Diagnose my casting flaws, Lyman 356402

[mvintx]

I've spent the last week doing some casting...50/50 COWW/Pb/2% Sn, PID-controlled, Lee 4-20 pot. The mold is degreased, scrubbed with Dawn, hosed down with Brake Kleen, set on a hotplate to warm, Miha's lube applied to the pins, sprue plate hinge and face and excess wiped off. This is what I get about 20% of the time;
https://i.imgur.com/hcXLUpr.jpg

I've tried pouring into the sprue holes off-center, in the middle, front to back, back to front, temps range from 720 to 780, all in attempt to find the culprit. I've even run the sprue plate without any lube at all, thinking oil might be present. It's got to be something I'm doing because this mold has not acted this way in the past. Please help me before my obsessive-compulsive nature drives me insane.

[onelight]

It looks to me that in-spite of preheating the mold is not up to temp , or is filling to slow.
Wish I had the exact answer then I would not have problems like that :)

[bowenrd]

Try more heat. Alloy is not up to casting temperature.

[JoeJames]

Get the heat up, and try a pressure pour with a ladle. Also put the mold upside down over the pot; I even stick it down into the pot to where the end of the sprue plate is in the melt - just barely in it - then let it sit for a spell.

[mvintx]

Get the heat up, and try a pressure pour with a ladle. Also put the mold upside down over the pot; I even stick it down into the pot to where the end of the sprue plate is in the melt - just barely in it - then let it sit for a spell.

You might have something there...maybe the sprue plate is too cold but you would think at the pace I'm casting (which is dumping the mold after the sprue hardens) it would be hot enough. The flaw is at the end of the pour. Maybe tightening the sprue plate some? I keep it loose enough so it moves with little effort.

Just when you think you've got everything figured out...stuff happens.

[Larry Gibson]

As mentioned, get the heat up. Also hold the spout open and let the alloy flow quickly into the cavity with the alloy roiling back out to form a large sprue, even if the alloy runs off the mould. Keep the sprue plate 1/" or less from the spout. The alloy cools very quickly in a very short distance, especially if casting in cooler weather.

[243winxb]

Lyman IRON molds need NO Lube . Lee's need the lube.

Dawn Ultra ,stencil brush, hot tape water till clean. Wide dry.
Put mold on edge of pot to dry.

Set pot to maximin heat, cast till bullets show some frosting. Adjust heat. Always check as cast bullet diameter. Add linotype (antimony) to increase diameter, as cast.

[JoeJames]

You might have something there...maybe the sprue plate is too cold but you would think at the pace I'm casting (which is dumping the mold after the sprue hardens) it would be hot enough. The flaw is at the end of the pour. Maybe tightening the sprue plate some? I keep it loose enough so it moves with little effort.

Just when you think you've got everything figured out...stuff happens.

No kidding, it took me a spell to get to where I was casting good boolits. But, I was luck enough that my Lee 10# bottom pour stopped up completely, and I started pressure casting with a ladle. Get plenty of melt that way. Shoot, maybe I'm just primitive enough that I need to do it the old way with a ladle with a spout on it.

[bangerjim]

Heat and more heat. Appear to be low temp on alloy and/or mold. Oil/grease in mold is NOT your problem. Scrub all you want, but increasing your heat until boolits are frosty will get you there. Then back off a bit.

"Set on hotplate to warm"..is not nearly hot enough! Take it to full casting temp on the plate B4 ever starting and you will get perfect drops from the 1st one. I do. Every time.

banger

[Conditor22]

Whenever I have problems like this I go back and re-clean my mold

DON"T TIGHTEN THE SPRUE PLATE. Mine move freely. IF you tighten without proper/frequent lubing you will damage your mold and it can cause the sprue plate away from the screw to lift up doing this to your mold.
https://i.imgur.com/K2u3KRO.jpg

Questions,

How many cavities?

When do you apply the lube?

How do you apply the lube? I always start after my first pour [that I pressure pour holding the spout tight to the sprue holes to get the best fill hot or cold] cut the sprue and leave e the boolits in the mold (I use a needle tip bottle to put 1 tiny drop of lube on the sprue plate pivot screw then work the sprue plate back and forth a while and check the top of the mold for any oil that might have worked its way through -- if any oil is present, wipe it off with a paper towel, Then I dampen the tip of a Qtip and put a light coat on top of the mold and under the sprue plate, get a paper towel and wipe everything off (enough oil residue will remain to do the job.) Dump the boolits then use the same dampened q-tip to lightly coat the alignment pins making sure no oil migrates to the cavities.

