Casting Issue

[winter1857]

I've recently started casting balls for my black powder guns and I've run into something that I'm trying to remedy. When casting .690 round balls I get these very noticeable striations on the surface. This doesn't occur when casting .445 or .375 round balls.

In all cases I'm using RCBS aluminum molds and lead from a 60 pound batch that was given to me by an acquaintance. (It's intended use was fishing weights.)

Other than the mold size all things are equal but most of the .690 balls have these striations. My thoughts are that I need to slow down and make sure that the mold is properly heated up again between each new pour.

I've not had the opportunity to cast since before the holidays but I'll be experimenting soon. Any suggestions would be appreciated.

 

[Phil Coffins]

Mold and/or lead not hot enough. Did you clean ALL the oil off the mold before starting? Also a faster pour may help.

 

[winter1857]

Mold and/or lead not hot enough. Did you clean ALL the oil off the mold before starting? Also a faster pour may help.

I clean the molds with brake cleaner so I don't think that's the problem.

I'm using a small Lee casting furnace and I'm using the same temperature setting regardless of what size ball I'm pouring. Would large balls like .690 need to poured at a higher temp that smaller ones? Or do I just need a higher temperature in general?

 

[Whitworth]

Crank the heat up, that's a lot of lead stay hot in the mold.

 

[Whughett]

The lead should be around 700 degrees. Aluminum molds heat quickly but cool quickly.
I watch the sprue the second it “frosts” I strike the sprue plate open.
My biggest however is a .562 roundball and 255 grain 45.

 

[hawkeye2]

Brake cleaner will do to clean the mold. You probably don't want to slow down but rather pick up the pace. You shouldn't have to worry if the mold is hot enough between pours if you are casting fast enough. The only concern should be if the mold gets too hot. Try turning the temp up too as others have said.

If you are using a ladle try to increase the speed that you pour into the mold with. You may want to open up the hole in the sprue plate with a countersink. I had to do that with my .735" Lyman mold. The "one size fits all" doesn't work.

 

[Whughett]

Brake cleaner will do to clean the mold. You probably don't want to slow down but rather pick up the pace. You shouldn't have to worry if the mold is hot enough between pours if you are casting fast enough. The only concern should be if the mold gets too hot. Try turning the temp up too as others have said.

If you are using a ladle try to increase the speed that you pour into the mold with. You may want to open up the hole in the sprue plate with a countersink. I had to do that with my .735" Lyman mold. The "one size fits all" doesn't work.

And use a full ladle, the lead needs a bit of back weight as it fills the mold. I use a ladle by choice and leave a fairly large sprue.

 

[Phil Coffins]

I have trouble with bigger ball as well, running ball as fast as I can helps. Turn up the heat till you get frosted ball then back down a little. These 1 3/4” ball weight 1.06 pounds each and I’ve yet to get perfect one.
IMG_1087 by Oliver Sudden, on Flickr

 

[bisleyjohn]

I cast .620 ball. Your marks indicate that the mold is too cold. Keep the mold on the furnace while heating up and between pours. I have also drilled out the pour hole by one drill size (I can't remember the size, it was years ago, sorry). HTH?

 

[Whughett]

I have trouble with bigger ball as well, running ball as fast as I can helps. Turn up the heat till you get frosted ball then back down a little. These 1 3/4” ball weight 1.06 pounds each and I’ve yet to get perfect one.
IMG_1087 by Oliver Sudden, on Flickr

Holy Moly Joe, what you shoot with them things.?

 

[hawkeye2]

I forgot to mention I drilled out the hole in my vintage Lyman ladle to pour faster.

 

[stikshooter]

I've recently started casting balls for my black powder guns and I've run into something that I'm trying to remedy. When casting .690 round balls I get these very noticeable striations on the surface. This doesn't occur when casting .445 or .375 round balls.

In all cases I'm using RCBS aluminum molds and lead from a 60 pound batch that was given to me by an acquaintance. (It's intended use was fishing weights.)

Other than the mold size all things are equal but most of the .690 balls have these striations. My thoughts are that I need to slow down and make sure that the mold is properly heated up again between each new pour.

I've not had the opportunity to cast since before the holidays but I'll be experimenting soon. Any suggestions would be appreciated.

View attachment 112062

Pure lead requires HOT/HOT ,crank it up and wrinkles go away /Ed

 

[winter1857]

Thanks. everyone, Great advice!

 

[bubba.50]

Using Lee equipment I turn the pot all the way up and pour as fast as I can open & close the mould.

 

[Stony Broke]

Does appear that the lead is cooling too fast in the mold....so either the mold isn't hot enough or the lead is going into the mold too slow and cooling on the way. I think if you were to turn up the heat, it might solve your problem. If you get them too hot, they will appear to frost....and if they get to that point, just back down the heat a little.

 

[brewer12345]

I would suggest two things:

- get the lead in the pot up to 800F
- preheat your mold on a $10 hot plate.

 

[bang]

Hotter mold and lead. Don't know what you melt in but open the spout more for faster pour. My Lee 10lb bottom pour is opened to .040 for up to 58 mini. Works great.

 

[Steve Martin]

As others here have said those marks indicate the lead is too cool. I use a Lee bottom pour pot and my average pour is about 750 degrees or between the number 5 and number 6 on the temperature control dial. The balls will be very "frosted" if you get the lead too hot, then back off the temp. control some. I keep my aluminum Lee molds on a hot plate next to my pot so they stay at an even temp. It's also important to "smoke" the insides of your molds using a match, or Bic "long nose" fireplace style lighter. The black coating may not seem important but it sure is - it allows the mold to release the lead balls quickly and evenly.

 

[Master Blaster]

Less than $25 from Amazon.

 

[cynthialee]

I hand cast my own. Learned how from the guys here. There were 3 or 4 forum posts I made while I was learning how to do it. There is an obvious progression in my knowledge and skills through those posts.

I heat up my mold by putting the corner of the mold into the hot lead once it liquefies. A few minutes later the mold will be up to temp.

if the lead sticks to the mold it is still too cold
if the lead rolls off the mold when you take it out then it is good to go

once you get casting, you want to cast as fast as you can do it while maintaining your concentration, and safe practices
now you don't want to rush, but you don't want your mold cooling off, get a steady rhythm going and maintain rhythm

pot lead level is important to maintain

Molten lead is not something to get slack or complacent around. It will screw your world hard if you fail to respect it. Wear safety gear. Cast in a safe place. If you are going to do it outside, you make sure there is no rain on the horizon. No conversations or distractions. Keep focused.