Lead inside Lyman Mold

[Colorado4wheel]

Why is this happening? I have a reaccuring spot on one cavity. While inspecting it I found lead around the ring for the lube grove under two other cavities. I have polished the mold a couple times. Bullets drop out fine, bullets look fine other then in those small areas. What if anything am I doing wrong. This is a Lyman 4 cavity 9mm 147gr mold.

[Bullshop]

Just a guess so dont hold me to anything. I believe initially the mold had something in it that acted as a flux and caused soldering at those points. This is one good reason to keep the tin content to a minimum in your alloy, tin+lead+solder.
With your meehanite alloy Lyman mold it will be easy to clean out. With an aluminum mold because aluminum is softer it would be more of a problem.
I have had the same problem occur when buying used molds and was able to clean up the soldered area buy bringing the blocks up to casting temp and brushing the problem areas with a bronze brush. After the soldering is removed do a complete clean & degrease of the blocks.
I know you said you polished the cavities but even so the very corners of the grooves in the blocks may not have been touched.
Before you start casting you may want smoke the cavities to help prevent the re start of the soldering process again. In the very few instances I have had this problem I was able to get it stopped this way. There have been some folks posting here about treating cavities with Kroil. That could be a possibility and perhaps you should check up on those posts. Please report back and let us know how it goes.
BIC/BS

[longbow]

+1 for what Bullshop says about the bronze brush if the lead is stubborn.

I would try brushing cold and if you can't get the lead off then heat the mould up until the lead melts then brush and wipe with a paper towel to remove the molten lead.

If you don't have a bronze or brass brush a small piece of brass, bronze, copper or aluminum rod or bar can be used as a scraper since they are all softer than the iron but harder than lead. Even a wood stick might work.

After the lead is removed. what I would do is continue to heat the mould at about the melting temp of lead until it heat blues. After that it should not re-solder at least easily.

Alternately use cold blue, or as Bullshop says, smoke the cavities to avoid re-soldering and the casting heat should re-blue them after a while.

Not sure what you mean by polishing the mould but if you are using something other than a lapping boolit you risk making the cavities uneven or rounding edges. Also, every time you remove the blue, lead is more likely to re-solder at the shiny part. You need to blue it, smoke it or use a mould release to stop the soldering effect.

Longbow

[sagacious]

Also, every time you remove the blue, lead is more likely to re-solder at the shiny part. You need to blue it, smoke it or use a mould release to stop the soldering effect.

Longbow

Absolutely right. Lead alloy with tin in it is especially prone to soldering to plain old shiny steel. Happens. The fix advised above will solve the problem. Good luck.

[Bret4207]

A hot mould and a sharp stick will usually fix the problem. Then rub the suspect area with a pencil and that will ensure no more stickies.

[badgeredd]

I had a used mold that had the same problem. I happened on a post that suggested using a #2 pencil to help boolit release so I heated the mold quite hot and treated the offending area with the graphite pencil lead and it was cured. Just a thought...

Edd

[JIMinPHX]

With your meehanite alloy Lyman mold it will be easy to clean out.

Meehanite??? Those molds don't seem hard enough to have that kind of material present. How do you figure that the material is meehanite?

That aside, I would probably try a little kroil to help get the sticky lead out of there.

[Echo]

Meehanite??? Those molds don't seem hard enough to have that kind of material present. How do you figure that the material is meehanite?

It's my understanding that Lyman has always used meehanite for their molds. I may be wrong...

[Colorado4wheel]

I got the lead out. I will smoke it really good and try again. Thanks everyone. Besides this one issue this mold works great now.

[JIMinPHX]

Wow, you learn something new everyday. I just looked up Meehanite in some metallurgical references. It turns out that there are different varieties of it. The one that I had used in the past seemed much harder than a Lyman mold. That's what threw me off. Sorry to have been a doubting Thomas & sorry to have hijacked this thread.

Regards,
Jim

[montana_charlie]

Absolutely right. Lead alloy with tin in it is especially prone to soldering to plain old shiny steel.
Since Colorado4Wheel finally 'got the lead out', I thought I would chat a bit over the concept described above. I am not saying sagacious is wrong, but I am saying I have my doubts. Those doubts don't all come from casting experience...some come from soldering experience.