Do you leave boolits in the cavities while you apply the lube then wipe it off?

What temperature is your hotplate set to? I pre-heat my molds to 400° turning the hotplate on the same time I turn on my pot. IF the area is cool or cold cut a mold sized notch in a coffee can to keep the heat in

How cold is it where you are casting? I like to "purge" the spout (squirt a little lead into the catch container before every pour to get rid of the cooler lead in the spout (which could cause that)

The spots look more like oil contamination than a cold sprue plate.

You could try heating up the sprue plate with a propane torch (like used for annealing brass) I keep one on the casting bench for when the spout cools down too much.

Alternate the direction you fill multi-cavity molds

[HP9MM]

That little circular place on the bullet's base is caused by the sprue plate being cold. I had the same thing and posted it on this site. I was told to create big sprues to heat the sprue plate and it worked out great. Don't be afraid to pour big sprues as they will fill out the mold and keep the sprue plate hot. Remember you are recovering the sprues to put back in the pot so you aren't wasting lead.

[Winger Ed.]

Your alloy is fine, with even more 'goodies' than I would use for handgun stuff.

Don't focus on the thermometer so much.
Like a cell phone--- I may be the last person that doesn't have one,
but folks got along without one for the last couple hundred years or so, and did fine.

Crank up the heat in the pot, as well as the mold, fill the mold as quickly as ya can, and speed up your cadence.
When the boolits frost a little, and/or there is s small hole where the sprue cuts off---
Ease off the pot heat a little.

[JoeJames]

"and/or there is s small hole where the sprue cuts off---
Ease off the pot heat a little. "

That is a good point, wondered about that, just now lightbulb went off in my head. Still in grammar school I reckon.

[fredj338]

Check the molds venting at the sprue plate. Over time they can clog up, no venting can cause this. I also break the edge of the mold halves where they come together under the sprue plate.

[Bazoo]

I think it's contamination from that dadblasted sprue plate lube.

Washing a mould in water is a waste of time in my experience. What I've found that works for me is lighter fluid. With a could mould, spray with brake cleaner of lighter fluid. When it's dry, heat the mould. Then, when it's hot, spritz lighter fluid underneath sprue cutter and the mould top, and block faces. Then close the mould halves, sprue cutter open, and fill the cavities with lighter fluid. It will boil as it evaporates and really clean the cavities. It leaves a tiny bit of residue like smoking the cavities too. Next cast might be bad but normally not.

The beauty of this is you can do it to a hot mould and it doesn't cool down the mould.

I use a carpenters pencil to lube the sprue cutter/block tops and the pins. It can be applied to a hot mould. When it's a cold mould I remove the sprue cutter and color the screw and pivot area thoroughly. On a lee mould that has the pivot heat welded in in place, I take powdered graphite, lift the cutter some so theres a crack, and spill some in.

[gwpercle]

More heat ... things are too cool .

After sprue freezes over ... count to 6 ... then open mould . A properly heated mould and metal should require 6 seconds for the sprue and base to harden without smearing lead across the block top . The count will vary according to how hot or cool the mould / metal is .

After 50+ years of casting I have discovered I get my best boolits with 2-3-4 cavity moulds , a Lyman Ladle with side spout and Pressure Casting .... near about 100% perfect when everything is hot and I leave a generous sprue puddle ... don't short change the sprue puddle ... 5-6-7 second count before opening the mould ... Getting that time just right is critical or you will smear lead .
Gary

[Bazoo]

Of the techniques I've tried, I get the best results with ladle pouring and about an inch of freefall, a large puddle that doesn't spill over the sides or into the other cavity.

[Winger Ed.]

"and/or there is s small hole where the sprue cuts off---
Ease off the pot heat a little. "

That is a good point, wondered about that, just now lightbulb went off in my head. Still in grammar school I reckon.

Hang in there. Its definitely a learning curve.

Before ya know it---- you'll be qualified to teach this class:bigsmyl2:

[Dimner]

You might have something there...maybe the sprue plate is too cold but you would think at the pace I'm casting (which is dumping the mold after the sprue hardens) it would be hot enough. The flaw is at the end of the pour. Maybe tightening the sprue plate some? I keep it loose enough so it moves with little effort.

Just when you think you've got everything figured out...stuff happens.
When I'm having a problem figuring out a molds preference for casting temp, I usually go for the extremes. So first I'll crank the alloy upto 760 then cast really fast. Trying to produce bullets that are defective due to too much heat in the mold. Then I let it cool down some and try 750, and so on and so forth. I don't know why, but some of my molds like it far hotter than others. But of course that introduces other issues like ripping sprue plate cuts. But managing that isn't hard if you have a cooling fan or if you have 2 molds to cast with that like the same alloy temp.

