Casting Issue

[dave951]

Turn the heat up and pour faster. I cast .69 round ball at 800 and pour fast. I have an RCBS mold and mine is steel.

 

[Walkaheap]

Along with what the others have said, if for any reason you have to pause, to add lead, clean a splatter, or scratch your nose, leave a cast ball in the mold to help retain heat in the cavity.

 

[johnfrommd]

I cast with six and eight cavity molds and always work two molds at a time. After I fill the mold, I lay it on a hotplate that is adjusted for 350 degrees. This keeps the mold from cooling too fast. I start with the melt temp at about 800 and turn it down as the balls fill out to about 750. I have a small 10 pound melting pot waiting for when my 20 pounder gets down to 1/2 full. After it gets down to 1/2 full the second time, my arms tell me I am done for the day.

 

[andy52]

Place the mold on top of the furnace when you start heating the lead. If you don't have a way of testing the lead for temperature heat it until the surface starts to turn blue and back it off just a bit.

 

[johnfrommd]

I suggest that a required tool when casting is a lead thermometer. Not the electronic type but the type with a dial and stem. Knowing the exact temperature of your melt makes for better casting and less wasted energy.
The reason I don't recommend the electronic type is that, for some reason, they won't read correctly when aiming at molten lead.

 

[mooman76]

They don't read correct because of reflection. You can float a small piece of dark steel on top of the lead to get a more accurate temp.

 

[CapPopper]

As bad as that looks the mold is definitely too cold if it's not got oil in it. Even somewhat cool lead comes out of a hot mold looking better than that. Leaving the mold in the melt until lead doesn't stick to it is good. I will also set the mold In the melt if I need to do anything else . Frosted balls will not hurt anything and is something I desire in my bullets for modern guns so I know they are fully filled out. I have more issues with little balls personally cause there isn't enough lead going into my .311 mold to keep it hot even running both cavities but I can get good balls put of my .562 mold with one cavity. Run your lead hot and odds are you can't ladle cast fast enough to overheat the mold. If the mold is not flashing it's not too hot yet. Blue on the surface is a good indicator but it's not something that is as noticable in an alloy.

 

[JCKelly]

Mold too cold
Don't waste $$$ getting a thermometer.
Your mold is too cold, that's the whole thing.
Lots of suggestions here how to get it hotter.
Whatever the dxxx thermometer says, you will know the mold is hot enough when balls come out smooth & shiny.
Dad taught me how to handle molten lead, decades before it was such a deadly poison.

 

[SPQR70AD]

I would suggest two things:

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

what is easier is to stick a corner of the mold in the melted lead pot to heat it up

 

[Griz44Mag]

A hot plate is the ticket to keeping a mold hot enough.
When I fire up to start casting, the lead pot(s) get plugged in and the hotplate gets turned on - the molds go on the hot plate so by the time the lead is ready the molds are ready.
If you stop for a break or other stuff - put the mold back on the hot plate, wrinkles are a cold mold - get them hot and keep them hot.

 

[brewer12345]

what is easier is to stick a corner of the mold in the melted lead pot to heat it up

I find a hotplate is less messy, more consistent, doesn't risk warping the mold, and best of all: if I want to cast two molds in a session I can put mold#2 on it while working with mold #1 and the second one is ready to go whenever I like.

 

[cynthialee]

the nice thing about using the melted lead is it gets the mold the same temp as the lead in the pot so there is no sudden severe temp change for the lead

that hot plate is going to be a few hundred cooler than the lead

 

[brewer12345]

the nice thing about using the melted lead is it gets the mold the same temp as the lead in the pot so there is no sudden severe temp change for the lead

that hot plate is going to be a few hundred cooler than the lead

I'd guess both methods work well.

The other thing worth mentioning is that steel molds hold their temp better than aluminum. I cast with both, but I can tell you that the old Lyman 4 cavity molds get up to temp and stay there. They are heavy, but once you are in the zone you can just cast and cast. I picked up a .375 ball Lyman 4 banger and am eager to get it going soon to feed the 36 cal revolver.

 

[Des52]

The mold in the top of the pot may work for one mold at a time, but I use up to four molds at a time and a hot plate is the way to go. I can keep all the molds hot at the same time, have a two burner and keep two molds on a burner.

