Cleaning Lead

[justindad]

I recognize those inclusions, but mine didn’t always disappear with sizing. I always wondered if those were from dropping spruce cuts into the pot while metal oxides were floating. Do you use a bottom pour & are you dropping in spruce cuts or culls?
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Is the level of antimony here higher than you are used to using?
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At the end of my casting session, I clean my alloy and empty the pot into the ingot mold… because of these inclusions. Then I flux again at the beginning of the next casting session, so ingots are cleaned several times. This helped my purchased 92-6-2 alloy.
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I remember when I received the 8lb ingots and melted them down into 1lb ingots - a whole lot of trash was stuck to the inside walls of the pot. This is the cheapest source of lead with 2% tin I can find (regardless of antimony content), so might be a “you get what you pay for” kinda thing.

[flatnose]

I am using a bottom pour and I am not dropping in the sprues as I go but I have in the past. Cant say I noticed a difference although i might not have noticed it. As i said earlier it is always worse with a full pot and gets better as it gets lower but still can turn out one with this anytime. As far as the amount of antimony all I can go by is the certs. I have drained the pot and cleaned it . Fluxed many times with beeswax, pine sawdust, marvelux. Beeswax actually seems to clean it the best but I can still have this problem. Is this trash in the lead or something else. I dont know.

[jsizemore]

Looks like antimony freezing on the surface of your bullet. Antimony is a bit high so you could cut it in half with an equal amount of lead and bring you back to COWW alloy with 1% tin already added. Looks like your temp is fine with good fill out. If you add the lead you may want to run your mold temp a little hotter. Running your mold hotter without adding the lead will cause more and larger patches. Alloy 100°F above liquidus is about right. I set my PID on 700°F and call it good with that alloy.

[dondiego]

A spruce is a species of tree. A sprue is what is discarded from the top of the mold when casting a bullet.

[jsizemore]

A spruce is a species of tree. A sprue is what is discarded from the top of the mold when casting a bullet.

Spell check knows spruce but not sprue.

[flatnose]

couple more pics for anyone that might know the problem
This is an extreme example. Sometimes the problem is almost gone. I just cant seem to figure out what it is that makes it not do this.

[dondiego]

Spell check knows spruce but not sprue.

Sorry!

[farmbif]

its difficult to tell by pictures but are the inclusions actual voids or is it more like a different colored material imbedded in the lead, is it possible to pick the pieces out with tip of a pocket knife or is it just a discoloration. and does this happen with different molds or just the one? also if you were to cut a bullet in half are these "inclusions" thought it or just on the surface. I guess the bottom line is, how do they shoot and is the cast weights of these bullets consistant or are the weight of them all over the place.
an xrf test could be helpful to figure out exactly what is in the alloy.

[Bazoo]

Those would be considered as good bullets if they were mine. Minor surface imperfections doesn’t a reject bullet make. Filled out good.

I get bullets that look like that if I use not too clean alloy and I don’t keep the alloy skimmed. Ladle casting though. My experience is that, a very large sprue left that doesn’t run over the mould sides allows most of that to float out of the bullet into the sprue. A small sprue, or a sprue that pulls off the mould or into the adjacent cavity will not draw the scum out of the bullet.

I’d guess your problem is the heat isn’t high enough. If it happens less with an almost empty pot, that means the alloy is hotter. Maybe the temperature control on your pot is going out.

[flatnose]

If I turn the heat down this almost completely goes away. Almost all of my molds, the bullets wont fill out at a low temp. This really starts at about 750 +. I have molds from accurate, arsenal, lyman and MP. Also using a pid. This problem wont be on every bullet. I have emptied the pot and cleaned it. I have scraped and fluxed with almost everything you can think of. None of it seems to be over .001 deep although sometimes it will look etched. I guess I am down to trying some new alloy.

[farmbif]

if it is just on the surface is it possible some lubricant or something on the mold is causing it? just thinking out loud her. maybe check the alloy by taking a spoonful out of the pot and pouring it out on a clean. surface and see if there are still spots in it.
I know the last mold I got had some sort of super duty cutting fluid residue on it that took a whole bunch of work to get cleaned off.

[jsizemore]

Clumps of antimony freezing on the surface. Lead temp too high. Turn down the pot lead temp to 700°F. Adding more lead to the mix will let you run a higher melt temp if you feel the need to do that. If they fill out (looks like that's not a problem) than why keep cranking up the temp?

[John Boy]

Bring melt up to casting temperature …. Drop flux on top of lead …. Burn smoke off with a match … stir the flux DEEP into the melt with sides of the pot scraped and keep stirring until the gray dross rises to the top and floats on the top of the lead
.. Skim off . Repeat steps = Done
Borax is a good flux

[flatnose]

Clumps of antimony freezing on the surface. Lead temp too high. Turn down the pot lead temp to 700°F. Adding more lead to the mix will let you run a higher melt temp if you feel the need to do that. If they fill out (looks like that's not a problem) than why keep cranking up the temp?

As I mentioned earlier 700 will almost stop this problem but I cant get fill out at that low temp.

[jsizemore]

Never saw that in any of your posts. You did say the problem was about gone when you turned the temp down.

[triggerhappy243]

Attachment 299157

ok here is a picture of a real bad one
sometimes it is on only the body and when you size them even .001" it is gone
anyone have any suggestions?

see if you can find a little muriatic acid somewhere. place a drop onto the side of that bullet. if it foams, you have zinc.

[bruce381]

Looks like antimony freezing on the surface of your bullet. Antimony is a bit high so you could cut it in half with an equal amount of lead and bring you back to COWW alloy with 1% tin already added. Looks like your temp is fine with good fill out. If you add the lead you may want to run your mold temp a little hotter. Running your mold hotter without adding the lead will cause more and larger patches. Alloy 100°F above liquidus is about right. I set my PID on 700°F and call it good with that alloy.

Yeah agree add some lesser alloyed lead I do that and it goes away

[Charlie Horse]

is it possible it has zinc in it? Only way to test it yourself is with muriatic acid. Then try xrf testing.

How do you test for zinc with muriatic acid? What's xrf?

[Charlie Horse]

I may be all wet here, but I've never had this problem to speak of, and I've never fluxed with sawdust. Always wax. Candle wax.

[triggerhappy243]

how do you test for zinc with muriatic acid? What's xrf?

muriatic acid has a chemical reaction with zinc. The metal foams aggressively if their is zinc in the lead.
A few drops on your lead ingot is all that is needed. If it foams like a freshly poured rootbeer, the ingot contains zinc.
Xrf is an electronic method to analyze the lead ingot thru radiation. It detects all of the metal alloys contained in the ingot.