Sheetmetal questions

[wetzel]

I just received a plank of wood and a 42" rice 45 caliber barrel in the mail yesterday.  I'm going to build a Southern Mountain gun.  On My last build I made my own muzzle cap out of brass and wanted to make one for this gun, as well as the thimbles.  Since this is an iron mounted southern gun, what thickness of iron sheeting should I use for the muzzle cap?  What thickness for the thimbles.  Also, is the process to anneal the sheet steel the same as brass?  My last muzzle cap was one piece.  Can I make a one piece cap by bending the steel the same way I did with the brass?  Thanks for any input on this.

[JCKelly]

Choice of thickness depends a lot on what you can get.

No, you cannot anneal mild steel as you would brass, and no it does not form so well. Mild steel sheet tends to kink rather than bend smoothly.

To soften the steel after it has been cold worked a lot it need only be heated to a dull red, whatever, just do not quench it. Air cool should be fine.

How to bend steel sheet to make a smooth bend rather than one with kinks? "kink" to me meaning a series of bends, not one smooth bend. Someone on this forum should know. Bend it hot should work.

Theoretically - theoretically, mind you - if you lightly tap that sheet all over with a ball pein hammer just before you bend it, it should bend OK/smoothly. If you let it sit around a day or so after lightly cold working the surface it will kink. The metallurgical term is (was?) Lueders lines, and the industrial cure was to very lightly temper pass the sheet, then I would guess keep it in a cool place until formed. The fundamental cause of this forming difficulty is really, really fundamental, but it does not happen in alloys such as brass, silver, or non-magnetic stainless.

Or, for a thimble one could just use black iron pipe, machine or file to the thickness you want, silver solder a lug on.

[KentSmith]

.040 is sufficent and will allow enough "meat" to file in flats if you wish.  You can go thinner but you need to decide if you want flats or other decor filed, worked in.

You don't need to anneal mild steel.  work it at normal temps.  Use a 3/8" mandrel (old drill bit?) or other of suitable size for the thimbles.  I used to use a wooden broomstick for nosecaps until I got a nice metal form from Dennis.  There is probably a tutorial here somewhere. 

This is not that hard to do.  I make all my thimbles from .040 mild sheet sheet or auto body.   And yes you can make a steel nosecap the same as the brass just don't need to anneal it.

[Swampwalker]

I agree that .04 is perfect for ramrod pipes, but because of the complexity of the bends, I would recommend .03" for the nosecap if you can find it.  That's still plenty of metal.  I make forms out of hard maple and bend the sheet metal around that. 
Though I've done several one piece nosecaps out of brass, I've never tried a one-piece out of steel, but used the two piece method instead.  Hey, what've got to loose, give it a try.

[bgf]

You can get 22g steel sheet at Lowe's, Tractor Supply, etc.  It is roughly 0.030" thick.  They also usually carry 16g, which is about 0.060" thick.  The 22g works fine for a one-piece nosecap, just resign yourself to a practice run or two to get the hang of things.  A simple form is easy to make from wood; secure the cap with hoseclamps.  If you go much heavier, you need a lot better setup and might have to work hot to get a one-piece.

22g would also work for plain pipes, but it might not hold much filed detail, 0.40 or so might be better: you can order different thicknesses from TOW, although it is relatively expensive.  For my pipes with flats, I used 16g.  It works, but it is too thick for easy working, and I ended up filing quite a bit off in that application.  The 16g worked well for everything else, though, including buttplate, toeplate, patchbox and even sideplate for what I was doing. 

As said, you don't need to/can't anneal mild steel.  It will work for a long time (long enough to finish a piece rouqhly) without hardening sufficiently to cause trouble, at least in my experience.

[wetzel]

This is just the information I was looking for, thanks for taking the time.

[Acer Saccharum]

Some steels form much easier than others. Old car fenders are one example of a highly formable steel. Look around your junk pile for some suitable thickness. Maybe an old lawnmower, the really cheapo kind with the thin formed metal deck, would yield suitable thickness.

tom

[Swampwalker]

I think the side and top panels on household washing machines are about .03".  These give you a nice flat panel to work with.  You can burn off the paint (outside!).

[David Rase]

In my opinion, making rifle furniture out of mild steel sheet is easier then brass.  Mild steel is malleable and does not work harden like brass so you can eliminate the annealing step.  It does not bend quite as easy but can be formed just as well as brass if you use a little finesse.  I use a lot of .040" and 050" for thimbles, ramrod pipes and nose caps.  I built a mandrel and have successfully formed one piece grooved nose caps out of mild steel with no wrinkles or tears.  There is no need to shy away from making your own mounts from mild steel.
DMR

[dannybb55]

I made my pipes out of whiskey barrel band iron. I cut about three inches off with a cold chisel, heated the middle to yellow and folded it into a U. Next I dropped a 3/8 drill bit in the channel and clamped it shut in my leg vice and with some light hammering, worked the tangs shut. Next I trimmed the edges with my chisel and file finished it. I pickled the pipes in vinegar over night and fire blackened them in oil. The finish is still good after 15 years and should last 100 if my SMLE's is any indicator.

[wetzel]

Hey Dave, what did you make your mandrel out of to form the nose cap?  Did you use the mandrel to form the basic curve and then put it on the gun to swage the ends over?

[T*O*F]

Old car fenders are one example of a highly formable steel

Old being the key word here.  Todays auto sheet metal is high tensile steel.  Back in the 70's there was a steel strike and sheet metal had to be imported from Japan.  Prior to that strike, American sheet metal was leaded steel to provide some modicum of rust resistance.   The Japanese sheet metal of that period was not leaded.  It is also why a lot of cars made during that period did not survive and turned into rusting hulks within a couple of years.  It's also why the guvmint instituted mandatory corrosion resistance warranties from auto makers.  Pre-1970 auto sheet metal is best.............but don't go hackin' up a vintage car to get it.

[David Rase]

Hey Dave, what did you make your mandrel out of to form the nose cap?  Did you use the mandrel to form the basic curve and then put it on the gun to swage the ends over?

Here are a couple of picures of the mandrel I made.

This first picture shows the parts of mandrel.  It is basically a piece of thick walled pipe with a half round 3/8" diameter rod screwed to the pipe.  The slug is tapered and once you lay your metal nose cap blank into the female half of the swage you drive the slug into the unit.  I make sure I have some sort of lubrication on the slug to aid in the swaging process.  The set screws on the female piece are to adjust the position of the slug to conform to different thicknesses of metal.

The second picture is of a completed nose cap.  The whole thing is formed inclusing bending over the nose.

Here is the one piece cap installed on the gun it was made for.

DMR

[Dennis Glazener]

Two things that have helped me:
1. I cut the lip that folds over as close to the final shape/length as I can. Less metal to fold over and less metal to wrinkle up.

2. I use a couple of the heavy screw type radiator clamps to hold the steel around the mandrel. I position one as close below the bend as possible and tighten it as tight as possible.

Works for me.
Dennis

[wetzel]

So you swage the metal over and then file in the octagon shape?  That is a pretty cool little tool you made. 

[David Rase]

Like Dennis said, cut the front as close to final shape as pissible and yes, I swage the front over while it is in the mandrel and then file the flats.
DMR