poor casting

[kudu]

I just got a new Lee .395 round ball mould and im not too happy with it. It's a double cavity and im using a Lee electric pot with pure lead. and Marvelux. 

The balls are not very round and have a parting line  where the halves meet (not a sprue) and the two cavities are not even the same diameter.

I have a older Lee .390 single cavity and it cast a real nice ball their round and have a nice finnish. the quality is alot better.
 
I can tell you I been a machinist for 25 year's and the quality is just not too good- the fit between the halves is poor and  the finnish is also sub par.

Im not a black powder expert , really a green horn but in my limited experience I belive that aluminum is a poor choice of material for casting. it has a very high elongation/ expantion rate.

I think Cast Iron If I remember my materials class from my apprenticeship is very  thermaly stable, the good stuff with fine grain and a lower carbon content similar to Ductile Iron.  just dont drop it in cold water when hot

Anyone one this site ever make a round ball mould themselves?
 
Thats the Smoke Im blowing today!!
 

[Daryl]

Send the wonky mould back.  When using my Lee moulds, I find I have to lube the alignment bars with a tough of beeswax, now and them, or the alignment of the mold blocks suffers.
If you are not having trouble with a different set of Lee blocks and only with the new set - I'd send them back to Lee.
I personally prefer Lyman, RCBS or the old Ohaus blocks. Tanner moulds also cast well for me, but - I spray all my blocks, Lee, Lyman, etc, etc with Ms. Moly bullet spray.

[bob in the woods]

My set up looks much the same, except I use a Coleman stove and a cast iron pot. I have an old Green Mountain .540 mould, and it is aluminium, but the old is anodized. Seems to work well.  I do prefer my Lyman and RCBS moulds though. They seem to suit my rhythm better, without getting too hot.

[wmrike]

I just got another Lee mold and it's great.  If yours is really throwing bad balls, it probably slipped through inspection.  Send it back.

Much like Daryl suggested, something to coax the blocks into alignment is a good idea.  I apply some anti-seize to the critical parts of the mold before each session and it really helps.

[Daryl]

Too- with my Lee blocks, I use my gloved hand to align the block halves- or by tapping on the bottoms with the hammer handle.  Now, I mostly use a gloved had, for springing the sprue cutter and for alignment when closing. I wear the heavy lined work gloves, leather palm, denim backs.  For years, I used the hammer handle for opening the block halves, but not any more. If a ball or bullet sticks in the mould, I have th hammer handle for tapping the hinge, but with the moly spray coating, the balls and bullets rarely stick now. those are .574" x .574" from a Lyman .570" mould, in the top picture. They SHOULD look like jewels, and all perfect.

[ScottH]

Kudu
 LEE has an unconditional guarantee. I'd return the mold either to the place you bought it or directly to LEE. They should make it right with you.
Most seem to prefer Steel for molds but they are about twice the cost to buy over LEE's aluminum molds.

[JPK]

I've made a couple of molds with aluminum and find it to be good. This is for a 1 3/4" cannon cast of pure lead. These are round to .005 except at the sprue and that is trimmed with side cutters the lightly hammered to blend. As the others say, send it back and Lee will make it right.

[Hungry Horse]

Oh my, I find myself in agreement with Daryl, oh, well he is 100% right about Lee molds. I have had dozens of them, new, and used, and they all threw a good ball. I have had issues with the Sprue cutters on some of the heavily used ones, but they still made a good ball.

  Hungry Horse

[hammer]

If new to casting then it could be the mold halves are unevenly heated or overheated.  That can warp the mold and give the result you have.    Important the mold is preheated with the two halves clamped together.  And, often overlooked, the sprue plate also preheated.   Partly formed balls/bullets can be down to an under heated sprue plate rather than too cool a mold body.  More heat to the body can just overheat it.
If not the above then, of course, send back.
Good luck.

[Scota4570]

Those molds need to be lubed. They tend to gall under the sprue plate and on the alignment wedges.  Moly bore paste works good for this.  Don't contaminate the cavity with the grease.  Clean the cavities then smoke them.  A propane of map gas torch with the air choked off works well for this.  It makes a huge difference.  Finally throw the Marvelux away.  It will rot your melting pot over time.  A dab of wax works great for fluxing.  Use a pinch of smokeless powder to ignite the smoke. 

[Daryl]

LOL- just counted - 22 Lee Aluminum moulds, 38 Lyman, RCBS and Ohause & Saeco, all iron blocks, and 5 Tanner brass moulds.