What is this sludge? And why is my lead breaking like cookies?

[Stopsign32v]

291786291787

Trying this from my phone so I hope the pictures show up. But best I can describe this is heavy sludge. I flux with sawdust to get a glass like top to my lead pot but in doing so I remove this heavy sludge. Just going by weight I can tell I’m losing a good bit of lead which makes me sad. Is this needed?

Second question is lately I’ve been noticing my lead on top of the sprue plate is fracturing apart in pieces rather than being a solid mass of lead. I also noticed one of my boolits had a crack in it. Looking at the fractured lead from the plate best I can describe it is the inside looks like powdered metal. My hardness right now is at 10.4 BHN

[ih772]

Zinc contamination?

[JonB_in_Glencoe]

What alloy?
what temp?

It doesn't look like Zinc contamination to me, maybe you are running your pot too HOT?
...Zinc contamination looks like Oatmeal and as soon as you remove the Dross, more forms...unless you crank the temp real high...like over 800º high.

[Cap'n Morgan]

I have quite a stash of tin-based babbit metal - about 80% tin content. When melting, it will form a sludge in the transition phase, somewhat similar to your pictures.

[Dusty Bannister]

Your photo shows the thermostat setting at the highest position. It appears to be a relatively new pot, but may have scale build up if you failed to clean your alloy in a different pot. You mention saw dust, but do you also use a wax or perhaps other type of flux to help clean the alloy? It might be helpful to ID what you think your alloy might be. If the alloy temp is excessive, the sprue will take longer to become solid so it will fracture while still mushy. Same with the bullet if you are casting long skinny bullets. That information might be beneficial.

When you add candle wax, expect it to flash ignite so use care where you do this.

[mehavey]

Do youself a favor... flux with candle wax* as above... not sawdust.
Bet you will find a world of difference


*
(even better and pea-sized lump of 50-50 ALOX/Beeswax bullet lube)

[Rcmaveric]

I couldnt tell what temp you are at. Some alloys get a grainy transition stage specially those with antimony. Raise the temp to 800*F and flux with wax (bee, candle, wifes stash of smelly goodie).

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[Bent Ramrod]

Yes, try the candle wax, and keep stirring until that crusty stuff has disappeared and any impurities are no longer clumped, but look like loose black dirt.

I set the smoke on fire with the candle, and let it (held in one hand, horizontally) continue to burn and drip while stirring with the other hand. If the smoke stops burning, I relight it with the candle; if the candle goes out, I light it off the burning surface of the pot. I stir until I get a mirror surface with black specks.

The black dirt I wind up skimming off has a minimum of metal in it, and it looks like smooth metal, rather than that oatmeal consistency your pictures show. If you had zinc in it, the whole pot would look like that; an uncastable slush that never fully liquefies.

[Baltimoreed]

What Bent Ramrod said. ^^

[Springfield]

You really need some sort of thermometer.

[zarrinvz24]

I use a small marble's sized chunk of paraffin wax, put it on top, let it melt on top and then stir it using a wooden paint stick. It will smoke a lot, and if you use too much wax it may catch on fire.

[mehavey]

stir it using a wooden paint stick.
Since I dipper-pour, I just run the dipper upside down to
the bottom of the pot and back to get the liquid wax all
through the melt. Rarely do I wind up w/ anything but
sooty dross left on top to scrape out with a teaspoon.

[dkf]

I find sawdust doesn't cut it for flux a lot of time. So I am not a fan of it. I get some of that separation on some of my alloys and add some candle wax from an old candle I have, mixes it right in. Makes good bullets then. Mine doesn't have zinc in it, I know that for sure. What I end up removing from fluxing is not the color of lead or tin.

[MOA]

Sawdust flux burned black and ready to be removed.

https://i.postimg.cc/0NV8LxyV/20211110-152643-HDR-1.jpg (https://postimg.cc/PL8swgZD)


After removing all the burnt sawdust and after fluxing with pariffin.
https://i.postimg.cc/RhzZm203/20211111-150619-HDR-1.jpg (https://postimg.cc/FdD4gW3m)

[ShooterAZ]

I use sawdust and paraffin wax when smelting, works great. I only use beeswax in my lead pot though, it's much cleaner. It's kind of difficult to pin things down when we don't know what alloy you're using or the source of your lead. I'm also guessing that you're running it too hot.

[414gates]

Looks like tin on a cold melt.

The first time I melted down scrap, I got that, and I unknowingly scooped it off. It was with my prototype melter, and the heat output was too low.

Later on I realised the melt was too cold for the tin to go into solution, so it floated out.

Not sure what the power output of those little electric units are, but you'd do better with it if you kept it half full. It takes a lot of juice to keep all that lead at temperature, maybe more than the melter can handle with a full pot.

[oley55]

I'm with the "too cold" crowd. I bet most of it can be fluxed back into your melt, so don't throw that dross out yet.

[Stopsign32v]

I'm with the "too cold" crowd. I bet most of it can be fluxed back into your melt, so don't throw that dross out yet.

This makes sense I think.

And in the pictures the temp is set at 7, not max. Max is 9

[charlie b]

Yes, that is probably tin. I will sometimes see that same kind of thing as the pot heats up. Leave it all alone until your pot is well up to temp. Then flux it. I initially use beeswax, then put a layer of sawdust on it to keep oxides from building up.

