Ok, you've got the blade finished: forged or ground, final-ground, heat-treated, polished. Now you need to make a fit a guard. On this I'm starting off with flat brass stock.
And yes, this would be faster and simpler with a mill. I don't have one, so.
First, figure out how long and wide you want it to be. If in doubt, make it a little oversize, you can always cut it down. Mark the width and length and draw the lines, using either a fine-line marker or a scribe. Then mark the centerline of the guard-to-be. Lay the blade on it so you can mark the width of the tang;
here I'll usually mark it so the slot will be a touch less wide than where I want the guard to sit; you can use files to widen the slot, but it's a problem if you've made it too long. If I use a marker for these, I'll go back and use a scribe to cut the centerline from side-to-side of the tang, reason to be shown later.
Now to the vise and hacksaw. Cut the guard from the flat stock, I'd suggest cutting just outside the lines.
With the guard cut,
you need to mark it for drilling. Here I use a prick punch. Same as a centerpunch, except a much longer taper to the very sharp point.
Use a prick punch when you want to lightly mark a spot, centerpunch for a deeper mark. Here's where the reason comes in for scribing the centerline: the fine point of the prick punch fits into the line the scribe cuts, making it easier to keep the marks all in line. With brass, you can use a pretty good whack if need be; for steel or other harder metals, only a light tap or you'll smash up that nice, sharp point. Make a series of marks, spaced as you see fit.
Now to the drill press. You can do it by hand, but use the press if you have one/can get the use of one. Measure the thickness of the blade where tang meets ricasso, and choose a bit just a touch thinner. On each hole, just ease the bit down to the punch mark and it'll help center itself, keeping everything nicely in line.
There's a piece of fine wet/dry sandpaper handy on the table; no matter how sharp the bit it'll leave a bit of metal sticking up around the hole when it goes through, so after drilling lay the piece flat on the paper and give it a few strokes so I'll lay flat. Then on to the next hole, repeat however many times.
Now you have to join the holes into a slot. Out with a jeweler's saw. Clamp the blade on one end, slide it through the end hole, then clamp the other end. Clamp the stock in a vise and start cutting*.
Take it slow and very light pressure, as these blades will break easily(there's a reason they come in bundles of ten or twelve). Takes a bit of practice, but you can hold the blade right on one side of the hole and take it down to the edge of the next hole, giving a nice straight cut. You can use just two holes, one on each end, and on short slots I do, but if it's very long the holes give you places to stop and lay the saw down and rest your hand. When you reach the end you can either work the saw back up to the top, or flip the stock over and cut the other side.
The slot
should now be a little more narrow than the tang/ricasso where it should sit, and a touch shorter than needed, so out come the files.
Cutting out a slot this thin means thin files, sometimes hard to find. If you plan on making guards this way, plan on getting a handful of files and modifying them. Remember that belt sander I've mentioned as being so useful? You can use it to make 'safe' sides on a file(smooth sides that won't cut)**, to narrow or to thin it. I use needle files about 6" long for opening the slot up, then a couple of fine-cut regular files 6" or 8" long that've been ground to different widths and thicknesses to I can fit them in where needed. Take your time here. A sharp file will cut a lot faster than you might think, especially on a soft metal like brass, so it's easy to cut too much. Also, keep a wire brush handy to brush the filings out of the file surface, you'll get smoother and faster cutting.
Slide the tang into the slot and get an idea of how much stock you need to remove, mark with a pencil or something if need, then clamp the piece in a vise and start filing. Cut a few strokes and try the fit, cut a bit and try. There's no way to rush this that won't wind up with a slot either too wide, too long or uneven. Ideally, you want a fit that gets to just a tiny bit short of where you want the guard to sit, so you have to give it a tap or two to seat.
It may well be that you wind up with the width of the slot just right, but the slot is a bit short.
That's fine, use the files to widen it. Here's another reason to make the slot a little shorter: you use the files at an angle here, so you widen the slot on the blade side, keeping it shorter on the tang side.
On tapping it into place, two ways. One is to narrow the jaws of the vise to just a touch wider than the tang, hold the blade***, slide the guard onto the tank and the tang into the jaws and tap. The other is to get a piece of hardwood longer than the tang and either drill a hole into it from one end(narrow tang) or cut a slot from one end back long enough to fit over the tang. Clamp the blade in the vise at the ricasso(padded or some non-marking jaws, please), put the guard on, slide the wood punch in place and tap on it.
You've now got a guard tightly fitted to the blade. Now's the time to finish the guard(shape, polish, etc.). Here I want it bent forward on both sides so I use a spacer to keep the slot from being bent and clamp it in the vise and use a hammer to tap each side forward.
