Contamination ???

[Skip62]

Anyone know what causes this contamination? These are the worse examples, just to get a good photo. I'm using a Lee Pro bottom pour, Lyman 175 TC die. Is it something in the lead, or the cavity? If I open the mold and look it's there before I drop.

Thanks

[Sensai]

Looks like inclusions. I'd remelt and flux a couple more times. Be sure to scrape the bottom and sides real well. I'd empty and clean that bottom pour, too. They have a habit of hanging on to junk at the spout.

[dbosman]

What Sensai said.

Scrape the bottom and sides of the pot. Gently of course so you don't splash yourself. That's easy to do.
All the dirt will float, except the stuff that is under the lead, or held against the sides by the lead.

I use a stainless steal food service tray to smelt in. I ladle out of that to make my ingots. There comes a point where I can't ladle anymore out, so I let that cool, then tip the cooled slab out, for future smelting. I'm always astonished by the amount of dirt that was still under the lead.

[Larry Gibson]

What alloy?

Larry Gibson

[kbstenberg]

I have started to empty the pot every time I cast. And clean the bottom and sides. Like stated above. There is always a lot of residue even after only 1 full pot of alloy. An it only adds a couple of minutes to your casting time.
A positive side affect is my 4-20 drips a lot less. Kevin

[Skip62]

Great, thank you. Hopefully I can mess with it tomorrow. I was using Marvelux, but I read last night that wasn't a good idea, so today I just used sawdust. I did notice the pot was MUCH cleaner from the sawdust today. I'll scrape more carefully, and empty the pot as suggested.

Larry the alloy is some .45's from Penn bullets, and Keads Hard Cast bullets. Stuff I had laying around.

[shooter93]

Clean the pot out with boiling water. I do that time to time or anytime inclusions show up.

[Calamity Jake]

The inclusions won't hurt anything, I"ed shootem

Flux good the next time casting.

[Inkman]

I'd lube those up and shoot em in a heartbeat.

Al

[runfiverun]

that is oxide inclusions.
it is from oxidized alloy in the melt.
I really wouldn't worry about the amount you have there being In the boolits.
but i'd be looking at reducing them back into the melt.

[Skip62]

I was going to shoot them, but I would like to make better looking bullets, don't know why, I'm going to poly coat them anyway... I just always have to make things better and want to learn, so I'll remelt for practice since I'm waiting for lead.
So, cuz I'm a visual guy, I don't really understand what oxides are without a picture of something. I went out and heated up my half full pot and saw dusted and scraped several times, then empty the pot. Here's some pictures, any thing you can add about what looks normal or not would be appreciated.

Here's the pot half full after 3 saw dustings


Here are the ingots I made with that. I see that scum on the top as I'm pouring, is that normal is that the oxidization I see on the bullets?


Here's the empty pot, anything I need to do to it?


Thanks for the help.
skip

[snuffy]

I was going to shoot them, but I would like to make better looking bullets, don't know why, I'm going to poly coat them anyway... I just always have to make things better and want to learn, so I'll remelt for practice since I'm waiting for lead.
So, cuz I'm a visual guy, I don't really understand what oxides are without a picture of something. I went out and heated up my half full pot and saw dusted and scraped several times, then empty the pot. Here's some pictures, any thing you can add about what looks normal or not would be appreciated.

Here's the pot half full after 3 saw dustings



Here are the ingots I made with that. I see that scum on the top as I'm pouring, is that normal is that the oxidization I see on the bullets?


Here's the empty pot, anything I need to do to it?


Thanks for the help.
skip

The surface of that molten lead SHOULD look like a mirror.

There's more to fluxing with saw dust than just dumping some on the melt, then skimming it off. You HAVE to get the molten lead in contact with the charred saw dust. You just wait until it's charred then get to stirring to bring the melt up to contact the char. You can even dip lead from the bottom of the pot, then pour it back through the charred saw dust of the surface.

Sawdust will clean better than a wax or oil, AND it removes stuff like zinc, aluminum, copper and a few other contaminates that cause what you're seeing.

