what am I doing wrong?Tons of brown/black crud on top of lead that just keeps coming

[rob99rt]

I'm new to reloading/casting and purchased a Lee 10-lb melt pot recently. Yesterday I tried to do a bit of casting (230 grain subsonic bullets for 300 blackout) and used some WWs, a little bit of 50/50 solder, a few lbs of coarse buckshot, and a bit of linotype in the pot to get myself a BN of around 12 according to the calculator. I took the advice of some folks here and used some sawdust to flux with, mixed it in, scooped out the crud at the top and started casting. After a few minutes I started getting a lot of yellow/black crud on top of the mix, so I scooped it off... Thinking maybe I didn't get all the crud out of the mix, I put another tsp or so of sawdust in it, stirred it around, and scooped off the crud. I was left with "clean" lead for another few minutes... until more yellow/black crud started forming on top. I ended up with a 6" wide, 2" high pile of yellow/black powdery crud that I just kept scooping off every few minutes. That can't be right... Was I running the pot to hot and cooking out the tin and antimony? I think I had it on 6 to 6.5 most of the time, fwiw. From what I've read on here, I might have had the pot too hot and was cooking out the tin that I had added earlier. Not sure... I did get nice shiny bullets out of the mold when it didn't cool down too fast...

I finished my casting session with a bit of frustration (spout kept clogging, mold kept getting too cold with all the wind and the 45-degree temps I was casting in) and per recommendations left a bit of lead in the pot, but there's a TON of yellow crud on the inside of the pot now. Is that lead oxide? Can I get it back into lead metal with some flux/beeswax, or am I going to have to clean it off with a wire brush? I tried scrubbing it out with a brillo pad, but that was an effort in futility. Should I worry about it? I figure that's what was causing the spout to get clogged given it's grainy texture.

Any help would be appreciated. Thanks.

- Rob

[carbine]

Pm sent

[clodhopper]

First off, use another pan to mix alloy and clean up scrap lead.
your bottom pour pot should only recive clean alloy for best results.
A small shallow stainless steel saute pan is cheap at thrift stores or garage sales. Look for one with a pour spout, or just add a pour spout with carefully applied ball peen hammer. You want something easy to scrape the bottom, not to heavy to handle when full of moulten alloy. Use this out doors, use a camp stove for heat. After fluxing, if you do not have an ingot mold just take the pan of alloy and pour it in your bottom pour pot.
The black crud could be graphite fron the shot.

While a mold like a 230 grain .45 caliber bullet is easy to cast with because the cavity shape is short and fat. The lead alloy pours into it and the moulten lead retains the heat well so the first dribbles down the cavity walls have chance to remelt as more hot alloy come into the mold. That makes it much easyer to drop a bullet with smooth surfaces.

A 230 grain .30 caliber bullet is long and skinny.

To get good casting from such a long cavity, you might set the mold on the base of your bottom pour pot to keep it level. if the spru plate is more than an inch or so from the spout put a riser block under the mold.
The farther the lead free falls from the bottem of the pot the more velocity is gains, and the cooler it gets, both of which are working against you.
Still have to leave enough room to get the mold out though. If you aim the stream of lead directly at the fill hole the lead will splash as it hits the bottom of the cavity and splash up on the sides of the cavity, these splatters will bead up and start to harden leaving wrinkles in the finished casting.
So to prevent this,
Aim the stream of lead for the top edge of the bevel in the spru plate. The lead will run down the bevel and fall directly into the nose of the bullet with out dribbling on the side of the cavity. When the cavity is full, let as much lead pile on top of the spru as surface tension will keep there. This gives a resivour of moulten alloy for the casting to draw from as it cools and shrinks. Longer bullets have more noticeable shrink than short bullets.

You have taken what has been for me, one of the most difficult bullets to cast, to start with. Don't give up it is doable.

[khmer6]

I was frustrated with my first session with that same pot. Get a paper clip and needle nose pliers. When it pour slow run the clip through the spout. Mine was pouring way too slow the first pour that the lead in the mold had already cooled and got swirly boolits. You will notice it will pour a whole lot faster. I was doing one cavity at a time cuz it was so slow. Now I'm a production. Madness

[fusionstar916]

I've been told that the gold, sheen across the lead surface is tin and antimony.

It turns gold, then purple/blue, then black. In actuality the particles are getting thicker and harder to see through.
I've just started casting, but in my Lee pot, I leave the saw dust/ash in. I do my fluxing in my big dutch oven pot. When I add new ingots, I scoop out the ash and top it off with new saw dust. This keeps a buffer zone of no oxygen to oxidize my melt. If you keep scooping the yellow stuff off, test your cast boolits. They are softer than the parent ingot.

Once again, I just started so my 2 cents might be totally wrong.

[Duckiller]

Stir your pot with a wood stick. Dowels works great. I suspect that you are trapping burnt sawdust in your lead and it is gradually coming to the surface. Turn your pot on and after it has melted stir with the wood stick. Let the stick burn in the pot, it is fluxing. Keep stirring until you get no more crud on the top of your melt. You really don't want to smelt your lead mixture in your casting pot. A sizeable cast iron pot and a turkey friar cooker is the way to get rid of steel clips on wheel weight and combine various form of lead. Flux and stir your mixture until totally free of crud. Ladle into ingot molds. Get the ladle from a thrift store to stay out of trouble with wife. Put only clean ingots into your casting pot. To clean your pot melt lead in it and stir until all is clean. Be sure to scrape the sides of the pot with your stick. khmer6's paper clip and needle nose pliers is a goodway to keep the spout working. You may need to find a more protected location to do your casting or wait for warmer weather. 45 degree and a stiff wind is not conductive to good casting. It is not even good smelting weather. Reguardless what Lyman and other experts say once you have an alloy you are not going to seperate out the various elements by heating. You may be able to seperate out elements by slow precise cooling. Temp control on a Lee 10 lb pot won't allow this. Bruce B of Nevada posted his experience of trying to sort ot elements of an alloy. He couldn't do it in a metellurgical lab. Some member didn't believe him. Bruce is a very polite and knowledgeable person and you can believe anything he posts. His method of casting soft nosed boolits is worthy of your attention. It is slow but it works. This is a very addictive hobby. With your recent experience you can either drop it and run away or spend the rest of your life looking for wheel weights.

[KYCaster]

The crud is oxides. Not only Sn and Sb, but also Pb. When you skim it off you expose more metal to air and get more oxide. Leave the oxide on the metal and it will slow down the rate of oxidation substantially because you no longer have metal exposed to air.

Better still, after you flux and skim off the dross, add a layer of sawdust and leave it on the surface undisturbed.

Good luck with your casting and welcome to the forum.

Jerry