Difficult mold....

Been struggling with a new aluminium 4 cav 350 gr. Mold. I scrubbed out the cavities with hot, soapy water, I heat cycled it 3 times and it would just not settle and pour without those thin voids up one side or another. Good alloy that works fine in other molds. So i Lee mented it ( polished the cavities) and debured the edges with a pencil eraser. Even with all that i must really pre heat it hot and cast frosty boolits to get it to drop without voids. Maybe it will settle in over time? I'm thinking maybe the depth and spacing of the lube grooves is causing freak turbulence with the molten lead as i pour, just a geometric quirk.....

Did you smoke it lightly with a sooty flame?

Failed to read the negative impacts on the bullets ….

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Originally Posted by HWooldridge

Did you smoke it lightly with a sooty flame?

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It drops them o.k. but it would be better not to have to run the mold so hot.

I have had a few do that steel and aluminum. After a few years of not using them I sat one on a heat plate one day when I was casting and after 3 or 4 hours I picked it up and it worked. I didn't have anything to loose so I did the other the same way and it worked also. Smoking with a candle helps a little also. I would like to know your fix. Brake cleaner or carburetor spray is all I use if anything after casting and that's after they cool down.

Have you tried using a dipper to fill the cavities. I ran into that with bottom pouring a 240 gr 8mm, finally use a dipper and got perfect boolits. I have a couple of 310 45 cals that do the same thing with a bottom pour. Just a thought.

I have had several new mold that would not cast a unwrinkled bullet in the first 3 to 4 sessions then magically about the 4 to 5th session problems disappeared.
Since I have started to refine my break in period.
new mold gets cleaned and scrubbed with dish soap and comet
oiled and heat cycled 3 times.
Then a light casting session of 50 or so bullets no regard to how they come out. let the mold completely cool
repeat 2 more times cleaning and casting 50 or so unless I begin to see that its producing good bullets.
Done this with about 4 previously difficult to cast molds and ALL have come around and cast fine now

I should get one of those Lyman lead dipper ladles ( while they are still making them) and try that. I've cleaned the mold quite a few times and i'm fairly certain dirty cavities are not the issue. Hearing that others have had the same problem provides some solace.
Here is the little bugger.....

Attachment 294811

Try a Ladle and pressure cast with it ... This is how I get my absolutely Best , 100% perfectly filled out boolits ... and if the little void keeps showing up ... the Mould might be Possessed by an Evil Spirit!
Gary

If I get voids on the sides of the bullets being cast, I will try pressure filling from a bottom pour pot. Perhaps the cavity is still barely off gassing and pressing the alloy fully against the mold surface will correct the issue. I like lightly frosted bullets because that usually indicates a well filled and consistent bullet weight.

Well i did kind of figure it was my pouring method that was doing it. What i don't care for with frosty boolits is the loss of sharp edges on the grease grooves. Going to heat up the pot again and give that a try Dusty.....

Flood each cavity as fast as you can. Don't let the lead swirl around the sprue plate and down the hole, or tilt the mold while filling. Just concentrate on getting as much of that hot lead through that hole as fast as you can get it in there, and leave a generous sprue puddle, at least until the sprue plate is nice and hot. Cast fast until you get nice boolits and you can slow down to admire or cull when it starts frosting. But cast like your arm was on fire until you get good drops. Good luck!

Okay, I held the sprue plate right against the pour nozzle and this was the result!

Attachment 294832

Man, this was making me crabby. Thanks Dusty!!!