Brass Barrel Making

[Backswampcub]

        I am dabbling in the world of backyard metal casting with one goal in mind. I would like to cast a brass or bronze barrel. My goal is to cast all the metal parts for the carriage too. My question for all the barrel makers out there or metal casters. Can I use my Mauser and other ammo casing or is this not a high enough grade brass. I am thinking that it is and I can get a lot of casing. I will either be turning a wood cannon pattern or I may use my GB Naval barrel. Can I cast a steel liner into brass or bronze. Any thoughts or brainstorming on this would be appreciated. Thanks

[KABAR2]

You really want to stay away from Brass for cannon barrels, it will be fine for carriage parts but brass is too brittle for cannons, Bronze is the way to go.
Also an unknown is what the corrosive powder residue has done chemically  to the brass or what various metal content is in the brass.

[Victor3]

 I think if I were to go through the ordeal of casting a bbl at home, the cost of the material would be a secondary concern. Metal prices have gone down recently, so getting some bronze should be less expensive than just a few months ago.

 I assume what you have is some kind of milsurp 8mm (Mauser) brass? If it were commercial boxer-primed stuff, you could sell it on ebay and use the proceeds toward some bronze.

 Also, you're going to need a lot of cases; I just weighed a milsurp 8mm Mauser case to be 9 grams. Assuming your golf ball bbl will need 50# of material, that's roughly 2500 cases...

[Cat Whisperer]

I agree with using bronze on the barrel.

On the other side of the coin, for other pieces, the brass used for shell casings is known by name as cartridge brass.  It is of course unknown, but the SMALL samples that I've had analysed were true to the ratios published.  I've got several cubic feet of empties and another couple of cubic feet of copper blocks.

SOMEDAY ....

[dan610324]

put out an add in your local paper that you want to buy copper scrap , but only use the kind of copper that have been used for electric purpose .
everything else aint pure copper , its alloys and you dont know whats in it . so pipes and similar things that looks to be pure copper it aint , and it can totaly ruin the strength of your bronze alloy .
tin you can never be sure of if you dont buy pure virgin tin , most others contain lead and antimon .
the most used bronze for cannons is 90/10 copper/tin

but please dont use brass

be sure you have minimum 1 cal in wall thickness of your finnished barrel in the breach area .
preferably a little more .
it aint any big problems to cast the cannon around a liner . but you must tin cover the liner before the casting .

please tell us some more about this project .
size ??
style ??
sand casting or lost wax ??
what possibilities do you have to check temperature on the molten bronze ??
you should avoid having an to high pouring temp , if its to hot you will have gas blisters in the casting .
if it aint hot enough it will not fill the mould, so the best temperature depend on method and size of the object you want to produce . its also very important to have the right mould temperature when pouring .

[Backswampcub]

              I can get my hands on copper. I believe that plumbing fitting are pure too. I am looking to cast either a naval or Swivel gun. I am looking at sandcasting as my choice. I have not seen the wax type you are refering to. I have a laser temp gun for bronze temp. I am feeling things out and getting input from everyone here to see my next course of action. I can and have done anything that I have put my mind too. I am going to make this work and safely. So it looks like I will be saving the brass for some other project. Thanks

[dan610324]

remember that all beautiful antique cannons you see today is cast with the lost wax method .
sand castings give an low finish result if compared to lost wax  casting .
sand cant show extremely small details , wax do .
but it all depend on what model you want , how much details it is .
lifting dolphines or not , and much more .
but I would recomend you to start looking for information about lost wax casting .
its an completely new dimension in casting if you are used to do sand castings .
at an high quality lost wax casting you can produce details so small that you cant see them without an magnifying glass . this is the method used to create all high quality jewelries

[Terry C.]

I have not seen the wax type you are refering to.

The reason it is called "lost wax" casting is that the master, which made of wax, is burned away as the mold is fired. The wax master is coated with a ceramic slurry. The consistency of the slurry depends on the work. A fine slurry is best for small intricate parts, while large heavy items need a thicker, coarser medium that will build up thick and strong. After the mold has air dried it needs to be fired, and this burns away the wax leaving the mold cavity.

Once the pour is made and the metal has cooled, the mold is broken off.


Modern investment casting is based on the age-old lost wax method. "Investment" refers to the fact that a new wax master and mold is needed for every pour.

Investment casting can produce raw castings that require very little finishing. Many gun manufacturers (Ruger was the industry leader) are replacing machined forgings with investment cast parts.

[GGaskill]

I have a laser temp gun for bronze temp.

Bronze needs to pour at around 2075°F for ceramic shell investment casting which is too high for my Raytek to measure.  Don't know about your model.

[dan610324]

dont be so sure that plumbing fittings is pure copper , and if its scrap there are some soldering material also , it will result in an alloy you dont know what it is .
try to find pure electrolyt copper scrap .
only use virgin tin.

[Backswampcub]

       So this is what I have been able to formulate as a plan of attack on this cannon. I am going to still make a wood cannon pattern. I am then going to coat this with oil or vasoline and plug bore. I will then suspend it flat in a box. Then I will fill the box till half the barrel is covered in plaster,allow this to dry then grease up the barrel and plaster face. At this point I will fill the box rest of way with plaster, let dry split two halves remove Pattern. Place halves back together. Fill with wax let cool. Then clean up my new wax cast barrel carve in any fine detail and such.The wax cannon is then coated with a ceramic slurry sprinkled in sand allowed to dry slurried again sand coated again till desired thickness is met. Allow to dry when dry heat up the wax insid the cast with a torch or in an oven to remove wax. after wax is removed. The cast will need to be fired in a kiln. This is the point that you would be ready to pour bronze. The mold will have to be heated up with a torch before pouring bronze in. The reason for the plaster mold to make the wax cannon is to allow you the ability to reproduce the same barrel over again . Instead of recarving one each time.

[dan610324]

I wouldnt use plaster to make the mold for the wax casting ,
I would use 2 component liquid silicone rubber

then I would use an high quality investment instead of the ceramic slurry .

ceramic shell need chissels and sand blasting to clean up the casting ,
investment you clean with an hose and running water , or just dip it in a bucket with water and the investment will disappear .

but its important to have an special kiln for the investment mold to have the burnout process of the wax perect . and pour the bronze when the mould still is at approximately 400  450 degrees celsius .
temperatures differ slightly from manufacturer to manufacturer .

if you pm me your emailaddress I will send you an complete serie of pictures showing how I make an silicone mould for an lifting dolphine .

[dan610324]

I just emailed the pictures to you
but now its almost 3 am here so its time to go bed   

[GGaskill]

You're also going to have a shrinkage between the original and the finished product.  There will be shrinkage in the wax and shrinkage in the metal.  Combined maybe a half inch per foot.  It would be best if you make the wax pattern hollow so that it can expand into itself when the wax is heated inside the investment.  Unfired investment is not very strong and a large solid wax pattern can expand enough to crack the investment while dewaxing.

[dan610324]

I use to put the unfired investment upside down over boiling water to dewax the mould with steam before the real burnout process .
I use old candle stumps instead of real casting wax , get them for free from the town church .
guess I have a few houndred pounds of them now . the melting temperature is 58 degrees celsius .

if you heat the silicone mould to 55-60 degrees celsius and have the molten wax at approximately 70-75 degrees celsius you get almost no shrinking on the finished wax master .

shrinkage of the bronze is approximately 1,6% .