The polishing of metal for firearms is essentially the same for all metals if you're doing the work by hand. Some will claim that you've got to have a bunch of power equipment to polish metals. In trained, experienced hands, large surfaces can be done this way. But, to do detail work or surfaces intended to be rust blued the old way, or maintain all the corners and keep the surfaces true to profile, the very best way is to do the work by hand.

Hand polishing is easy but requires patience on the part of the craftsman and a connection between the eyes, brain and hands.

Work can be divided into two basic classes, one of which follows the other generally: 1) Shaping rough parts to the desired final shape and 2) Polishing the parts to the desired final finish.

We will talk about tools and techniques and also mix in a little of my philosophy and opinions.

What you're doing is sculpting metal. Look at a nice Lancaster trigger guard. Then look at the side of a 1911 Colt auto. It's still sculpting; one has lots of curves and surfaces the other is flat. If there is a minor variation in the shape of the trigger guard it probably will blend in with the curves; if the Colt is not really flat, you'll see it instantly. So which is harder to do? Doesn't matter because you do both the same way.

Assume you start with a casting for the trigger guard and assume you know what shape you want the finished article to be. Start with files; sharp files. Here's the rules for files: Never let a file touch anything except the material you will use it on or softer materials. This means that the files you will use on wood must never touch anything harder than wood. Files for brass must never touch steel, etc. If you doubt this, take a new file and spend some time filing the side grain of maple or walnut. Notice that if you cause the teeth to make a slicing cut you will get little curls of wood like a plane. Now take that file to a brass part and file for a while. Notice how it bites in and cuts little curls of brass. Nice. Now take that file to a piece of mild steel for a while. Cuts nice doesn't it! Now go back to the wood. Just sort of rubs it, doesn't it? No nice clean curls. Now try the brass again. Doesn't bite well anymore.

Buy new files for the intended materials and don't use them on anything else. When the files for brass start to get dull, move them to use on steel. When files for steel are dull, make knives out of them. All files must have handles; how the heck else can you get a grip on it to control it!! Buy wood handles with metal ferrules; the kind that just have a little hole in the wood to press the file tang into. Buy one handle for each file. Mount it firmly by driving the file into the hole but don't split the handle. Once you have the handle mounted keep it on the same size tang. You can remove it by putting the file against a block and pulling the end of the file so the front of the handle catches against the block and is knocked off. Handles that screw on will screw off while you are trying to hold the file in the roll axis.

A file is a cutting tool. A bunch of them on one surface. It cuts in one direction. A file is not for rubbing with; it's for cutting with. Cut in the intended direction, lift the file and make another cut. Use two hands; one to hold the handle and one the other to hold the end of the file. Locate your work so you're not scrunching your body into uncomfortable shapes to work. Take deliberate cuts without pushing too hard. Notice that you can move the file across the work at different angles while the file is still pointed directly away from you. Kind of a swiping motion. Notice that the file teeth are at an angle to the axis of the file. Notice that the swipe direction will change the angle of attack of the teeth on the work surface from a plowing action, in one direction, to a shearing action in the other direction. You can make this work for you and the swipe angle will be different for different materials and hardnesses. You don't have to push the file straight away from you! It's a tool; understand it and control it.

Every stroke or two take the fingers of the hand holding the end of the file and 'wipe' the teeth from the tang to the end. This will help remove the filings from the teeth and prevent gouges. For really fine work rub a soapstone or chalk into the teeth to minimize filings sticking in the teeth.

Use the coarse files, bastards and second cuts in that order, to rough out the shape and smooth files to finsh with. There are hand files, mill files, kant files, half rounds, rounds, three square and a lot of other shapes. Files run from 4" to 14" long (the length not including the tang) and the larger sizes have the coarser teeth. Most decent machine shop supply stores will have good, American made, files from Nickleson, Lenox or Simmons. Call around your area to find someone with a good stock. Ask for a catalog covering the file company they buy from. Or all of them. The catalogs will have pictures and explanations of the files. Most stores will ship UPS. If you can, go to the store and select your own files. Check that the teeth have not rubbed other files (look for bright spots on the tips of the teeth) and make sure that the files are flat and straight. All files have some curve but a flat file should be _very_ flat! Sight along the files to check.

Use files to generate the shapes and surfaces you want to have. You will find that you can produce nice clean, smooth surfaces with a smooth mill file.

Move the file to follow the surface you want to create. For roughing out curves it's useful to work the part symetrically, both sides at once, in a manner similar to creating a round from a square: 4 sides then 8 sides then 16 sides, etc. This allows you to watch and control the shape as you produce it. Make the final smooth curve after you have roughed out the whole part. Don't try to put a good finish on a surface next to one you haven't roughed out yet. Sure as heck you'll slip with that big bastard and muck up the nice surface!

