Cast lead bullet problems

[dave951]

Mold is too cold and probably the lead as well.

I cast minies and some solid for Civil War guns for competition. Minies are cast at about 850. Flat base solids at about 750. Pure lead both ways.

I preheat the mold with a propane torch before starting. Just play the torch across the mold for a bit to get it really hot, then start casting. Toss the sprue and first couple back into the pot. It should start producing after about 5-10 initial pours.

Use a 20lb bottom pour. Anything less and you run out of lead quick, especially when casting heavy bullets.

 

[Jack Ryan]

When I cast, knock the spru back into the pot, as garandsrus mentioned. its still real hot and helps keep the pot full longer.

Dave

I sure can't hit the top of that pot when I'm knocking the sprues off. A LOT of my casting equipment starts out in a kitchen, for instance I use a cake pan to catch sprues, rejects and any thing else that is going back in the pot and drop my bullets in a bucket of water. The cake pan lets you slide every thing to a corner and pour easily right back in the pot and doesn't splash much either.

 

[Jack Ryan]

I never use a thermometer any more. Every temp you are looking for in casting is right around pretty darn close to the temp lead melts at. Getting it to..., Keeping it at..., A little more, a little less all that beyond getting close is best judged by the results you are getting and those pics are not really very close to every thing you are using being just right.

I set an iron frying pan upside down under the spout to start. It is easy to slide the mold around and get it under there an hold it still even with old man shaky hands. Lets you pour as wide open fast as the spout will pour. I also use a torch to speed the start up from cold lead in the pot and the warm up of the mold. Molds can cool off while you are using them and fluctuate temps, especially if you aren't pouring quickly. I throw a speck of lead on top of that pan and hit the pan with the torch while I'm using it to get the lead started melting. Heat that with the torch until that speck of lead melts. That iron holds a lot of heat/energy and keeps a lot more constant temp than just waving it in the air or laying it on the aluminum base.

I'll hit that mold with the torch a little starting out too, ESPECIALLY THE STEEL SPRU CUTTER. Those first two or three warm up pours I'll fill those spru funnels and even connect them together to get the whole thing up to the correct and all the same temp. Cut those straight in to the cake pan and dump the warm up bullets there to. Repeat until you get good looking bullets. Then dump them all back in the pot, it will all still be really hot. Nothing wasted, heat or lead.

At that point I'll pour about 1/4 of the pot and then lower the temp dial to about 1/2 way or a little hotter to pour the rest of the pot. Watch your lead to know which way to go. If they get looking soft and fat, needs more heat. If they are sharp, it's good. If you are getting flash around the base of the bullet your spru cutter needs tightened a little. If you still get flash it may be a little too hot.

 

[robhof]

All above are good advice, also did you smoke the mold? Candle or even a few matches will deposit a light layer of carbon, also wipe down the entire mold surfaces with alcohol to remove any traces of cutting oil. I've been casting for over 50 yrs and never used a thermometer, good to have but observation is the best, slow to harden after pour is too hot, hardens too fast; too cold.

 

[Jack Ryan]

All above are good advice, also did you smoke the mold? Candle or even a few matches will deposit a light layer of carbon, also wipe down the entire mold surfaces with alcohol to remove any traces of cutting oil. I've been casting for over 50 yrs and never used a thermometer, good to have but observation is the best, slow to harden after pour is too hot, hardens too fast; too cold.

Exactly!

I like to watch that liquid pool on top of the spru cutter the same way I watch the pool following along behind a welding rod. For me it seems it should take as long for the full sprue to harden as it takes to pour the mold full and I open the spout all the way pouring as fast as it will come out of the pot.

On a six cavity mold when I fill the last cavity and pull the mold from under the 5th cavity will be hard or half hard and I will watch the 6th harden and soon as it is, I cut them all. If I pull it out and both the 5th AND 6th are still fully liquid then I'll turn the heat down or drop in few pieces of new lead to cool off the pot.

 

[garandsrus]

When you cut the sprue, hold the mold over the pot and the sprue will fall in. It’s hard to miss the pot if you cut the sprue while it still cuts easily.

 

[Jack Ryan]

When you cut the sprue, hold the mold over the pot and the sprue will fall in. It’s hard to miss the pot if you cut the sprue while it still cuts easily.

What if you cut 6 of them at once?

Oh, and my pot is at eye level.

 

[dave951]

One other thing I haven't seen mentioned yet, put enough on top of the sprue hole to completely cover it. Don't just fill that little chamfer area. What happens as the lead cools, it contracts and not enough lead on the sprue plate can lead to weight variations. Watch the lead cool sometime, that's the little dimple you'll see develop over the sprue hole.

 

[garandsrus]

What if you cut 6 of them at once?

Oh, and my pot is at eye level.

I do it all the time with a Lee mold. Pour one continuous sprue and when you cut the sprue, it generally all goes in the pot. My pot is lower than yours though. Occasionally (2 or 3 times per 30 min or so casting session) the sprue will break and part of it will miss the pot,

 

[Jack Ryan]

I do it all the time with a Lee mold. Pour one continuous sprue and when you cut the sprue, it generally all goes in the pot. My pot is lower than yours though. Occasionally (2 or 3 times per 30 min or so casting session) the sprue will break and part of it will miss the pot,

That would KILL my back to have the pot that low and I got to look through my BOTTOM set of eyes to really see the metal cool in the spru.