I had my first bullet casting session tonight!

[Greg G]

.41 caliber

Lee 210 grain mould

Lee 20 pound furnace

Hardball alloy from Rotometals

http://img641.imageshack.us/img641/3/411stbatch001.jpg


I don't have a lead thermometer yet, so I tried different settings on the Lee melter. It's graduated from 1 to 9. I started off at 7 and with the mould that had been sitting on a hotplate for about 15 minutes.

The first bullets were what I expected from reading here...wrinkled and not filled out. I cast about 20 thinking the hotter the mold got the better it would be. It did help some but it was after I increased the temp of the lead that they started looking good. I ended up running the pot wide open at 9 and the pic above is what I was getting for boolits after everything was shucking and jiving along pretty good.


The good news is that these boolits are measuring 4115" - .412", so they need sizing. I was worried the boolits would drop small from the mould and be too loose for my Model 58 (.411" throats).

Thanks guys!

[tayous1]

They look nice wish I had your problem my first casting find out all of them are casting to small!

But nice looking boolits there hope they load and shoot well for you!

[frankenfab]

Great job. That's one of the cool things about this site, getting to see the brethren grow. So, I assume you are hooked?:grin:

[Greg G]

So, I assume you are hooked?:grin:





I sure am! :mrgreen: :Fire:

[plainsman456]

Those sure look purtty.
Good Job

[onondaga]

How many times a minute are you opening the mold and dropping bullets? If you are dropping 3-4 times a minute that will bring your mold to normal operating temp if your Hardball in the pot is 650 or so. Hardball is a relatively low melt alloy for bullet casting. If you are casting slower than 3-4 drops a minute you won't get the mold up to temperature at all and the full heat of the pot will start another batch of problems.

Check yourself with a watch, the bullets look too shiny like the mold was not hot enough because your casting cadence was too slow to bring the mold to temperature.

Hot plate warming a mold is not a sure thing until you know exactly how long it takes the hot plate to get your mold 100 degrees less than the fluid point of your alloy. Then you have to keep up your cadence casting to keep the mold up to temp. When you get those things worked out in your casting you will find that having your pot turned all the way up will give you severely frosted unusable bullets so turn your pot down .

A thermometer would be a good investment if you are having difficulty judging pot temp. Cool down from full hot to 650 takes a long time and you can be fooled by that too. A watch timing your drop rate will tell you a lot also. You should be able to get 200 drops an hour, that would be 400 bullets from a double cavity mold in one hour. That is a good casting cadence to keep mold temp in the zone for excellent casting. Stopping to check bullets is not a good idea in a casting session. Check them when you are warming the next pot with your sprues and some new ingots to start the next run.

That 200 drops an hour may seem very fast to you if you are a novice, but is very reasonable for a skilled caster with a good cadence that gets good results in general and a reasonable goal to set for yourself.


Gary

[Doby45]

Don't you just LOVE casting? onondaga is right on about your cadence and alloy temps. I was casting Miha 401-165s tonight and they were dropping like rain, hated to even stop. But my molds pre-heat on a hotplate to 400* (use a thermometer) and my alloy was right at 650*, perfect conditions for a Miha 2 cavity mold.

[geargnasher]

Listen to Gary. It seems that ALL new casters want to crank up the heat of the alloy and cast slow with a too-cool mould, I think it must be all the wive's tales and misinformation that still persists which is to blame.

There are four temperatures with which you should be concerned when casting. ALLOY temp, AMBIENT temp, MOULD BLOCK temp, and SPRUE PLATE temp.

First, understand that boolit quality is determined by MOULD AND SPRUE PLATE TEMP, not ALLOY TEMP.

MOULD TEMP is controlled by casting pace, and not alloy temp directly. If the alloy is hotter (more on that next), it will naturally impart more heat to the mould blocks each pour, allowing a slower casting pace for a given mould temp. Casting pace is the key to getting, and keeping, your mould temperature at a point that is making good boolits, and that's for you to sort out with your particular mould, alloy, and weather conditions.

ALLOY TEMP IS DETERMINED BY THE ALLOY COMPOSITION, with a small consideration for mould type and the ambient air temp and humidity. Due to the propeties of tin, if you have any tin at all (1/2% or more) in you alloy, KEEP IT UNDER 750 DEGREES for sure, and you should be able to get right in the sweet spot running it 100 degrees over full liquidus. If it's really cold in your casting area and you're using a brass mould with a lot of mass, you might have to go 125 degrees over liquidus. If you're using a small iron mould that tends to overheat easily and you're casting on a hot day, you might need to go only 75 degrees over liquidus. Regardless, start out setting your alloy (Hardball has 2% tin) temp at 100 over liquidus at first AND MAINTAIN IT THERE. You don't need to monkey with it more than 25 degrees either way to get good boolits, if you aren't getting good boolits, you most likely have a mould temperature issue.

