First cast

[jkcerda]

Lee bottom pour 4-20.
Lyman 462460 -4 cav mould

i am getting a few Boolits with what I can only describe as a "swirl" look. Pot is brand new and the mould I bought used.
I'll post up pics tomorrow , see if I can
Capture the swirl on some, any ideas as to why some look this way?

[waco]

Make sure the mold is clean. Free from ANY oil, dirt, grease, etc......
Sounds like you need to get the mold hotter. Try pre heating the mold on a hot plate. This is what I do. Also, cast fast. Don't stop to inspect or look at your boolits. Keep a good cadence. This will keep the mold hot.

[Yodogsandman]

Cold mold or oil residue in your cavities. You can just continue "practicing" and it'll all work out. Cast as fast as you can, without looking too close, until the boolits appear frosted. Then you can slow down your cadence a bit. This will heat up the mold to the proper operating temperature. When you slow down you'll notice that the boolits will start to drop out nice and shiney. Sometimes you have to do this cycle a few times with a mold for the oils to work out of it.

[jkcerda]

Mold was cold, all the bullets are shiny

[bangerjim]

Always..........PRE-HEAT the mold to casting temp on an electric hot plate! And......not just warm.

Be sure you are pouring right down the center of the sprue hole, not allowing any swirling around in/on the sprue plate.

If your mold is at casting temp and your alloy is at recommended alloy casting temp, you will get good boolits. Grease & oil will not cause your problems. You can clean it until your fingers are raw and the mold cavities are totally void of grooves! If it is NOT at temp, your boolits WILL be wrinkly, swirrly, whatever you call it.

Heat it up and give it another try.

bangerjim

[jkcerda]

Dang it. Won a second mould just like this one on e-flay
is there a point where they get too hot? Shoukd I try alternating between the 2? Or just do one per session and keep it hot?

[MT Chambers]

I usually work with 2 Lyman 4 cavity molds at the same time because they stay hot, however in your case start with one and get it up to operating temp first. That's an excellent mold and great design.

[Foto Joe]

Your 4-hole Lyman mold will take quite a bit of time to get warmed up because it's iron and BIG. You can set your mold on top of your pot (don't let it touch the molten alloy) while the pot is warming up, this won't get it up to operating temperature but it will help immensely. I'm not a fan of the hot plate trick but that's just personal preference, there's a lot of folks that use 'em with great results.

Although it's harder to do with an iron mold you do want to avoid getting the mold too hot during casting. Make sure that you let that sprue harden adequately, especially as the mold heats up after 15-20 pours. If you break the sprue too early you'll wind up getting lead smearing on the bottom of the sprue plate which is a bugger to clean off. It can also easily damage an aluminum mold which easily over heats when casting along at a good clip.

For now until you get your feet wet a bit I'd recommend just running one mold at a time, if you were in a hurry to get boolits you'd go buy 'em right?? Once you've gotten really comfy with the process then go ahead and run two or three at a time. Once you do you'll find that it's a good way to keep from over heating large six cavity aluminums but it'll also demonstrate just how fast you can empty a 20 pound pot too.

Have fun and don't get caught stealing the weights off the neighbors cars.

[jkcerda]

Your 4-hole Lyman mold will take quite a bit of time to get warmed up because it's iron and BIG. You can set your mold on top of your pot (don't let it touch the molten alloy) while the pot is warming up, this won't get it up to operating temperature but it will help immensely. I'm not a fan of the hot plate trick but that's just personal preference, there's a lot of folks that use 'em with great results.

Although it's harder to do with an iron mold you do want to avoid getting the mold too hot during casting. Make sure that you let that sprue harden adequately, especially as the mold heats up after 15-20 pours. If you break the sprue too early you'll wind up getting lead smearing on the bottom of the sprue plate which is a bugger to clean off. It can also easily damage an aluminum mold which easily over heats when casting along at a good clip.

For now until you get your feet wet a bit I'd recommend just running one mold at a time, if you were in a hurry to get boolits you'd go buy 'em right?? Once you've gotten really comfy with the process then go ahead and run two or three at a time. Once you do you'll find that it's a good way to keep from over heating large six cavity aluminums but it'll also demonstrate just how fast you can empty a 20 pound pot too.

Have fun and don't get caught stealing the weights off the neighbors cars.

[jkcerda]

Sprue is easier to handle/break once it gets hot, Boolits look GREAT .

[500MAG]

I alternate moulds and keep an inch thick aluminum plate next to my pot to lay the one mould on while a pour the next. The aluminum quickly pulls heat away from the hot mould. Once you get the rhythm going it's great. It's a bummer when the pot runs dry.

[jkcerda]

I alternate moulds and keep an inch thick aluminum plate next to my pot to lay the one mould on while a pour the next. The aluminum quickly pulls heat away from the hot mould. Once you get the rhythm going it's great. It's a bummer when the pot runs dry.

I might modify one of the moulds to be HP. thinking about it. Price is a tad steep at the moment

[shoot-n-lead]

It's a bummer when the pot runs dry.

That certainly is a buzz kill...

[Foto Joe]

Sprue is easier to handle/break once it gets hot,

This is true but there's a happy medium. Keep an eye on the underside of the sprue plate, if you start getting a "silver stripe" leading from the sprue hole itself to the edge of the plate it's time to slow down a bit. On my two hole molds I use my hand to break the sprue once things have warmed up, it gives me an idea as to how hot the mold is getting and when it gets too easy to break the sprue it's an indication that I need to slow myself down a bit. I've probably fouled every one of my molds with a lead smear at one time or another and it can be a chore to clean up. The problem on the aluminum molds is that the smear can gall the top of the mold blocks.

[Sticky]

Heating your mold on top of the pot as it's warming up works pretty well if you don't have a hot plate handy.. for aluminum molds, I set my molds sprue plate down against the rim of the pot, as the sprue plate doesn't heat as quickly and easily as the aluminum. By the time the pot is molten and ready to cast, the mold it warmed sufficiently. I can do two molds like this if I'm careful, but I now use a hot plate.. easier.. lol

[jkcerda]

Used an aluminum plate on the range to warm up the mould