Author Topic: cast lead projectile idea (Read 718 times)

CU_Cannon · « **on:** January 12, 2005, 08:12:08 AM »

How about using a plaster mold to cast lead projectiles?

My brother-in-law did some bronze castings in college. He said to use a cardboard milk container and fill it about half way with plaster and set some golf balls (or any other size ball) sticking about half way out. The balls should be coated with transmission fluid so they release. Once the plaster hardens coat the top surface with more transmission fluid and pore more plaster on top. When the mold dries the milk container can be peeled off and the mold can be separated. He warred that the plaster needs to be very dry. It should be baked in the oven for several hours just before you cast. The mold can then be reassembled and pored.

It seams like it would be a relatively easy way of getting any size projectile you want. It would be a one time use mold but it would be cheep and easy to make. You could cast as many projectiles as you could melt lead for.

Any ideas?

CAV Trooper · « **Reply #1 on:** January 12, 2005, 08:55:06 AM »

Interesting idea. I know, from seeing it done in college, that a plaster mold will work for casting a ball. However, every time a friend of mine used to do castings (not cannon balls) the mold was for a distinct item that was one of a kind. Using plaster molds to go into production has a downside to it.

Since each mold can only be used to cast one ball, you'll be making a lot of molds which, in the long run, will be both time consuming and costly. While plaster doesn't cost a whole lot by itself, you have to figure in the time (and other materials) you'll spend making the molds before you can actually pour a ball. To me anyway, it seems much more cost effective (in time, materials, and labor) to simply use a steel or aluminum mold.

CU_Cannon · « **Reply #2 on:** January 12, 2005, 11:01:40 AM »

You could make the molds with several cavities. Using golf balls and a milk container you could probably cast 4-5 balls in one mold. The most efficient use of this type of mold would be to make a lot at one time.

I'm not sure that it would take that long at all to make the mold. The most time consuming part would be the actual mixing of the plaster. You can mix the plaster, pour it, let it dry for a day or so, come back and do it again for the second half. I can't imagine that it would take much more than an hour for each part. If you make several molds at once the time per mold would be at a minimum.

CAV Trooper · « **Reply #3 on:** January 12, 2005, 02:36:47 PM »

For some reason, I was picturing just one ball per mold. Multiples would definitely cut down on the time and labor. Sounds like a plan. Give it a try and let us know how it goes.

Cat Whisperer · « **Reply #4 on:** January 12, 2005, 03:18:12 PM »

I tried that before I was a teenager. I'm sure that I'd do better now.

Make CERTAIN that the plaster of paris is DRY. It does come unglued fast when damp - steam.

CU_Cannon · « **Reply #5 on:** January 13, 2005, 02:46:07 PM »

Dry is a must. Pop corn comes to mind but in this case it would be hot plaster and molten lead flying at you.

Another idea is to add some sand to the plaster to make it a little stronger.

Once I have a chance I'll try it out.