If the mould is too cool, CAST FASTER or preheat the mould on a hotplate, or by carefully submerging a corner in your molten lead until the lead doesn't stick to it any more when you pull it out (usually about 20-30 seconds), then immerse the tip of the sprue plate in the melt the same way, then start casting as fast as you can until you get nice, fully-frosted boolits. You are now a bit too hot, but I want you to go this hot to see what I'm talking about. Hardball, like all antimonial alloys, will frost heavily if the mould is too hot. Now slow down your pace until you get the boolits you prefer. I personally like a nice satin look that leaves a shiny boolit with a twist of a dry rag, a dull surface is too frosty. Many folks like shiny boolits from a slightly cooler mould than I run, but I find the temp window for shiny, yet fully filled-out boolits is much narrower than the light frost window. Suit yourself here, just try to understand the difference between ALLOY TEMP and MOULD TEMP and that the alloy temp you should be running is determined by the composition of the alloy (usually about 100 degrees or so above the point that it's fully melted), and that the ideal mould temp is determined by boolit quality, and mould temp is maintained by adjusting casting pace, NOT the dial on your pot.

SPRUE PLATE TEMP is important, too, and controls base fillout quality. Maintaining or adjusting the temp of the sprue plate is a simple matter of sprue size. If the plate is too hot, and it's still keeping the sprue melted while the boolit is long set, then pour a smaller puddle. If the sprue is rock-hard within three seconds of finishing the pour, yet the boolit is still fragile and grainy when you open the blocks, your plate is too cool, so cover it with hot lead for a few pours, let it run off the sides of the mould until you get it good and hot.

Here's a general rule: Three or four pours a minute is a good casting pace for anything from straight wheel weights to Lyman #2 and anything in between, but the alloy temp will vary some across this range. Straight WW melts in the high 500s, so pot temps should be run at or near 700 unless some tin is added (which lowers the liquidus point), so if you add 1% or more tin 650 is about right most of the time. Lyman #2 can be run cooler. Straight linotype, which melts at 484 IIRC should be run no hotter than 600, often it can be cast at around 550 pot temp, but the casting rhythm's got to speed up to 4-5 pours a minute to keep the mould at a good operating temp most times. With pure lead, you might have to run it at 800 degrees or even hotter to get good fillout, but remember that tin becomes ineffective as a casting aid at temps over 750, so if you're using 30:1 lead/tin alloy with no antimony in it, keep it under 750. It's all a balancing act.

I know this is a lot to take in, but understanding these critical temperature relationships will help you diagnose fillout problems through a long range of alloy types and mould types without the frustrations. There are very specific reasons for not overheating your alloy, especially hardball and other alloys containing a significant amount of tin, but that's a long story in itself. Just trust me on it for now!

Hope this helps,

Gear

[Greg G]

First, thank you for the time to review my work.

I was working slowly. Just trying to "Take in" everything.

I have two NOE moulds on order. I will have a lead thermometer placed with one order.
I'm going to read and read and read this thread until everything in it is in my head. I'll come out of the gate next a different caster with any luck.

Thanks for the post and advise.


greg



How many times a minute are you opening the mold and dropping bullets? If you are dropping 3-4 times a minute that will bring your mold to normal operating temp if your Hardball in the pot is 650 or so. Hardball is a relatively low melt alloy for bullet casting. If you are casting slower than 3-4 drops a minute you won't get the mold up to temperature at all and the full heat of the pot will start another batch of problems.

Check yourself with a watch, the bullets look too shiny like the mold was not hot enough because your casting cadence was too slow to bring the mold to temperature.

Hot plate warming a mold is not a sure thing until you know exactly how long it takes the hot plate to get your mold 100 degrees less than the fluid point of your alloy. Then you have to keep up your cadence casting to keep the mold up to temp. When you get those things worked out in your casting you will find that having your pot turned all the way up will give you severely frosted unusable bullets so turn your pot down .

A thermometer would be a good investment if you are having difficulty judging pot temp. Cool down from full hot to 650 takes a long time and you can be fooled by that too. A watch timing your drop rate will tell you a lot also. You should be able to get 200 drops an hour, that would be 400 bullets from a double cavity mold in one hour. That is a good casting cadence to keep mold temp in the zone for excellent casting. Stopping to check bullets is not a good idea in a casting session. Check them when you are warming the next pot with your sprues and some new ingots to start the next run.

That 200 drops an hour may seem very fast to you if you are a novice, but is very reasonable for a skilled caster with a good cadence that gets good results in general and a reasonable goal to set for yourself.