Then I'll grind the thing to final size & shape, then polish. In this case I used first 100 grit wet/dry paper(used wet) to remove the deepest marks(I slipped a couple of times), then 220 grit to clean up the 100 grit marks, and on up to 1000 grit(If you've been careful not to ding the metal up, you can often start with 220). If you're doing a flat guard this is much easier than a shape like this one. Don't forget the edges. As the final touch you can hit it on the buffing wheel to final-polish.
Here I wanted a hammered finish, so I polished it and then proceeded to beat it up. I've got a 4oz. ball-peen hammer with the faces polished very smooth just for this kind of thing. Here I used the peen to work the entire surface, edges and all. Which means I had to do a bit more filing: when you work a piece like this it upsets some metal into the slot. Not much, just a few strokes on each side should do it. Then tap it into place, and there it is.
You can stop here, and fit a grip and pommel to it, or take the next step and either epoxy or solder the guard in place. This does two things: First, it locks the guard in place permanently and second, it seals the space between blade and guard. No matter how carefully you work that space is there, and- especially in a working knife- moisture can get in there. Water, blood, sweat, any of it is bad.
Epoxy is simple. Make sure the surfaces are clean of any oil or buffing compound. Mix your chosen stuff according to the directions. Move the guard down a bit and put the epoxy on the tang, all the way around and up onto the shoulders and ricasso. Seat the guard in place, making sure it's exactly located. Wipe the excess on the blade side off carefully so as not to disturb the fit and set it aside to cure. After it's done, clean off the bottom and tang.
Solder is a bit more complicated but done right it's worth it. There are some low-temperature silver solders out there that work very well for this, generally coming with a tube or bottle of flux. They're lead-free, they stay nice & shiny and they're very strong. The one I used for years is Stay Brite. I ran out of it a while back and couldn't find any, so I decided to try some I found at a local tool store, which has worked just as well. Mind you, not all of them are good. I tried one a few years back- again, couldn't find my favorite at the time- and whether it was the solder or the flux, the stuff didn't work worth a damn. My procedure is
First, make sure the guard slot and tang are absolutely clean.
Second, you can put a bit of the flux on the tang, or put the guard into place first, which is what I do. If the latter, clamp the blade in the vise, tang up, and put a drop of flux on each side of the tang just above the guard. Not much is needed, and if you use too much it will get through the joint and slide down the blade. This stuff is slightly corrosive, and in some steel can slightly etch the surface fairly quickly. Not deep, but enough to leave a nasty drip line on your nicely polished blade.
Third, cut two pieces of solder.
If you look close, you can see the solder in the gap at the edges of the tang, one piece each side. Only small pieces needed; if you've got a good tight join, it doesn't take much. Some put them on each side, I generally put the on the edges.
Fourth comes the torch. Don't use a big flame or put the flame on the solder, heat the tang about an inch above the guard, then the ends of the guard. You want to heat the metal so that first the flux migrates all around the joint, and second the metal melts the solder. This stuff flows at about 430F.
Once the solder flows, take the blade out of the vise and turn it blade up.
I've got the guard sitting on a V-shaped piece of thin steel to support it. Another way is to get a piece of pipe(NOT galvanized) two or three inches long and cut a slot in a inch or two from one end, set the solid end on the vise. Either of these holds the guard while allowing you to play the torch on the tang & guard. The scribe I'm holding(tasteful grip-enhancing tooth marks courtesy of the dog) has a fine round point and is used to 'guide' the solder. When it's flowing freely, assuming a tight and clean joint, you can put the point at the juncture of guard and blade and slide it along; capillary action pulls the solder into the joint, this mainly makes sure it flows evenly all the way around. When you're sure it's done, take the heat away and let it sit a few minutes so the solder can cool and harden. Once it does, you can use the scribe again, slide it point-first along the joint. Do it carefully, and you can shave away any excess solder, making for a neater joint. Remember that if you push too far or it slips, that steel point will gash a line into your polished brass.
Once it's cool, wash it thoroughly with soap & water to get rid of all traces of the flux, then dry thoroughly. At this point I use a dremel with a polishing wheel to shine the guard up, then use something like Metal Glo to clean off the polishing compound, then oil the blade.
*When clamping a blade or guard in a vise, use some leather to pad the jaws, some of the non-marring inserts, just something to keep from messing up the surface.
**A file with safe sides can be a very handy tool. Grind the edges smooth and you can flatten a piece up to an angle with little worry of cutting into the angle. Grind the flats smooth and you can cut the narrow end of a slot without worrying about widening it. Files are inexpensive enough that you can set a bunch up with different combinations of safe & cutting sides.
**Make damn sure the edges are dull. If it's still sharp from the cutting testing and you don't want to dull it, then tape over the edges & point. Depending on the tape, with multiple layers. Otherwise you WILL cut yourself.
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