To start, solder (any kind) does stick best on 'shiny stuff', but only because shiny stuff is clean...that is, free of oxidation.
Yes, smoking a cavity should prevent leading, but everybody knows that smoking a mould is a bandaid for other problems.
Good moulds don't need it...ever.

Second, while silver solder is very useful on steel items, tin/lead solder is about useless. It has been used on things like gutters and flashing, but primarily formed a water resistant 'plug' to keep them from leaking. It was not a high-strength bond which added structural integrity.
When used in automotive bodywork, it is simply a 'filler'...which will fall out if not mechanically secured in position.

Finally, common solder contains a large percentage of tin...40% or more. Start reducing the tin content below a very high level and the solder quickly becomes useless. This is easily seen when soldering electronic components with 60/40 solder. Spend just a little too much time applying heat...enough to 'burn out' the tin...and you get a poor solder joint. No bullet alloy even approaches the tin content of solder.
The heaviest users of tin are (probably) the BPCR shooters with up to 6% (16-1 alloy).
They typically run tons of metal through a shiny iron mould with no complaints of 'soldering' in the cavity, and only a few of them would even consider smoking a mould.

I agree that, when alloy gets stuck to a mould, it can be difficult to remove.
But I don't believe it's a function of having tin in the mix...thereby turning it into 'solder'.
I think it occurs - in a cavity - when hot alloy is allowed to contact a 'clean' surface which has not been preheated enough to make it form a microscopic layer of oxidation. (Bluing is also 'oxidation'.)

I think that casting with a cold mould, as a means of bringing it up to temperature, is a good way to cause the condition. I think it occurrs when the interior of the cavity gets hot enough to let the alloy stick...but before enough heat has been generated to make the oxide layer.

Smoking the cavity can apply a carbon deposit as a substitute for the oxidation. But, it's a bandaid for the real 'cure'...and may reduce the size of the bullet.

That's my take on this subject.
Please note that I use "I think' and 'I believe' throughout this post. That means it isn't intended to be taken as 'hard fact'...even though it is 'firm opinion'. So, while discussion may be appropriate, argument is not.

CM

[Bullshop]

All sounds good to me. I dont smoke molds but I did suggest it in this case as a means to begin the oxidation precess and prevent the alloy from sticking until then.
I do think though that certain things used as a preservative on molds may act as a flux when cooked on and cause the problem. When I have had the problem it always seems to be in the very edge or corner where the cleaning process may have missed.
I may be wrong but I too get to think it.
BIC/BS

[Colorado4wheel]

I cast a 20lb pot through the mold this afternoon. It took a little while for it to start casting right. But once it got going it made the best boolits it's ever made. I figured out the temp the mold likes and I m casting at 750F. Very nice. Thanks everyone.

Read the post about smoke/oxidation.

I think smoking it helped. I think it helps the mold get up to temp and start to work right with out the blueing. Most of the mold insides are starting to blue. Still silver color under the lube grove. I don't know what to do but keep using it and hope for the best. I will probably mark it up with a pencil just to be safe. Eventually it will blue over and be safe again.

[sagacious]

Since Colorado4Wheel finally 'got the lead out', I thought I would chat a bit over the concept described above. I am not saying sagacious is wrong, but I am saying I have my doubts. Those doubts don't all come from casting experience...some come from soldering experience.
...

CM
Charlie,
Thanks both for sharing your thoughts, and the thoughtfulness of your reply. I too was once a doubting Thomas that tin could cause lead alloys to stick (even solder) to steel-- but in fact it can easily happen. Allow me to relate some of my findings on this topic, and please forgive the length of this reply.

I once had a problem with lead castings sticking in a steel push-through mold. My first response was to clean the cavities/bores carefully and thoroughly. The sticking continued. Let me tell you, this was a seriously vexing problem.

My second thought was that the cavities/bores needed polishing. So, I polished them very carefully. However, the sticking became much worse. How could this be?

I considered my alloy. I had intended to pour soft lead castings, and in practice knew I was by the ease with which the sprues were cut. I have considerable foundry experience, and was well-versed with casting/alloying lead long before I ever poured a lead bullet. I was sure I knew my game well-enough. This seemed a dead end.