 

[jdw276]

Not trying to steal this thread. Have cast a lot of roundball. Lee molds, lee bottom pour. I have a hard time getting my lee .311, 2 cavity roundball mold to fill out. I get a line usually halfway just like the op pics. I know the lead is hot as when i do 375, 390, 440, 490 etc at the same time, no lines with those. So it must be the mold is not hot enough. Mold is clean and nothing inside the mold. But those littles things just do not have enough heat to transfer to the mold and get the mold hot and keep it hot. Only thing i can come up with.

 

[Griz44Mag]

Not trying to steal this thread. Have cast a lot of roundball. Lee molds, lee bottom pour. I have a hard time getting my lee .311, 2 cavity roundball mold to fill out. I get a line usually halfway just like the op pics. I know the lead is hot as when i do 375, 390, 440, 490 etc at the same time, no lines with those. So it must be the mold is not hot enough. Mold is clean and nothing inside the mold. But those littles things just do not have enough heat to transfer to the mold and get the mold hot and keep it hot. Only thing i can come up with.

Get your mold hot enough in the first place, and then control the mold temp with your casting pace.
If you can't get your .311 mold to stay hot, then cast faster.
Small molds need a fast casting pace, larger or steel molds require a slower pace,
For my large 6 cavity molds I have a 6" long piece of square tubing I use to suck heat out of the mold because they will get too hot with a fast casting pace.
With the 6 cavity molds I can cast 3 times a minute until they get too hot, then I need to start wicking off some of the heat with the square tubing heat sink.
It's all about mold temperature, casting pace and filling a mold quickly. A mold that is too cold will not make good casts.

 

[James Dietz]

I clean my mold before use with a match. Just let the flame burn in the cavity for a bit. Then I heat the mold over the pot as the metal heats. (Insulated handles are important here) I do not use a drop pour pot but ladel the metal in. I say metal because while I try to use as pure a lead as I can there can be impurities. So, I "flux" the pot every time I add more metal. Fluxing is when you take a small amount, size of a pea, of pure bee's wax and drop it in the pot. It can be dramatic. Lots of smoke and sometimes a flame if you use too much. What happens though is all the impurities float to the top and can be skimmed off leaving you an almost mirror finish to the metal. Here is my background, only casting ball for four years but the previous 20 years and to now casting toy soldiers where detail is paramount. Once heat and purity of metal are accomplished, cast as quickly as you can. I will back up Cynthia Lees words on not being slack and being very safe. A bad accident can occur with just a moment of complacency. Having said this, with both ball and toy soldiers the first few castings are usually not perfect. Also, in my experience, the larger the ball the tougher the casting.

 

[johnfrommd]

Not trying to steal this thread. Have cast a lot of roundball. Lee molds, lee bottom pour. I have a hard time getting my lee .311, 2 cavity roundball mold to fill out. I get a line usually halfway just like the op pics. I know the lead is hot as when i do 375, 390, 440, 490 etc at the same time, no lines with those. So it must be the mold is not hot enough. Mold is clean and nothing inside the mold. But those littles things just do not have enough heat to transfer to the mold and get the mold hot and keep it hot. Only thing i can come up with.

Try running a scribe along the vent lines. It seems to me, the air is not getting out of your mold causing the lead to not flow properly.

 

[johnfrommd]

If you use beeswax for a flux, keep some match heads on your bench and throw one in with the beeswax. This will ignite and keep the beeswax from smoking.

 

[oldwood]

The balls I see show dirt in the grooves. Dirt in the casting defects , shows maybe an unfluxed pot, and or scooping a casting ladle of hot lead from a dirty uncleaned surface layer in the pot. The dirt and impurities float on the surface of the melted lead go right into the mold and looks just like the photo. To help w/ this problem , keep your surface lead clean by skimming the pot surface w/ an old spoon. The other way to avoid the impurities in balls , is to use one of those Lyman Lead Dippers. Fool proof , but a little pricey $28.50.. Been using one of the Lyman dippers for 50+ yrs , as well as Lee Production Pots and the rest of Lee's pots. All excellent , and reasonably priced. More fun than I deserve......oldwood