[Stopsign32v]

So would you guys add the sludge back into the pot, up to temp, and then flux? I finally have the BHN where I want it so if I add this what we think is tin, my hardness will go up (which I do not want).

Should I toss it or keep it for future use as tin? (assuming that's what it is)

[oley55]

So would you guys add the sludge back into the pot, up to temp, and then flux? I finally have the BHN where I want it so if I add this what we think is tin, my hardness will go up (which I do not want).

Should I toss it or keep it for future use as tin? (assuming that's what it is)

it takes MANY percents of tin to change hardness. However, if your lead is making good well filled out bullets save the tin for another time.

edit: by the way, what method are you using to measure tenths of a BHN? just curious about the 10.4 bhn. My drafting pencils don't. LOL

[Hannibal]

[QUOTE=Stopsign32v;5299915]So would you guys add the sludge back into the pot, up to temp, and then flux? I finally have the BHN where I want it so if I add this what we think is tin, my hardness will go up (which I do not want).

Should I toss it or keep it for future use as tin? (assuming that's what it is




I'm not sure if you're aware of this, but if you are checking BHN within a week after casting it'll be harder in 4-6 months. Sometimes a lot harder.

[Stopsign32v]

it takes MANY percents of tin to change hardness. However, if your lead is making good well filled out bullets save the tin for another time.

edit: by the way, what method are you using to measure tenths of a BHN? just curious about the 10.4 bhn. My drafting pencils don't. LOL

The LEE hardness tester.

[JimB..]

Get a thermometer, check temp, report back.

I will generally save anything metal and toss it into my next big melt for ingots. Usually isn’t much, but whatever.

I don’t get tin floating out when the alloy is too cold, I just get mushy alloy.

[Stopsign32v]

Here are some boolits that come from this.

https://live.staticflickr.com/65535/51685421233_12d5bd663b_c.jpg (https://www.flickr.com/gp/113193676@N08/hp10f3)

[charlie b]

I'd keep that stuff. If is is just unmelted alloy, then see if you can test the hardness of it. Then use it as you see fit.

[414gates]

.. so if I add this what we think is tin, my hardness will go up (which I do not want ...

My understanding is that tin helps the lead fill the mould better, so it increases the fluidity of the molten lead.

Antimony is what increases hardness.

If your melt casts well after you removed that excess, you don't really need it, so put it aside for later.

[GregLaROCHE]

How close are your individual boolit weights ?

[JimB..]

Deformation at the nose means something, are they all like that?

[JonB_in_Glencoe]

So would you guys add the sludge back into the pot, up to temp, and then flux? I finally have the BHN where I want it so if I add this what we think is tin, my hardness will go up (which I do not want).

Should I toss it or keep it for future use as tin? (assuming that's what it is)

Yes, needs better job of fluxing.

[Stopsign32v]

Deformation at the nose means something, are they all like that?

Yea Jim, something to do with the mold. Every single one is the same exactly on the nose.

[rockshooter]

small nose defects, esp on pistol bullets, have no effect on anything.
Loren

[BadDaditood]

That’s where you drill the hollow points ;-)

[dearslayer]

I had the same as you last week when I tried to melt a few items of what is supposed to be pewter. I had two different items, both with " English Pewter" engraved in the bottom One was very thin and melted no problem and this other one that was very thick and heavy that would not seem the melt. I was trying to melt it all to cast into bullets so it would be easier to add to my melted lead when I wanted 2% tin. I did keep it because I had planned to pose the same questions on here regarding the same. 292383292384292385

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[JimB..]

English Pewter should be tin, copper and antimony. When you tap it does it thud or ring?

[gwpercle]

Don't flux with sawdust only ... add some wax to the wood , there is something the wood doesn't get but wax will flux it .
I use a three step , wood shavings (I have pencil sharpener access) , bees wax (or paraffin ) and then to be certain a little Marvelux commerical flux . All three do the best job .
Start the melt at 8.5 or 9.0 and be careful of the wax ... if at or over 400 degrees the wax will flash into fire and burn ...be careful , the flashing and burning can be scary ...do not use but a little wax with the wood shavings and stir with a wooden paddle . I follow up with Marvelux and stir and then skim off all dross . Two small fluxes is better and safer than one large flux .
Gary

[Dom]

Flux with UN-salted lard, or lard rendered from fat from your last game animal. Works as good as the best flux you can buy. This was advice came to me from LBT bullets years ago. It works.

[SteveM54]

I've noticed that sometimes the color of the top coat is a dark blue. Anyone one know what that is?

[Chaparral66]

Keep it and add it to the next mix batch. Make sure the temp is high enough and keep pushing the junk down into the molten metal and you will be surprised how much of the goo will reduce to just ash, dirt or schmutz. I recently dumped (on purpose) my dross bucket into the melting pot and when finished I only had about 1/4 of the crap to skim off. Temperature and patience are the key.

[Chaparral66]

The dark blue or purple usually means you are running too hot. Check the actual temperature of the molten metal. A thermocouple is an indispensable tool. The IR guns are great, except they do not show an accurate temperature when bounced off the shiny silver surface. A black surface is the best indicator. Maybe float a 3" square of steel on the surface for the best results with IR.

When I have a pot melting odd shapes, WW, rage scrap I run fairly hot, but once it is all molten I turn down the heat to just keep it hot enough to ladle and pour.