Fabricating: Trench Gun heat shield

[Lutso]

Hey guys. Sorry if this is a little off-kilter for the RPF, but I would rather ask questions about fabricating from the folks here than on the gun boards.
(If this sort of thing is not allowed, mods feel free to remove with notification).

I have a Modern 12ga. scatter gun that I am converting into a WWII-style trench gun. I am modeling it off the Winchester 1912 for reference. So far I've got all stock and body parts covered, and it is really looking good. However, it's time for me to start thinking about adding the iconic heat shield to the barrel...and there in lies my trouble.

I simply will not settle for the heat shields that are currently sold to work with modern shotguns, as they look like crap and are not of the right length or fitment for what I want.

Here is what I am trying to replicate (shield section only - not the bayo lug):

Since I will not shell out 30-60$ on a stock shroud that I don't even like to begin with, I've started entertaining the idea of fabbing it.
Keep in mind this thread is only concerned with the perforated (shroud) portions of the assembly.

I have two ideas;

My first option is to buy a sheet of perforated steel or aluminum, cut it to desired length and width, and roll it into a half-tube to sit atop the barrel. However, purchasing cuts of perf sheet from vendors such as onlinemetals.com will leave me with unfinished edges (i.e., partially-cut holes creating "bumps" along the permeter of the sheet). I can't have this. There needs to be a smooth margin around the perimeter of the piece for this to work.

My other idea was to get a length of perforated tubing and simply cut it in half length-wise. However, this poses the same problem as the first in that I will inevitably be left with rough edges and partial holes as the perf pattern will not line up.

Not seeing a way to get around these problems, I came up with a design for a custom piece of metal (measurements are rough until I can get some accurate measurements from the gun); a piece of steel or aluminum 14" long and 3" wide, with 3/8" perforations, staggered, with a safety margin of 1/16" along all edges.
However all the prices I've found so far to get this made have proven to be an absolute fortune. I thought it seemed like an easy enough thing to make, but I guess not.

What do you guys think I should do? How would you tackle this if you were in my situation?

 

[nomuse]

My thoughts are drill press, then get access to a brake....but it is going to be really hard to beat $30. If you can get a proper one for that little...

 

[GrenadeKing]

I'm rather jaded toward machinists. In most cases your paying for their time or for time on the companies machines. Your not paying for your part.

As for how I would do this, I'd find a piece of tubing (I'd do aluminum because it has great heat dissipation and is easy to work) then, I'd get on my trusty computer and make a template for the design. I'd then print that out and glue it to the tube to use as a cutting/drilling guide. I'd get a drill press and I'd drill all those little holes, then I'd cut off the excess.

That's how a lot of folks here make stormtrooper blasters and lightsabers from pipes and sink tubes. Seems to work well enough.


The easiet way would be to buy a modern repro but, I realize your talking about the Model 12 and not the 1897.

 

[Lutso]

A drill press is a bit of a stretch for me. Do you think it could be done with a hand drill? That would be a grueling project...ugh...

 

[dangerstudios]

Looks to me like it could be done with styrene.

 

[ewokus]

Go to a water-jet cutter, they can do it for you. If you can design the thing with any kind of graphics program, then you'll get exactly what you want, 'coz you designed it. Once the cutting is made, simply roll it to the dia. you need to fit your weapon.

 

[Gorgot3000]

print the template of the holes on a sticker sheet , put it onto a half plastic pipe ( like plumber pipe ) cut it in half , and if you center your drill bit ( use a very small one to begin ) and you maybe good to do it with hand drill

 

[TK1961]

I'm rather jaded toward machinists. In most cases your paying for their time or for time on the companies machines. Your not paying for your part.

As for how I would do this, I'd find a piece of tubing (I'd do aluminum because it has great heat dissipation and is easy to work) then, I'd get on my trusty computer and make a template for the design. I'd then print that out and glue it to the tube to use as a cutting/drilling guide. I'd get a drill press and I'd drill all those little holes, then I'd cut off the excess.

That's how a lot of folks here make stormtrooper blasters and lightsabers from pipes and sink tubes. Seems to work well enough.


The easiet way would be to buy a modern repro but, I realize your talking about the Model 12 and not the 1897.

:thumbsup what he said.

 

[TK1961]

Oh and get a step drill bit, works great.

 

[Lutso]

Go to a water-jet cutter, they can do it for you. If you can design the thing with any kind of graphics program, then you'll get exactly what you want, 'coz you designed it. Once the cutting is made, simply roll it to the dia. you need to fit your weapon.

I've NEVER heard of a place like this. More information? Where can I find a place like this, and how do I look it up?

Granted that doesn't work out, it looks like I'm doing it by hand with a step bit. Can't wait to do each individual hole...yippee. If I get one of the 50 holes off by a tad, it could ruin the whole thing...but no pressure, right?

I'll use a flat strip of metal because I don't want to get into drilling on curved surfaces again. Not a fan.

Thanks for all the suggestions guys, you've really helped.

What are thoughts on shaping the metal? I figured I would form it over a piece of pipe with a mallet. Is that a bad idea?

 

[mbwelder]

If the steel is thin enough, forming it over a pipe won't be a problem as long as you clamp it at both ends with a common centerline on the pipe. I would hate to drill all of those holes with a hand drill myself, as larger holes in sheet metal tend to bind up, but a step drill should work. My advice, should you go the drill route, would be to layout all of your holes, centerpunch them all and drill while the thing is flat, then form it over the piece of pipe.

No matter which route you go, there will be some finishing work involved.

 

[OdiWan72]

Transferring the template/ holes to a tube or even a cut down half tube wouldn´t work in this case gentlemen!
Take a closer look a the heat shield...it´s not a simple half pipe, but more of a "U" with longer straight sides.

Listen to what mbwelder said:
- get some thin steel or aluminium
- transfer the template/ cut the holes/ shape the fron and rear end of the shield
- clamp it down to a piece of metal tubing with the correct OUTER DIAMETER
- bend it/ hammer it to shape

Markus

 

[Lutso]

shape the front and rear end of the shield

Markus, what do you mean by this?