There is a sweet spot somewhere. You will find it. I usually find it by going to the extreme to see what fails and dial down from there.

[Walks]

I never lubed any mold until, I bought my 1st N.O.E. about 5 years ago. And I have used Lee molds for 30+ years.
All I ever did was rub a carpenters pencil over the alignment pins. Same as My Dad, from the late 1940's on.
Old Ideal, Ohaus, Lachmiller just graphite on the pins and proper adjustment of the sprue plate. The 2 stroke oil is a bit easier.
If you're Carefull.
I preheat on a hotplate, turning the mold over on the sprue plate for the last 5 minutes.

[JoeJames]

Hang in there. Its definitely a learning curve.

Before ya know it---- you'll be qualified to teach this class:bigsmyl2:Hopefully, about figured out it is a little bit of science and a little bit of art. My 44 caliber .430" 240 grain cast semi-wadcutters have gotten to where they are more accurate than store bought Speer .430" 240 grain swaged semi-wadcutters anyway.

276273

[onelight]

Very nice . Good shooting

[Win94ae]

I think it's contamination

That is what I thought.

[pergoman]

I bet it is always the cavity closest to the handles and the last one you fill. That end of the mold and sprue plate is too cold. How many cavity is the mold?

[mvintx]

I bet it is always the cavity closest to the handles and the last one you fill. That end of the mold and sprue plate is too cold. How many cavity is the mold?

It's a 4 cavity and it doesn't seem to matter which way I pour...front to back or back to front. Seems like the inner cavities produce the most flaws but it happens to all of them. Based on what I'm hearing from you guys is 1. The sprue plate is too cold. 2. The sprue puddle is too small. 3. Crank up the heat.

[farmbif]

I don't know what is causing your problem but I noticed the last mold I got from miha, took a whole bunch of work to get clean and remove all the traces of whatever kind of cutting/machineing lube he is using. much more difficult to get clean than any previous mold I had gotten from him.

[Mk42gunner]

I've spent the last week doing some casting...50/50 COWW/Pb/2% Sn, PID-controlled, Lee 4-20 pot. The mold is degreased, scrubbed with Dawn, hosed down with Brake Kleen, set on a hotplate to warm, Miha's lube applied to the pins, sprue plate hinge and face and excess wiped off. This is what I get about 20% of the time;
https://i.imgur.com/hcXLUpr.jpg

I've tried pouring into the sprue holes off-center, in the middle, front to back, back to front, temps range from 720 to 780, all in attempt to find the culprit. I've even run the sprue plate without any lube at all, thinking oil might be present. It's got to be something I'm doing because this mold has not acted this way in the past. Please help me before my obsessive-compulsive nature drives me insane.

I may be wrong, but it looks like a venting issue to me. None of the bases are what I would call sharp and well filled out. The big honking flaw in the base is just more of the same.

Were are you casting? Outside or in a poorly heated outbuilding, or inside where you don't have to wear a jacket? Ambient temp does make a difference in how a mold performs, especially if you normally pour with an air gap between the nozzle and the sprue plate.

Graphite from a pencil works to prevent the sprue form sticking to the sprue plate, so does soapstone; maybe even better. I've used both, it just depends on what I find first when I need it.

Robert

[243winxb]

Sprue plate to tight on top of mold? Trapping air.

The fill holes in the sprue plate are to small for the lead stream comming out of the botton spout. I had to open a 38 Saeco mould.

[Bazoo]

Leave as large a puddle for each cavity as possible without it spilling helps fillout and also helps a little oxide to move to the sprue.

[Conditor22]

Either venting or (most likely) a cold sprue plate.

make sure the sprue plate swings freely but you can't see light between the plate and the mold

[mvintx]

Whenever I have problems like this I go back and re-clean my mold

DON"T TIGHTEN THE SPRUE PLATE. Mine move freely. IF you tighten without proper/frequent lubing you will damage your mold and it can cause the sprue plate away from the screw to lift up doing this to your mold.
https://i.imgur.com/K2u3KRO.jpg

Questions,

How many cavities?
4-cavities
When do you apply the lube?
maybe 10 or 15 minutes before starting to cast
How do you apply the lube?
With a q-tip, I 'touch' the locating pins, side of the sprue pivot bolt and then wipe the underside of the sprue plate and then with a rag, wipe off the lube

I always start after my first pour [that I pressure pour holding the spout tight to the sprue holes to get the best fill hot or cold] cut the sprue and leave e the boolits in the mold (I use a needle tip bottle to put 1 tiny drop of lube on the sprue plate pivot screw then work the sprue plate back and forth a while and check the top of the mold for any oil that might have worked its way through -- if any oil is present, wipe it off with a paper towel, Then I dampen the tip of a Qtip and put a light coat on top of the mold and under the sprue plate, get a paper towel and wipe everything off (enough oil residue will remain to do the job.) Dump the boolits then use the same dampened q-tip to lightly coat the alignment pins making sure no oil migrates to the cavities.

