Creating a custom mold

[Kevin32]

I've acquired a couple mini cannons I hope to cast for.

They're about .860 and .875. I figure a 21mm ball bearing will shoot ok in them. That's .827.

My plan is to order a ball bearing and create a cement form. Put the bearing in the cement and cure it. After curing, split the cement by cutting with an angle grinder most of the way into the cement, and break apart the rest by chizzle. Then drill a sprue in the top with a diamond drill bit.

Though doing some research, it seems some materials risk exploding when exposed to molten lead.

Any ideas or suggestions on how to make a lead mold for my cannons?

 

[BlackPowderBurner]

ball moulds dot com. it'll run you $80 CAD plus postage from the UK to get exactly what you need without messing around and hurting yourself with concrete.

 

[Evanguy]

You can get a real mold easy enough. Or you can make mostly round balls and patch them to get them up to size.

You could use a spade bit ground round in the end and then clearanced for a cutting edge. Grab 2 12" long pieces of 2x4 (dry) make 2 half balls shapes in them with a drill press ever 2". Screw the board together and drill the fill holes into the ball molds

Don't use concrete

 

[Dogleg]

Round ball is pretty easy, high temp silicon and youtube will fix you right up.

As an aside, if anyone knows someone who will cut custom jighead molds they would have my undieing gratitude.

 

[Splatter]

Concrete is not a good idea because once it is cured, water molecules are bound in the structure of the matrix. When exposed to high heat the water will separate, often producing cracking and flaking, usually known as "spalling".
It's not going to explode, but it probably won't be much use after the first time.
I've never used the high temp silicone; but I've seen a few vids on it and it seems like a great choice.

 

[rginbc]

If you are.going to cast. Use casting sand. Concrete or cement may explode.with disastrous results.

https://www.ballmoulds.com/?fbclid=...9_YDdEh6g3H4mBVRqg_aem_WuGBYNCcPlH2bljyigTxdg

They ship to Canada. Hope that helps

 

[Snider shooter]

Accurate moulds does custom orders.

 

[Mr Bill]

The boys in the farming neighbourhood would fire off a cannon for special occasions. The projectile was a can full of water that was frozen solid. Black powder wrapped in aluminum foil and toilet paper for wadding. The Cannon would roar, but the frozen projectile would shatter and disintegrate within 100 yards. Quite safe, my house hasn’t been hit yet. Never bothered to calculate the BC or chronograph the velocity. Accuracy was MOB (minute of side of barn)…

 

[Snider shooter]

We had a fellow here that filled beer cans with cement and fired out of his. At 100 he could pick where he was going to hit the barrel. Worked well. Always wanted one that took golf balls.

 

[DFarmer]

We made one for round fishing weights out of Bondo. It lasted for a while.

 

[Kevin32]

Turns out 2oz fishing weights are the perfect fit! No need to create the custom mold. Finally I can order bullets on Amazon, lol.

 

[unstableryan]

I think I want a golf ball diameter one.

 

[boxhitch]

Ready?.....Standby.......FORE!!

A cannon here shoots tomato paste cans loaded with concrete, about 50? mm iirc
Lead is too valuable to waste away

 

[boxhitch]

Any ideas or suggestions on how to make a lead mold for my cannons?

I'd use fishing round balls but for a mold i'd find an existing bullet/shot mold and have it milled out to size