Zink cannon balls in a Do it cannon ball sinker mold

[smkummer]

OK, here is the story. I bought a repro 1863 naval signal cannon. It has a 1" bore. The "Do it" sinker ball mold is made of aluminum and has 4 sizes 1 oz, 2 oz, 3 oz and 4 oz. The 3 oz. casts about a 15/16" ball and is about right for the cannon. When I first smelt and cleaned the zink, I was able to cast 8 balls before the balls started to not fill out anymore. I upped the temperature with no help. I was using a lyman ladle with a spout on the bottom. I did try pouring slower and I still was getting a unfilled spot towards the top of the cavity. This is similar to when I first started using the buckshot mold with lead, and until I got the mold really hot, they would not fill out. But again, I did increase the temp. with no luck. Any thoughts? Oh and when I cast with lead, the mold worked perfectly.

[country gent]

You didnt give the temp of the zinc but Zinc needs to be at or closer to 1000* to cast and fill out well. ( why holding a pot of lead at 700* dosnt melt the zinc). The first few my be at a hotter temp and pot is cooling from loss of mass. Another is alluminum at zinc casting temps may be doing odd things.

[smkummer]

Yes, I don't believe I am going to deal with it. I tried it again and only the first ball came out round so maybe when the lid if off of the dutch oven, it cools to much. It was going to be a way of simply getting rid of the zink. I poured ingots with it and they came out fine. On recycler will give us .34 per pound in ingot form so its marginal if its worth our time. If I knew some cannon shooters I could send it to and cut out the middle man, then maybe it would be worth the effort.

[country gent]

Another thing to keep in mind that what was once zinc castings are now what is known in industry as mish metal a mixture of aluminum, magnesium, zinc and some other metals blended together. Zinc propely fluved and cast would make a pretty ball though

[Ballistics in Scotland]

That sounds good advice about heating the sprue. But I agree that aluminium heated to zinc melting temperatures is unlikely to last long. They are enough cheaper than large bullet moulds to be worth it nonetheless, if you only want to try it with a few shots. Otherwise I would probably cast from lead alloy. That is a lot of lead, but you are unlikely to be shooting at targets of opportunity in the woods (er... I suppose...), so the chances are you can recover the lead.

[Hogtamer]

I'm reading this with interest as I am going to experiment casting zinc full bore (.730) shotgun slugs with an Accurate mold. A decent full bore lead slug will weigh ~800 grns that means massive recoil. The same slug in zinc should weigh about 580 gr. Since there's some experience here, would pure zinc cast better than Zamak 3' which is ~ 4% aluminum?

[leeggen]

Contact Shadygrady on here and he was exchanging pound for pound zinc/lead.
CD

[Hogtamer]

Guess I'm missing something. You say that Zamak 3 would cast better than pure zinc. Does the bit of aluminum help or hinder fillout? I'm planning on enlarging the sprue hole and pouring quickly with a ladel in this Accurate (iron block) mold. http://www.accuratemolds.com/bullet_detail.php?bullet=73-860B-D.png. Much smaller than 15/16" sphere. Can you give me an idea of what to expect, assuming 800* casting temp? Thanks for your reply.

[Hogtamer]

A zinc penny or 2 in the pot for good luck? Would that bit of copper dissolve and be enough to do any good? Also, soda cans are covered in paint. What to flux with?

[Hogtamer]

Thanks for the advice, you can follow results in The Zlug Thread in the shotgun forum but I won't have the mold for 3 weeks yet.