Work deliberately and with a clear vision of what shape you want to produce. Have the part in a vise and light it so that you can clearly see the light from the surface you are working on. That's a big part of metal finishing; you don't look at the surface but at the light reflected from it. As you refine a shape and use finer files you need to know that you have removed all of the tool marks from the previous tool. You do this by adjusting your lighting so that there is a contrast between the old tool marks and the new. You can't see the exact spot your file touched if you cut in the same direction all the time. If your light is right, and you cut at, say, 45 deg. from the last pass, you will clearly see the contrast between the two cuts. You can do this with each stroke of the file and see exactly where each cut touched. With practice this is the technique you use to file perfectly flat surfaces. Just rubbing a file across a surface won't make it flat. You have to make it cut exactly where you want it to cut.

For curves, your eyes will tell you what the curve wants to be unless you have a gage or template you are trying to match. Use a straight edge to gage flat surfaces to see where the high spots are. Almost all files, no matter how well made or selected, will have some curve or bow to them. Know what that is and use it to your advantage.

With practice you should be able to produce smooth, blemish free surfaces that are as good as 220 grit.

Well, how to polish the part????? Get some rolls of 3-M abrasive down at your machine shop supply store; 220 and 320 grit is all you need. This stuff is dark brown or dark grey and 1 1/2 or 2 inches wide. You will also want some 400 and 600 grit wet-or-dry silicon carbide paper from 3-M.

If you have generated a nice smooth surface with the mill file, start with the 220 grit. You will now, again, file the part but instead of the file doing the cutting, the abrasive will do the cutting. Tear off a piece of abrasive about three inches longer than the file. Wants to be long enough to fold over the end of the file about an inch so you can hold it with your fingers. You will likely want to tear the strip down the center so it's the same width as the file. Use a fine point marker to mark the grit on the back of _each_ piece of abrasive!! Keep the different grits separate! Nothing will ruin your day faster than getting a 220 grit scratch across your 600 grit surface. On that subject, develope the habit of keeping your work area clean and tidy so you're not banging files and abrasives together.

Work the part with finer abrasives paying attention to not round off corners or change the careful sculpting you've done. Use the 400 and 600 grit wet and use wood (tongue depressors, popcicle sticks) instead of files for backing. Use the correct lighting to allow you to see each stroke of the abrasive and make sure you remove all the marks from the 220 before going to the 320, etc. Remember to stroke at different angles so you can see where you have been and make sure you have removed all the coarser marks. Notice that the well worn 220 will act like a much finer grit. Use this to your advantage as you finish off with the 220 to approach the 320 finish.

Do the same with all of the grits.

This will save on the amount of abrasive you use and that stuff is not cheap!

If you want a mirror finish, use a strip of cloth and Brasso on a stick.

WOW!!

General:

Most brass castings are fairly straight but most will also require some straightening to make them truly right. Buttplates are sometimes twisted or need to have the angle adjusted. Trigger guards are the worst as most are not straight along the axis and require twisting and bending to get them to bow right. Study the heck out of what you are going to do before you start bending!! Trigger guards are especially hard to judge because the real shape isn't obvious until you have filed out the symetry some. Don't just file without seeing if the casting is straight to start with. And don't start bending without know what it will look like when you've finished. Pay attention to how you hold cast parts in a vise; you can squeeze them out of shape very easily. Castings made from quality yellow brass can be bent, but don't ever bend one back and forth 'cause it will break. Bend gently. Never try to bend hot. You can anneal the casting but this will leave it too soft for service. If it's that wrong, you've got the wrong one. Go get one that is the right shape.

I use sand castings on most rifles because they have enough 'meat' to allow me to custom shape each one. Hey, they're custom rifles, right?

Buttplates:

Hold the plate in your hand to smooth off and true up the part that will touch the wood. It doesn't need to be polished, just made into a smooth surface that you can fit to the wood tightly. You can rough file the top this way also, but I find it easier to fit the plate to the butt and then do the filing on the exterior of the plate. I do this as I'm preparing to shape the butt stock.

Trigger guards:

I use a filing fixture made of aluminum plate and milled to hold the mounting tabs of the trigger guard. You can buy this type of fixture from Golden Age Arms, 115 East High Street, Ashley, Ohio, 43003. This fixture will hold any guard that is tab mounted like Pennsylvania rifle guards. If you modify the fixture so that the curved 'swoop' in the center is square, with one side parallel to the long outside side (!), you will be able to hold the fixture in your vise flatwise to work on the curves at the front of the guard where the bow meets the foot.

Use wood jaw inserts in the vise to hold the guard so you can shape the feet and the tabs. Shape and size the tabs to fit the slots in the fixture closely. Try to have the tabs be in the exact center of each foot or base to make inletting easier. Leave the tabs full length until you know exactly how deep it needs to be.

Hold the guard in the filing fixture to do all the other filing and polishing, moving the guard in the fixture as necessary to reach all the areas.

© 1995 P. D. Krogh