Am I doing this wrong ???

[Willee]

I am using a new LEE lead pot and a new LEE 6 cavity mold.

If I stick the pot spout into the mold sprue cutter it will fill the mold completely making a nice flat base bullet flush with the mold.

If I hold the mold about 1/4" below the spout and flow the lead in that way ... the mold seems to fill all the way but it leaves the bottom edges of the bullet a bit rounded ... to the edge of the mold.

I have smoked the mold ... got it hot ... and run the lead pot all the way up.

Is this normal?

Willee

[popper]

You didn't state the CB (FB or BB?) and mould. If you cram the spout into the sprue cutter, you push it against the mould base. Dripping doesn't do that.

[ku4hx]

Your sprue plate may be a bit too loose. When you place the plate in contact with the spout, you push the plate down onto the mold closing the gap between the two surfaces.

[geargnasher]

Sprue plate is too cold, the metal is "shying away" from the sharp corner wher the sprue plate covers the base. Cast faster and pour a large sprue on top of the plate, linking all six holes into one big, heavy sprue that will put heat into the sprue plate. When the plate is hot enough that you have to wait six seconds before cutting the sprue to prevent smearing molten metal on top of the blocks, then you can start pouring smaller, pinto-bean-sized sprue puddles to maintain heat.

Gear

[Willee]

Here is a photo ...
The two bullets in the center were dribbled in with the spout about 1/4" above the sprue hole.
The others were with the spout pressed into the sprue hole.

Willee

[docone31]

Your mold is too cool.

[Echo]

When you press the spout against the sprue plate, you are Pressure Casting. You have a head of lead, to the top of the melt, and that forces the alloy into all areas of the mold. When you dribble, surface tension of the alloy makes corners rounded, which leads me to believe that you don't have enough Sn in your alloy. Sn's main virtue is that it lowers the surface tension, allowing complete mold fillout. It does other good things, too.
So what alloy are you using?

[sqlbullet]

I am with Gear and Doc. Your mold is cold. When you press the spout into the sprue plate you are transferring some heat that helps with fill out at the top. Run four-five pours as fast as you can an without smears, all with one big sprue for the whole mold. Then run a test pour. I would bet your issue goes away.

One other thought, which is less likely but possible. I get poor quality bases if my lead flow is too fast The mold can't vent. Pressing the spigot into the sprue would give some pressure which may fix this. I find the ideal speed has to be tweaked depending on the boolit size and shape.

[IllinoisCoyoteHunter]

Yup, these guys nailed it. Be sure to pour a generous sprue to get that sprue plate up to temp. I preheat my molds on a hot plate and still pour very generous sprues the first couple pours because the sprue plate is going to cool down the fastest. But once it is hot, it will generally stay hot enough (as long as you are casting at a decent rate) and smaller sprues can be poured.

[Larry Gibson]

If the mould is warmed up; the alloy temp is too low (I cast at 700 - 750 with Lee 6 cavity moulds), and/or the spout adjustment isn't open enough (the alloy needs to come out fast to fill the cavity as quuick as possible) so open up the spout adjustment, and the alloy may need some tin for better fill out (if COWWs add 2% tin for better fill out plus a much better alloy). Don't hesitate to allow a good sprue even if it runs over slightly.

Too low an alloy temp, spout not adjusted open enough and no tin are the 3 most common reasons for rounded bases or bullets casting less than nominal diameter.

Larry Gibson

[williamwaco]

Sprue plate is too cold, the metal is "shying away" from the sharp corner wher the sprue plate covers the base. Cast faster and pour a large sprue on top of the plate, linking all six holes into one big, heavy sprue that will put heat into the sprue plate. When the plate is hot enough that you have to wait six seconds before cutting the sprue to prevent smearing molten metal on top of the blocks, then you can start pouring smaller, pinto-bean-sized sprue puddles to maintain heat.

Gear

+1 Exactly on every word.

.

[geargnasher]

ONE MORE THING: I assumed the boolits were being poured with a large enough stream. One of these days I may learn to never assume, but to cover all the bases I'd have to make every post 5,000 words. Post #5 said "DRIBBLED". If you dribble lead in there, it will make rounded bases, every time, no matter what else you do.

Open the spout adjustment wide-open and drop the stream straight throught hole, or tilt the mold slightly and drop the stream through the side of the hole so it "swirls" inside the cavity and is more effective at purging air from the cavity. The problem with filling the cavity fast to avoid rounded bases is the sudden gush of metal tends to trap air and make hidden (and sometimes visible) trapped air voids in the bases.

Gear

[Willee]

Open the spout adjustment wide-open and drop the stream straight throught hole, or tilt the mold slightly and drop the stream through the side of the hole so it "swirls" inside the cavity and is more effective at purging air from the cavity. The problem with filling the cavity fast to avoid rounded bases is the sudden gush of metal tends to trap air and make hidden (and sometimes visible) trapped air voids in the bases.

Gear

Well now I did it ... I have the El-Cheapo Lee 10lb led pot and the spout is not adjustable.
So ... I tried to drill it out just a tad ... I am sure you know how that ended.
The stopper will no longer seal the hole so there would be no stopping the flow.
That one is spare parts.

What lead pot would you recommend?

Thinking of getting a new Lyman Mag 20 furnace.

Willee .... learning the hard way.

[gefiltephish]

You should be able to get another spout from Lee for cheap. Well, you can for the 20lb, I'm not sure about the 10lb.

[Willee]

You should be able to get another spout from Lee for cheap. Well, you can for the 20lb, I'm not sure about the 10lb.


The 10lb pot has the spout staked in place ... not removable.
I ordered the 20lb pot and it has a replaceable spout.
It has a higher flow also so that might help a lot.

Willee

[geargnasher]

If you only put clean lead in it and don't add crusty ingots or scrape the bottom with a stick, or do anything else that will carry crud/dross/dirt/ash to the bottom of the pot, the 4-20 tends to have fewer dripping problems and a higher delievery volume (and adjustable delivery volume) compared to the 10-lb pot. I think you'll like it, just keep in mind it's a cheap unit and you have to babysit the temperature dial as the level of lead in the pot changes. I've found the thermostats to hold within a few degrees all day long provided the room temperature, draft, and lead level remain consistent. As you use lead and the level drops, the temperature will climb and you have to keep turning the knob down. If you don't have a lead thermometer, get one with the money you saved by going with the Lee, it will be money well-spent and frustrations much reduced in the future if you can tell the lead temp accurately.

Gear

[Bret4207]

Something else to consider- that pic shoes the top surface of the moulds starting to gall. Better get on it fast and clean the bottom of the sprue plate up or it'll trash the mould over time.

[dpaultx]

The 10lb pot has the spout staked in place ... not removable.

The entire replacement 10# pot assembly is only $8 direct from Lee (http://leeprecision.com/pot-pro-assembly.html).

http://leeprecision.com/images/P/p-1090.jpg

You get a brand new pot liner with a brand new spout.

[runfiverun]

nice that's good to know.
i'd still get a 20 lb pot too.
i use the 10 lb pot for single cavity molds only.
the 20 for a different alloy.
and the big magma 40 lb pot for the 2-4 cavity molds that i want a bunch of boolits from.
it is adjustable for pour speed or you can regulate it by hand/eye.