Upon hearing my problem, a colleague stated confidently that the tin content of my alloy must be too high, and this was the cause of the castings sticking in the bores. This conclusion seemed laughable-- lead/tin alloy sticking to steel? Ridiculous!

But, just to be sure, I double-checked my casting alloy. Sure enough, I had accidentally been using some lead alloy with tin content, and not pure lead. Could this really be the cause? One session using known pure lead confirmed this conclusion.

Now, upon reflection, that tin content might cause sticking to a polished steel surface seems almost painfully obvious to me. Tin cans (tin-coated steel) use a coating of tin because tin has a very high affinity for iron and the tin coating forms a true alloy with the steel. Old batches of linotype often contain some iron content, as repeated melting in steel pots causes the tin to scavenge iron. And a little closer to home, the LEE lead pots are not warranted for use with pewter. Why? Because the high tin content can actually attack/dissolve the mild steel liner in the pot. Note that no flux is necessary to cause iron scavenging by tin. And recall that old 55gal steel cans used to be soldered with a lead/tin alloy that formed a structural, high-strength bond. Even today, Pb80/Sn12/Sb8 and Pb80/Sn18/Ag2 and several others are commonly used for securely soldering steel, and those are minimal tin alloys. Lead/tin bonding to iron/steel? Yessir.

The rub is this: The higher the tin content, the greater the affinity of that alloy for iron/steel. Hight tin content can actually scavenge/dissolve iron, lesser tin content can solder securely, and lower still can stick. When a steel surface is freshly polished, sure-as-shooting, even a low-tin lead alloy can stick to the polished steel surface.

Anyway, just some thoughts for you to mull over, or keep in the back of your mind. Regards, and good shooting! :drinks:

[Bret4207]

I cast a 20lb pot through the mold this afternoon. It took a little while for it to start casting right. But once it got going it made the best boolits it's ever made. I figured out the temp the mold likes and I m casting at 750F. Very nice. Thanks everyone.

Read the post about smoke/oxidation.

I think smoking it helped. I think it helps the mold get up to temp and start to work right with out the blueing. Most of the mold insides are starting to blue. Still silver color under the lube grove. I don't know what to do but keep using it and hope for the best. I will probably mark it up with a pencil just to be safe. Eventually it will blue over and be safe again.

Smoking is one of those things I do as a last resort. Like Charlie said, it's a band aide. To avoid that get the mould really, really clean. I like to use chemicals, others use boiling water and soaps. Whatever you use, get the oils out. When it's clean you still will find that many moulds need to "cook" a bit to get the trolls and goblins out of the pores of the mould. For me, nothing beats casts fast and hot and letting that moulds get nice and hot, hot enough that a sprue takes 15-18 seconds to coll. Several rounds of high temp casting seems to cure most ills for me. But- should you try this be advised you'll be in primo territory for sprue plate galling. Be very careful with this.

After getting the oils out I do my best never to let any petroleum or wax type product ever get near the cavity again.

[Colorado4wheel]

Smoking is one of those things I do as a last resort. Like Charlie said, it's a band aide. To avoid that get the mould really, really clean. I like to use chemicals, others use boiling water and soaps. Whatever you use, get the oils out. When it's clean you still will find that many moulds need to "cook" a bit to get the trolls and goblins out of the pores of the mould. For me, nothing beats casts fast and hot and letting that moulds get nice and hot, hot enough that a sprue takes 15-18 seconds to coll. Several rounds of high temp casting seems to cure most ills for me. But- should you try this be advised you'll be in primo territory for sprue plate galling. Be very careful with this.

After getting the oils out I do my best never to let any petroleum or wax type product ever get near the cavity again.

So that begs the question, what do you store you mold with to protect it? I don't want it to rust.

[Calamity Jake]

So that begs the question, what do you store you mold with to protect it? I don't want it to rust.

After the mold has cooled put in 50cal ammo can with good seal an add a descant pak. No rust in 30 years is my experance.

[Bret4207]

So that begs the question, what do you store you mold with to protect it? I don't want it to rust.

