove suede facing, painted with the Iranian rosette and just tied to the belt with a suede band.

My camera didn't want to focus on it, but I found the rope-like seam produced by single whipstitching very interesting.  When the needle initially entered the leather from the front, whipped around and passed through the front again, the seam on the back was curled forward into a shape I found oddly reminiscent of the edging seen on ornate akinakes scabbards (see here, third photo from the top on the left).  Obviously the resemblance is not that great, but I could imagine this kind of leather seam edging, whose decorative quality is purely incidental, as being distantly ancestral to that used on what are presumably metal facings.