Tips for Shaping Brass

[John Walling]

Can anyone point me to some videos or offer some advice on finishing rough cast brass? Picked up an old Replica Arms kit gun that needs all the brass worked down and woodwork finished. Woodwork I should be good with but yhe brass is something I've never ventured into before. Thanks.

 

[Phil Coffins]

I use files of different types then sand paper with a backing. The backing for sand paper is critical to doing a good job.

 

[John Walling]

Any specific kind of files? I've been thinking of getting a new set of files and rasps since I have some projects coming up that will require some more intricate shaping work.

 

[Zonie]

For most of the rough cast surfaces, using sand paper will do the job.
Not ordinary sand paper though. The "flint" or "garnet" paper is made for sanding wood and it works rather poorly on metal.

The "Wet/Dry", black colored silicone carbide sandpaper in the rougher grades is made for use on metal and it works well. Like the name says, it can be used wetted with water or dry. For the real rough areas look for 80 or 120 grit. After the roughness is removed, switch to 180 grit, then 220 grit and finish up with 320 or 400 grit paper. You can go to finer grits but the paper finer than 1000 grit won't do much of anything. The 1000 grit and finer ones is really made for doing the final sanding on auto body paint.

I aught to also say, 3M's red, "Pro Grade Precision" works well with metal as well as wood, plastics and darn near any other sand-able material you can name. It's really good stuff. It is supposed to be used dry only.

 

[Phil Coffins]

My files are mostly common types with few special ones to include needle files and chain saw files. A 8” mill bastard and a three corner file with one side ground smooth can be bought anywhere. These allow you to quickly remove the parting lines of the castings and keep both inside and outside corners crisp as well as flat surfaces flat. Sandpaper grit coarser then 150 doesn’t allow me to do my best work and I get rolled edges. Form with files and sand for finish. Avoid Dremal tools.

 

[Col. Batguano]

I usually stop at 600 grit on brass to give it a "brushed" look, or maybe 800. 4-0 steel wool is pretty close to that too. Going finer than that will make your brass shinier and shinier, and it will take longer for it to dull toward that "aged mustard look" that we all associate with the original guns.

 

[John Walling]

that "aged mustard look"

So I have never heard that phrase before but that is the truest statement I've ever heard!

 

[Barry Strickland]

John, one of the first things you should consider is filing the mating surfaces on the trigger plate for a nice tight fit. Then, as mentioned use a wood or file backer on the sandpaper. Also you will find dowels of different diameters make a good backer for the concave surfaces. Keep us posted on your progress.

 

[John Walling]

I thought of using dowels and cutting square blocks for flat surfaces. The trigger guard is atrocious right now. PO already jacked up the front screw holding it on. I assume he didn't know a kit gun required fitting everywhere, lol.

 

[Pete G]

Use your files only on brass. Once used on steel they are not good for brass. Most builders keep separate files for different uses.

 

[John Walling]

I wondered about that too. All my files have been steel used. Always looking for a new excuse to buy more tools. Can brass and wood files be interchanged after leaning them up?

 

[Col. Batguano]

You'll want sharper teeth on your files to work on wood than you need for metal. Brass has a tendency to bend over and swage, unlike steel that cuts off cleaner. Though you CAN use your metal-used files on wood, the results won't be as good, and will definitely take longer to achieve.

 

[stewart.leach]

A good supply of "patience pills" is a good thing to have on hand. What I mean is, go slowly, don't rush it, take your time to work the metal in the best directions. The process will go better if you have some wood jaws for your vise.

Two files I like to get new for each rifle are a fine round rat tail and an ignition point file from an auto supply store.