Antique Cannon Construction - Sage Advice Needed

[nhmoose]

I would not be near any that are not steel lined using a barrel steel

 

[Big Al1]

Two things ..Can anyone tell where I can a large enough lock for a punt gun I am building.Also where I buy a 5 ft smooth barrel?

 

[cw1873]

Okay, so looks like I misunderstood the process! So, what you're saying is that the metal was poured into a two piece mold, and then the cannon was taken out in one piece, and the seams are there because of the two molds, and not because two pieces of metal were joined together? If that's what you mean, I can understand that.

I misunderstood the guy in the video as well the first time. He is using the wrong word, seam, when he means flashing. Ordinarily this kind of mix up wouldn't be a big deal, but in this context, it makes a big difference.

 

[DavidG.H.]

Thanks cw1873! I wonder why the people who cast the cannon didn't remove this flashing? Seems like it wouldn't be a big deal to spend some more time on this and just grind it down?

 

[Canute Rex]

About Dahlgren and Rodman:

Dahlgren innovated the non-decorated "soda bottle" shaped cannon in the mid 19th c. He realized that the decorations on earlier cannons were potential fracture points and that the mass of iron should be towards the breech where the highest pressure was.

Rodman realized that the standard casting method had the iron cooling from the outside in, making the cannon softest at the bore and hardest on the outside - the opposite of what it should be. It also induced stresses in the iron. He invented the method of casting the cannon with a water cooled core. This reduced stress and gave a hard core to the cannon.

The result was a class of Dahlgren-Rodman guns of extremely large caliber and power.

 

[Rich44]

When you would like to lean more on a subject matter we get in the habit of just "google it". And sometimes a youtube video can also be found. But this can add to the problem because how do you know that the information is correct and or being explained so a person can learn. Just picking one video out and then using that as this must be correct has let downs.

Here are two links that may help to explain. Both are excellent.

 

[ChrisPer]

An alternate method of casting which does not use a two-part mold is lost wax casting. This is also the method used since antiquity for bronze sculptures as it was one of the earliest advanced technologies of any civilisation.
The advantage of lost wax is that extremely high quality finishes can be made, on parts that are fully 'in the round' and with undercuts.

Careful mold-making can create multiples of the wax model, in which case any 'seam' or parting line can be sculpted away before 'investing' the model.

I really don't have special knowledge of gunfounding but would love some references that show all early methods.

 

[Captndan]

Buy only a modern tube from a reputable dealer like South Bend Replicas which has the barrel cast solid, drilled, and lined with a steel liner which has been fitted and welded with a steel plug. Get a copy of the More Complete Cannoneer, by Matt Switlik.

Good advise here. Decide what you really want. A signal gun that only goes bang or a real one that fires a projectile. Original barrels are hard to find and are expensive. Also not as strong as the modern day barrels. So, if you want the real thing that shoots a projectile go with a modern day.

 

[furryjohn8084]

Interesting piece about signalling cannons. I picked one up at a car boot sale two years ago for the princely sum of £4.00, about 5 bucks for those on the other side of the pond. It seems to have spent many years in a chicken hutch, and it took some time to clean it up, turned out to be about 3/4" bore, 10" long, and a wall thickness at the breech of about 1/2". Fairly nice little oak carriage, too. Would I shoot it? Yes, but only a blank charge of about 50gns of f or ffg, and a slow fuse so I could get behind something solid... There's a lot of decorative ones around, but most have no touchole. Little trick you might try. Party poppers have a small detonator in them. One of those taped over the touchole, with a pinch of ffffg works well. And it's easy to fix a longer string. The alternative is one of the modern shooting replicas in .50" or .69" I think. Definitely safer. But if you know a good engineer, he might be able to make, and fit a mild steel barrel liner. Fit it with epoxy, or soft solder. Depending on walk thickness, you should by okay. But, again, long string, or fuse. Have fun..

 

[DC Brown]

Howdy fellas and gals! I am interested in purchasing an authentic antique muzzleloading brass or bronze signal cannon for my man-cave, as I've never bought one before, but always admired them!

Could you give me some tips on what to look in terms of authentic construction, in an authentic Eighteenth or Nineteenth Century brass or bronze signal cannon?

For example, I have read that the authentic antique ones will have a core of iron, and so they will be somewhat magnetic, even if they are brass or bronze.

Also I read that the very old ones were actually cast in two pieces and then put together, so you can see a Seam running across them. In other words, if there is a Seam on the cannon, you are assured of having a good one that's 200 years old!

Are these correct assumptions? Any other things to look for?

Gratefully yours,

David

 

[DC Brown]