I used to store them in a 20mm ammo can. Now I keep them in an old dead refrigerator with a 15 watt light bulb in it and a large desiccant pack. Every so often I'll get a little light surface rust, just a dusting. Happens when I lay my sweaty paws on a cold mould. We're talking 80-some moulds here, it's no real problem.

[Colorado4wheel]

I uses this thing about 1 a week at least. I have it stored in a Zip Lock bag right now, with some packs I took out of my Vitamins. I live in Colorado so it's pretty dry here. Not sure if it's best to seal it in bag like I did or just leave it out in the open. I don't want to do anything to the mold now that it's clean and working right.

[deltaenterprizes]

According to my latest version of Lymans "Cast Bullet Handbook" eleventh printing in 2002 on page 54 the caption under picture #1 "Cold-rolled steel blocks of a special alloy are purchased by Lyman Products for its complete line of moulds."
I was surprised by this when I read it.

[montana_charlie]

sagacious,
I commend you on stating your case in a clear and conversational tone. However, my Thomas-ness is just too pervasive to allow me to shed my doubts so easily.

I'm certain that I use twice as much tin as over 60% of the casters posting here. Like many others, I don't allow any substance resembling smoke or release agents on mould faces or in cavities.
Yet, I am (like most) never troubled by 'soldered moulds'.

You were faced with a 'soldered mould' once. Based on the advice of a collegue, you came to believe that tin content was the culprit. I can think of other possibilities, but we can leave it alone.

As for the tin plating on steel cans, I think tin was chosen for it's resistance to corrosion...not it's affinity for steel. The plating process can 'coat' steel with almost any metal desired.

But, I will do some mulling from time to time...especially if I get a brass mould.
Now, THAT is something I would wonder about getting 'soldered'...

CM

[sagacious]

Montana Charlie,
I wouldn't think of asking you to change your mind. You are correct, tin was chosen for it's non-reactivity with food acids, and low toxicity, but the tin coating still forms a true alloy with steel.

Regardless, soldering steel is a simple matter. As a test, I just polished a piece of steel with 1500grit paper, and soldered it first try with 40/60 rosin-core solder. Not just a blob of solder perched on steel-- the solder actually wets, grabs, and flows. This is visible in the photo below. It's not just stuck on-- it's soldered. I make silver jewelry, so soldering is old-hat for me, but this is the same way that double-barrel shotguns were 'soft soldered' using a tin solder. Very old technology, but as effective today as ever. Brownells still sells tin solder for soldering steel.

One is not expected to commonly experience soldering on a steel mold, as the oxide layer usually prevents this. A polished steel surface is a different matter. Even so, that one does not experience something does not mean that others have not. I have experienced lead/tin alloy sticking to steel-- not just once, but many times, and it continued until I the alloy problem was remedied. This is what I meant by saying it was a particulary vexing problem. My intent was not to convince you, but only to inform.

I am aware that even a photo may not suffice. You may wish to put this to the test yourself, or just keep it in the back of your mind for a rainy day.

Regards. :drinks:

[montana_charlie]

This is visible in the photo below. It's not just stuck on-- it's soldered. I make silver jewelry, so soldering is old-hat for me,
Soldering is old-hat for me, too, but our areas of experience differ considerably.
Mine, while extensive and very precise, was strictly in the electronics field.
That limits me to those metals used for components (and tools), and leaves me with no real grasp of the materials you deal with.

Your photo certainly shows no sign of being a 'cold joint', which means you brought the steel to just the right temperature before applying the solder.
Can you say what that temperature was?

My Thomas-ness is weakening but my doubts have been with me so long I would suffer severe discomfort if I let them go too quickly. So, I will say that your 40/60 is still too rich in tin to compare it with the typical bullet alloy found on this forum...2% or less...and the rosin which allows it to melt and cool without oxidation will not be present inside a mould cavity.

However...
Your mention of the difference between a polished surface and an oxidized one slightly brightened a bulb which has been burning dimly in the back of my mind...where you keep suggesting I should store your information.

The new mould I am currently using is the first on which I have tried Bullplate.

Because the directions say to apply to a hot surface, I laid the thoroughly cleaned sprue plate on my coffee cup warmer until it was too hot to handle...but probably still below 200 degrees - and not hot enough to create decent oxidation.