Do you leave boolits in the cavities while you apply the lube then wipe it off?
I have not tried that
What temperature is your hotplate set to? just numbers on a dial but my mold reads about 300 degrees with an infrared thermometer I pre-heat my molds to 400° turning the hotplate on the same time I turn on my pot. IF the area is cool or cold cut a mold sized notch in a coffee can to keep the heat in

How cold is it where you are casting? It's been in the 40s I like to "purge" the spout (squirt a little lead into the catch container before every pour to get rid of the cooler lead in the spout (which could cause that)

The spots look more like oil contamination than a cold sprue plate.

You could try heating up the sprue plate with a propane torch (like used for annealing brass) I keep one on the casting bench for when the spout cools down too much.

Alternate the direction you fill multi-cavity molds tried that to no avail

thanks for the tips, though. At higher settings on my hotplate, the bottom of the mold will read 500 degrees and the top around 350. I was afraid I might be overheating the mold and turned the dial to a lower setting. Can you warp an iron mold??

[mvintx]

I may be wrong, but it looks like a venting issue to me. None of the bases are what I would call sharp and well filled out. The big honking flaw in the base is just more of the same.

Were are you casting? Outside or in a poorly heated outbuilding, or inside where you don't have to wear a jacket? Ambient temp does make a difference in how a mold performs, especially if you normally pour with an air gap between the nozzle and the sprue plate.

Graphite from a pencil works to prevent the sprue form sticking to the sprue plate, so does soapstone; maybe even better. I've used both, it just depends on what I find first when I need it.

Robert

soapstone eh? Haven't tried it but I'll stick that in my repertoire.
I'm casting in my barn. No heat, temp in the 40s and wearing my insulated coveralls. Sometimes I'll run my diesel blowtorch heater so my teeth don't chatter.

[guy_with_boolits]

Im a beginner caster and I found it quite challening to keep the mold hot enough. Its easy to get the lead hot enough, and I would recommend keeping it below 750F because above that vapors start to form (there is literature on this)

The mold on the other hand..my 6 cav aluminum lee mold seems to take forever to get up to temperature by keeping it dipped in the hot lead, and even then there are clear differences between one end and the other.

I can usually tell if things are hot enough by hot fast the sprue solidifies. If its right away, not hot enough. If its a few seconds..there we go

[onelight]

I don't find dipping a corner in the pot works well on 6 cavity molds it will help on the 1 and 2 cavity aluminum but I think the 6 are to long . A hot plate or laying across the top of a full pot and covered with aluminum foil seems to work better for me to preheat.

[bangerjim]

Don't corner dip any longer!!!!!! Use an electric hotplate to bring the molds to 100% casting temp before ever starting to cast. If you like to cycle different molds as some do, keep the other molds at the ready temperature on the plate. Once you get a plate, you will wonder where it has been all your life!

I get perfect drops from the 1st pour by using a hotplate preheat.....not just WARM!!!!.

[farmbif]

ok I'm sold, the hotplate is getting moved from the camper to the casting shed.

[243winxb]

No dipping of iron molds.

[Mk42gunner]

I sympathize with casting in a poorly heated barn, this year I am relegated to using my Mom's wash house kept barely above freezing. I had some of the issues you are having with rounded bases, cured in my case by pressure filling the mold. Just a different motion than I am used to doing when casting.

Increasing the melt temp may help.

I am hesitant to use a hot plate on the same electrical circuit. My old farmhouse was originally wired with two conductor 14 gauge wire, and I don't want to overstress the circuit.

My new house, that I am slooowly building, will have two circuits at my casting bench so I can at least try using a hot plate to preheat molds.

I much prefer to cast, not smelt, inside in comfort as opposed to trying to do a decent job in near freezing temperatures.

Robert

[canyon-ghost]

I started out with Lyman 2 Cavs. When I got the Lee 6 cavity, I keep it hot by hesitation. With all cavities full, give it 30 to 60 seconds longer than when the spruce hardens. This lets the heat go all through the mold! To cool, when you empty it, wave that hot mold opened up through the air! Cadence in casting can be your friend, if you pay close attention.