Copper casting

[ofitg]

Has anyone considered casting cannonballs out of concrete? It may be a brain fart, I've had more than my share.

It might work..... I would worry about the concrete ball breaking up inside the barrel...... ?

A company called "Markwort" sells hollow plastic baseballs for about one dollar each, and they have a 9" size (I think that's the circumference) which might be a good match for a 3" bore. What if a person punched a hole in the plastic and filled the ball with concrete?

 

[CANNONMAN]

HHmmm... Not bad. Concrete can certainly be made to withstand the torment of my cannon. pi x 3" = 9.4. The ball is 9. 0.2 around the edge is a bit much and the stuff will probably shrink a bit. I think it would work! I once mad concrete float to build a breakwater at our marina. It will be interesting to go the other route. Sounds inexpensive. Bet I could add a weight and shoot curve balls! Thanks! CANNONMAN

 

[Pancho]

Reinforcing with a loose ball of chicken wire would strengthen the ball.
The one thing I would be concerned with would be the abrasiveness of the concrete on the bore of the cannon.
I've got a pencil vibrating engraver that could be converted into a vibrator to drive out the air.....or you could use your wife's.
Sorry moderator I hope I made that vague enough.

 

[ofitg]

HHmmm... Not bad. Concrete can certainly be made to withstand the torment of my cannon. pi x 3" = 9.4. The ball is 9. 0.2 around the edge is a bit much and the stuff will probably shrink a bit. I think it would work! I once mad concrete float to build a breakwater at our marina. It will be interesting to go the other route. Sounds inexpensive. Bet I could add a weight and shoot curve balls! Thanks! CANNONMAN

9.0 divided by 3.14 is 2.87........ that should give you about 0.13 inch to spare..... the problem is, I don't know how precise that "9 inch" measurement is. The plastic balls might be slightly bigger or smaller.

Do you normally use a cloth patch with your cannonballs? Like a smoothbore musket shooter might use? The thickness of the cloth patch could make an undersize ball fit perfectly, and it might prevent the bore from getting abraded by bare concrete balls....

 

[Officers'Wife]

If you are really intent on casting a bit of fireclay and a blower and you can use cast iron. Better weight than copper and a lot cheaper. A 3" sand mold wouldn't be that hard to pound up and should last for several pours.

If you have a lathe available my uncle used to use common steel irrigation pipe with a flat metal "cap" welded on, the "cap" turned to size then filled with sand or clay after which a second "cap" welded on and turned.

 

[BCRider]

Yep, I'm thinking that concrete balls or even concrete "conicals" with a patch of old bed sheet and you'd be good to go. If the patches are lightly dampened before ramming home chances are that they would not burn. If so they could be retrieved and used a few times before they wear through.

 

[CANNONMAN]

Why not?

I've looked at the math and it looks like it should work. Concrete rounds that is. I am going to try a 5,000psi with a 3-2-3 mix and add polypropylene stranding for added strength and elasticity. Due to shrinkage and if the aforementioned plastic balls are 9" in circumference, I believe I will cast the balls in a plaster to make a slightly larger ball than filling them would make. [Course ya could say the balls were "jacketed"! HAHAhaha] Since the lead balls shatter when they strike sandstone, I doubt reusing them will be likely. The idea of a damp wad... well I would never do that. There exist a grand old adage, "Keep yur powder dry!"

"There are reasons and there are results. It amazes me how those darn reasons prevent all those results! Or so my kids tell me." CANNONMAN