I have had some tiny grains of alloy start to adhere to the top of the plate as I cast with the mould. I attributed this to the Bullplate wearing thin, and showing the need for a new application.

But...I am (now) thinking that it would be better to clean the whole thing, removing any (ulp!) 'soldered-on' alloy, then bring it all the way up to casting temperature - to get the oxidation layer well formed - before applying the new Bullplate coating.

After all, the mould is not experiencing the problem...just the sprue plate...and the plate IS a polished surface, unlike the mould, itself.

If it appeared (a few lines above) that I seemed to say 'you're right' just disregard that. We manly men can't be easily swayed by fast talkers...

CM

[MT Gianni]

So that begs the question, what do you store you mold with to protect it? I don't want it to rust.

I store mine in the bottom drawer of an old school desk. My climate is dry enough that rust isn't a problem.

[sagacious]

MC,
The steel was heated to about where I would preheat a brass connection before soldering-- hot enough to make the flux flow but not smoke. By intent, there was nowhere enough heating to cause any discoloration of the steel. Took all of 5 seconds to solder that steel, honest injun. Just warmed the thin steel (maybe 2 seconds max), touched the tip of the solder to it, and then I directed the small flame onto the solder and workpiece. Melted on and flowed immediately. I braze stainless almost every day, and don't recall ever trying to use Pb/Sn to solder steel, but this was almost too easy. I reckon I learned something from this test that I'll put to good use in the future.

If certainly do not expect to just take my word for it. But since I did get challenged (politely) on this topic, and since I have demonstrated from several angles that tin will indeed readily solder steel at low temps, and included evidence for all to see and independantly double-check, I think the challenge now lies on those who publicly disagree to provide actual support for why tin cannot possibly cause sticking on a newly polished steel surface.

I would suggest the best advice is that 'seasoning' a steel mold after polishing/lapping and before casting is a good way to avoid the potential for sticking of lead/tin alloys, and is likely one of the main reasons that manufacturers recommend mold seasoning before use.

As I said, I don't wish anyone to abandon their suspicions and suffer from the bends by surfacing too quickly! I hope your mold pours as well as you're anticipating, and that you have the best of luck with it. Thorough cleaning of the s-p and re-application seems like the best course of action.

Cheers, good luck and good shooting. :drinks:

[Colorado4wheel]

How hot is that? I use a metal probe thermometer on the outside of my mold. It cast best right around 300F. Give or take 25F. I am sure the cavity is much hotter then that but I aint scratching it with my metal probe to find out.

[sagacious]

C4W,
Are you asking how hot the steel workpiece was? Not very hot. Steel starts to show yellow oxidation at around 420*F, and this solder melts at 460*F. One can see in the photo that the steel was soldered rapidly and without any discoloration because the solder grabbed on fast. Preheat was certainly less than 400*F.

[MtGun44]

RCBS uses Meehanite, not Lyman. Lyman uses steel, and very soft steel at that.

RCBS keeps the sharp details far better than Lyman. My opinion is that RCBS
quality is absolutely tops. Don't always like their designs, many are fine, and
REALLY wish they'd do some 4 cav molds, but their quality is excellent and I
think the Meehanite is a clearly superior material.

Bill

[Colorado4wheel]

It's funny we bash Lyman around here and Praise Lee. Lee molds are utter cr@p compared to Lyman in my experiance with both. Lyman uses Heat Treated Steel. Lee uses aluminum so soft it scratch's, dents, bends if you talk to it wrong. Maybe RCBS is a better mold. They don't make a 4 caviety. Saeco is twice as expensive for a 4 cavity.

[Colorado4wheel]

C4W,
Are you asking how hot the steel workpiece was? Not very hot. Steel starts to show yellow oxidation at around 420*F, and this solder melts at 460*F. One can see in the photo that the steel was soldered rapidly and without any discoloration because the solder grabbed on fast. Preheat was certainly less than 400*F.

Yes, that was my question. So, if you can solder at 400f and my mold works best between 275F and 325F on the OUTSIDE of the mold by the handel it seems very logical to assume the mold temp at the cavity is easily 400F.