Gary

[Greg G]

Thanks geargnasher for the post. I will read it until I understand it. I promise you that.

Thanks for helping me.

[Southern Son]

Greg, everything you need to know about casting is on this website. I can't believe that nobody else has told you the rules of the forum, though. You showed us a photo of the boolits, and that is good, but you can't talk about a gun and not put up a photo of it. :kidding:

[geargnasher]

If you have a couple of NOE moulds on the way, go ahead and invest in a $12 hot plate, it will save you a lot of aggravation getting those large aluminum mould blocks up to temperature. Also, follow the instructions Al sends with them, using the Bullplate sprue lube very sparingly, and don't even try to get keeper boolits until you've run at lease three warmup cycles. He doensn't include the note with his moulds because he likes killing trees! Doing this will save you from second-guessing your casting skills with a "green" aluminum mould. Also be sure and order a set or two of the Lee six-cavity commercial mould handles from your favorite reloading warehouse.

I also got a thermometer from him, I have several but it was time for an extra, and I found it within two degrees of spot-on at 621 degrees. Can't beat the deal he has on them, either.

When you get your thermometer, here's a foolproof routine you might try with broken-in moulds: First, turn the hotplate up to a medium setting, place a small piece of steel or aluminum on it to distribute heat, place the mould on it sprueplate-side-down, and turn your attention to the pot. Turn it on, add alloy (if not alread in there), and wait until it starts to melt. Shove your thermometer probe into the alloy as soon as you can to get the solidus temperature. There will be a long "slush" or "mush" stage to Hardball and similar alloys, so stay with it and observe the temperature reading on the thermometer (with at least 3/4 of the probe submerged), it should be fairly level during the mush stage as the alloy completes it's phase change. Stir it around with a stainless steel teaspoon while observing the temp. When the temp starts to climb, it should coincide with the disappearance of any and all solid particles of unmelted metal in the alloy. Stir with the spoon to verify it's all melted, and observe the temp where you think it was fully liquid. Let the alloy get 75 degrees hotter and cut the switch. The temp should climb some more due to residual heat in the element, but try to adjust your pot setting to maintain the 100-over-full-liquidus temp. At this point you can flux the dross and oxides, and skim the remaining crud off the alloy. Your mould should be hot by now, so get to casting! The sprues should take 3-6 seconds to set just firm enough where you can open the sprue plate with just a gloved thumb, no hitting it with a mallet. Adjust your casting pace until the temperature of the mould is up to it's happy place and start casting keepers. You should have fewer than ten pours to achieve bliss using this method. Keep an eye on the pot temp, it can swing wildly as the lead level goes down. Adjust the dial as necessary to keep your alloy at it's pre-determined ideal temperature.

Gear

[harvester]

My Lee 20 pound pot runs at 700 degrees on setting 4 if pot is full. When pot gets down a little I have to turn it down to 3 to stay between 650 and 700. when I first got it I noticed it would go to 900 on high quite easily and I never tried to see how hot it would go. Lyman thermometer. Good boolits come out at 650. Yesterday was a good day for all but 452 Lee flat nose but that was due to dirty mold.....So I say get a thermometer...

[gray wolf]

I have followed Gear's advise to the letter and I am very happy with my results.
But I did not stop there, I tied a lot of other things in an effort to prove him wrong.
Also to see why he was correct, needed to see for myself. But I also new I had his info in my pocket so to speak. My 20# lee will off the scale on #9, I am able to maintain 650* 675*
with a setting of about #3 on the pot. I cast for years without a thermometer but now that I have one I can see how much I didn't know about maintaining pot temp.
If I cast WW alloy with a little tin at 800* I would get about one fill a Min.
That's Gears story and I'm sticking to it.

[exile]

I have been hanging around here a long time without actually casting (finally started the other day, no good booits yet to speak of) and I would say this is some of the most helpful information I have seen yet.

I bought the Lee 195 grain .41 mold for myself as a birthday present, hope I can eventually get nice looking boolits like that myself.

exile

[Dennis Eugene]

This is a very good post! Wish I would have had one just like it to read back when I started. Great job Gary and Gear. Dennis

[geargnasher]

Me too, Dennis, it's taken nearly 20 years to learn all this, when what I know can be condensed to it's essence, learned, and understood with a couple of evening's worth of reading and a few casting sessions. I had a good mentor when I started learning about cast boolits, but he was a "Zen" caster, and one must find Zen on their own.

GW, I did it every wrong way I think there is before I found what worked best for me. Once I finally understood the chemistry and the physics of casting, it dawned on me that there's really only one way to do it right, meaning to get the most consistent end product. I wish the boolits from my first, or even 10th casting session looked as good as Greg G's first ones, but I figured it out eventually with a stack of books and a lot of help from Castboolits.

Gear