[runfiverun]

you also need an oxygen free atmosphere to reduce oxides.
something with a high carbon monoxide atmosphere works just fine.

in the top pic.
the stuff in the bottom right hand corner is what you got on your boolits.

to clean the pot just boil some water in it.
then take a wire brush on your drill and buff out the sides of the pot.
wear a mask of some sort and don't breathe the dust.
I would do a quick lap of the pour spout and rod while you got it there.

[stocker]

In the top picture it appears to be oxides on the surface of the fresh melt. How hot are you running the pot? Can you knock the temperature back a bit and see a brighter surface after fluxing?

[Skip62]

Snuffy, I thought it should like a mirror, if I draw my spoon across it is, but hazed over again immediately. I was taking the spoon down the sides, and then back up and holding lead in the spoon and dropping it back down again, but think I now know what you mean about mixing the lead into the char. That helps, thanks.

runfiverun, not sure I understand how to create an oxygen free atmosphere over the pot. Can you elaborate?
As far as the stuff that got on my bullets, that helps, now I know better what to look for.
Boil the pot? like put the thing in a pot of boiling water??? OH come on, I got somebody with that. I did remove the rod and clean it good. I'll work on the pour spout.

Stocker, not sure how hot the pot was, cuz I just wanting to empty it to clean.

Ok, so am I supposed to scrape the gray off the top and remove, or pour it back through the saw dust. This, I think, is where I'm getting hung up. What to leave, what to remove from the pot. I read Dr Fryxell's page about it, but with out pictures to know what I'm looking at I'm lost.

Thank you all, it's a pleasure to have found this site. Your all most helpful, and knowledgeable.
skip

[runfiverun]

work the charred sawdust through the melt and the melt through the sawdust.
it is carbon after it chars off.
the process is carborization.
the carbon monoxide on the surface is easily made by a fire
http://www.youtube.com/watch?v=0mtg0Yl91ww
this might help you remember.

[454PB]

I've used Marvelux for many years and never had inclusions like yours. How much do you use?

I flux well, then leave the dross on top of the melt as a form of oxygen barrier.

Even very clean alloy will "skin over" with dross in short order and lose it's shine.

[44man]

Much is common with the surface. Not important if you bottom pour. There you have a problem. There is crud that sinks to the bottom of the pot, flux will NOT raise it. You can do a million things at the surface but nothing will get rid of the stuff that sinks. I would never believe the junk sinks but i use all kinds of alloys and dump my pot often. The last is a pile of crud. Black junk, dust.
Why does it sink?

[Skip62]

work the charred sawdust through the melt and the melt through the sawdust.
it is carbon after it chars off.
the process is carborization.
the carbon monoxide on the surface is easily made by a fire
http://www.youtube.com/watch?v=0mtg0Yl91ww
this might help you remember.

OH DUH!!!! that makes sense. I'm old and slow

454PB, just sprinkling a little on top like the can said.

I boiled the pot, wire wheeled 'er clean, and boiled again. Hopefully tomorrow I can give it another go. I went into the alloy forum, and read all I could about sawdust, I think I'm starting to get it. Will soon see.

Thanks for all your help.

[williamwaco]

I do not shoot bullets with inclusions.
Personal opinion. I have never done any accuracy testing with them.
It seems to me that they would be lighter and cause the bullet to be unbalanced.
I also know that things that are obviously true frequently are not.

When you get through with your getting acquainted with the process and the pot, I recommend you NEVER let the pot go empty. Every time I do that I get junk in the downspout and have fits with inclusions after refilling it. I never let the level of the alloy get less than one inch deep in the bottom of the pot. This practice will also speed up the melting process next time you fire up the pot.

When you really need to empty the pot, pour ingots until the alloy level in the pot reaches around one half inch. Then ( using your heavy gloves ) pick the pot up turn it upside down and dump the last of the alloy into an empty ingot mold. This way the crud on the top doesn't get sucked into the downspout.

Do not overlook the above advice that all kinds of undesirable "stuff" can be found below the surface and even at the bottom of the pot. Even wood ash from the sawdust can float around under the surface until it winds up in the surface of a bullet.

I make no pretense of knowing how something that light can sink into a pot of molten lead but I know it can. I find that vigorous stirring is critical to getting clean metal.
When I flux, I stir repeatedly until slag and ash no longer appears. This can take as long as 60 seconds of stirring.

Someone above recommended bringing up alloy and pouring it back through the flux. This works well for me.