Casting Lead Balls

[armorer77]

Hi , I have just had a ball mold made , I didn't know what size to drill the sprue . Anyone who is already casting lead , a little help please ? The mold is 1.690"  for GB size cannon . Thank you .

[seacoastartillery]

     We have two .985" lead ball molds for our 1.000" dia., smooth bore, 1/6th scale, 100  Pdr. Parrott Seacoast and Navy Gun.  The sprue size on both is .167" and they fill very quickly.  If you had a little larger sprue dia., say .187" (3/16"),  your lead golf ball mold should pour quickly without any premature freezing at the sprue plate.

     What type of cannon do you have?  Any photos of it available?

Good luck to you,

Tracy and Mike

[armorer77]

Actually I already cut .187 dia.  To avoid any confusion I have been casting bullets for over 25 years . The new mold was made by an engineer who makes plactic  injection molds . My initial clean up proved the mold was tight , perhaps too tight ? I cut an air vent .005 by .250 wide , pre heated the mold . I don't have a pyrometer so I can't say exactly how hot .  I do have photos of the cannon , I pulled the Boat Howitzer plans from this forum . I have made 3 . Thanks Armorer

[intoodeep]

I do have photos of the cannon , I pulled the Boat Howitzer plans from this forum . I have made 3 . Thanks Armorer

 We would all love to see photos of your finished Boat Howitzer.

[GGaskill]

With a large mould like yours, you need a way to keep the sprue liquid while the ball in the cavity solidifies or you will get shrinkage voids in the middle of the ball.  We covered this subject pretty thoroughly a while back in this thread.  Evil Dog was casting zinc shot but the principles are the same.  Keep the sprue liquid until the casting is solid.

[armorer77]

Thank you . I have read that thread in detail , it would seem that I do not have enough heat . I am a machinist , but barely literate on this computer . I will post photos as soon as I can . I have pics of a similar tube but not of the completed Gun .

[Rickk]

Is your mold steel or aluminum? A steel mold takes quite a while to heat up. Expect to trash a few balls in the beginning. An aluminum one will heat up quicker.

Refractory gloves are a really handy thing to have when using big molds. Look for  "HIGH TEMPERATURE GLOVES" in the cannon supply thread. You can hold onto a super-heated mold for quite some time before things turn bad.

[Max Caliber]

My aluminum golf ball mold has a long 3/8 inch sprue which feed the ball well while cooling and I have no problem with shrinkage. My 2.150 inch, 34 ounce aluminum round ball mold has a cone shaped sprue that is 13/32 inch in diameter where it enters the cavity, I use the large molds just like small caliber molds, I heat them by casting balls and smoke the cavities with a piece of burning wood or kitchen matches if they stick - which the usually don't.  In my experience, small sprues cause pouring and shrinkage problems in large molds.

[Double D]

Don't forget, shooting lead balls much over one inch and you need to drastically reduce your loads.  The mass of lead will raise pressures and cause excessively heavy recoil.  You might want to consider casting zinc for the larger sizes. 

[armorer77]

For those of you who want to know , tonight I cast 3 flawed , but usable balls . I bought a Pyrometer , mold temp. was 540 degrees before a decent cast was made . my sprue was 3/4 x 7/8 with a ,187 dia. feed hole . this needs to be larger . The sprue was molten for 30 secs. but I still had voids . For those with safety concerns , I am casting these balls for proof loads , I will soon be a paid sponsor and will not sell a tube I will not trust my own life with .  Thanks for the input , continue to learn . Armorer











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[armorer77]

For anyone who is interested tonight I cast 8 lead balls , I bought a turkey fryer for the burner , this required modification . I raised the burner 3/4ths of an inch , added a thicker pot rest , the lead pot and mold went onto the plate ,  30 mins. later the lead was molten and the mold was at 600 degrees . The first cast took 3 mins. to harden . The second and following casts took about 30 secs .  The sprue dia. was .312 the res. was 3/4 x 7/8 deep . I have 1 ball that I suspect to have a void . I will be happy to supply the details to anyone who wants them . Armorer

[armorer77]

To anyone who wants to cast big balls , Buy a Pyrometer . My mold settles down at 450 to 465 degrees . I cast 23 good balls tonight . Alloy was wheel weights , mold temp was 460 deg.  , de-mold time about 45 secs.  Armorer

[kevthebassman]

Sounds like you are getting this down to a science. 

[armorer77]

If you are gonna do it , it has to be repeatable . Armorer

[Cat Whisperer]

If you are gonna do it , it has to be repeatable . Armorer

Good point.

One can get consistant results by either measuring the temperature, or building a routine.  Both are a good idea.

[armorer77]

Hi Guys , it's been a while , I am having too much fun shooting my Deck gun with lead balls ! See my ad on the classifieds . The tube is over built and a hoot to see a real projectile going down range .
For those of you with safety concerns . I have 80 acres to play on . I was trained as an Artillery man by the Marines . I maintain a solid mile of buffer behind my impact area , I have the lead casting down , now I will start on the zinc casting . Start with what you know , build on it . Armorer77

[Double D]

One thing to keep  in mind, once you cast zinc in the mould, you will no longer be able cast lead in it.  Don't know why, but I tried it and  all I could get was wrinkled lead balls.

[dan610324]

DD are you sure you had the proper temperatures on mold and lead ??
I dont disbelieve you in your knowledge , but all can make mistakes .
I cant think of any reason why such an thing should happened just because you cast zink balls in it before you used it for lead balls .
if anyone more have the same experiance please let us know .
I have never tried using an ball mold for both lead and zink , but my ingot molds are frequently used for both lead and zink without any obvious defects .
they are never preheaten before casting . the result there doesnt matter , but they are always perfect anyway . how can the result be different in an ball mold ??
anyone ??  ideas ??  guesses ??

[GGaskill]

once you cast zinc in the mould, you will no longer be able cast lead in it.

It's not that you can't cast lead in the mould, it's that the product does not have the smooth surface that it used to have.  Probably something to do with microscopic amounts of zinc remaining on the surface of the mould and altering the degree of wetting that lead sees.  It would be an interesting experiment to wash a zinc contaminated mould in hydrochloric acid to remove any remaining zinc and see if it cast good lead bullets afterward.