Restarting casting after a break. Problems......

[cal44walker]

Hi Guys,

Hi from Denmark! I've cast a lot of bullets for blackpowder some years back using roof lead and alloying it with tin scavenged from an industrial soldering machine. These bullets worked OK in an RCBS 45-70 500gr mould and perfectly in an 45 cal Paul Jones mould I got hold of.

So.......got back into shooting and now I have a 38 Vaquero and a 32-20 Wcf Winchester to load for. Here's what I'm doing:

-Mix of range lead scavenged from the pistol range (mostly 22lr bullets) Alloyed with about 8% of the solder scrap.
-Gas heated pot with 20lbs of metal (800 degrees F).
-Lyman moulds for the 32 and 38

After having broken both moulds in and trying various pouring techniques with a ladle I am getting very random results. Some bullets fill out, others have 1 side of the bullet with incomplete filling of the grease groove corners. When I pour the lead in, the problem with incomplete filling reduces somewhat, and when I hold the ladle right on the mould and force feed it using the wieght of the lead in the ladle I get a combination of perfect and badly incomlpete grease groove corners.

I'm also getting a HUUUUGE amount of dross and particulates on the surface when I flux. I mean a LOT. I'm guessing that by using dirty range lead and unknown purity solder I'm making life hard for myself. I can't really see anywhere that my technique is incorect. I had much better results with the roof scrap so I'm guessing it a material problem. Any suggestions?

cal44walker

[I'll Make Mine]

You probably should consider adding a smelting step between "range scrap" and "bullet casting" -- melt the range scrap, flux and skim, then pour into ingots; this will separate the good lead alloy from dirt, jackets, and such and let you leave the stuff you couldn't skim in the (separate) smelting pot, so you can start casting from clean ingots.

Beyond that, there's probably enough antimony in the range scrap (since some of it is likely cast instead of jacketed or commercially swaged lead) that your melting point might be higher than your old alloy; you might, then, need to run the pot hotter, and almost certainly need to get the mold hotter so the lead doesn't solidify before it can fill the mold.

[Bardo]

I would run your Lead cooler. I cast at around 650 F. I think the hotter the faster it oxidizes the lead on top. I like to run the lead cooler with my molds up to temp. And if that solder is mostly tin you have more then enough in there. That alloy would be close to what Elmer Keith used. Im not sure how much antimony is in 22 slugs but probably not much.

Bardo

[runfiverun]

bout 1.5% antimony in the 22's.
you need to clean the range scrap in a separate pot.
turn down your heat, 800 is too hot, it is causing your oxidization issues [especially the tin]
heat the molds up more before you even start casting,try dipping the edge of a mold in the pot long enough for the alloy to not stick anymore.
then start casting,pour a generous sprue on top of the plate and don't even look at the boolits for the first 10 or so pours.

[MikeS]

When using an alloy with tin in it once you go over 750F you're negating any advantage adding tin gives you, and the tin starts to oxidate much quicker. I would run your alloy much cooler, 100F over the temp where the alloy is fully liquid is all you need. I usually cast right around 650F when using either range scrap, or Lyman #2 alloy, and it works well for me. You also probably need to get the mould hotter, you might consider getting a small single burner electric hot plate to preheat your mould(s). I use a hot plate, and I usually set it on Medium, and place my mould on it at the same time I turn on my casting pot. By the time the pot is up to temp, and ready to go the mould is preheated enough. By doing this I can usually get keepers on either the first, or second pour. Also, make sure there's no oil in your mould(s) before you start. You might want to give the mould(s) a good scrubing with dish washing detergent and an old toothbrush. After doing that, dry the mould, then preheat it on the hotplate, that way if there's any left over moisture it will go away during the preheating step.
How do you flux your pot? Try using a wood based flux, either sawdust, or flaked wood. You can get pine shavings at a pet shop (they sell it as hamster bedding), they work really well for fluxing. If you've never used a wood based flux before you'll be amazed at how well it works. If you're going to use a bottom pour pot you can leave a layer of the wood based flux on top of the melted alloy, it will help keep the heat in, and keep the alloy from oxidizing on the top as well.

[cbrick]

By all means turn down the heat or save the tin and don't bother putting it in. Very little to no Sb in 22 rim fire lead, possibly up to 1.5% probably a bit of tin but not a lot.

Always smelt in a pot other than your casting pot. Flux your smelt vigorously with sawdust. When you think you have it well fluxed and clean flux it again and then pour your ingots. Now when your ready to cast you have reasonably clean alloy that didn't gunk up your pot getting it clean. Once your casting pot is up to temp and your ready to start casting flux with sawdust again.

A fair part of that huuuuge amount of dross you mentioned could be your tin because of the 800 degrees. Past 750 degrees tin cannot do what you put in the melt to do, reduce the surface tension of the alloy by reducing oxidation allowing good fill out of the mold and not only the surface of the pot but the stream of alloy into the mold also. The more past 750 degrees not only the less effective the tin plus the tin itself oxidizes rapidly past 750.

When you where casting for the 45-70 and using just the roofing lead (pure or nearly pure) 800 was probably fine but with a Pb/Sb alloy 700 degrees is all you need or want.

Rick

[cal44walker]

Well, tried several things. 650 degrees........700 degrees.......750 degrees.......800 degrees. Completly cleaning the mould , different pouring techniques...etc etc etc. Nothing came even close to consistently working. The mould temp was constant and I had bullets with sharp edges on 1 side and not the other. Then the other way round. Then a few good ones. I am pretty sure I've got contaminated lead. The results were better the hot I have any roof scrap left. Sand blast the pot and ladle and try again. Very frustrating.....:(

[Le Loup Solitaire]

Hi and welcome to the forum. Much good advice has been already given to you. Firstly 800 degrees or more is too high heat. 700-750 should be the range to work in (generally). Aluminum molds require a little more heat and or slightly faster casting; if you get some frosting you can adjust for that later after these issues are cleared up. It seems that you have a lot of crud in the mix that you are trying to work with and that has to be cleaned and fluxed out. The creation of an "ingot step" is a good idea to "cut things down". One of the symptoms you are describing is that of zinc contamination....it will mess up surface tension of the alloy and create incomplete bands on the bullet or part of it. The zinc has to be at least diluted until its value/amount in the melt goes below the level at which it disturbs the fillout of the bullet. Until you achieve that you will be struggling with the problem all day/night. There are several good fluxes/ways to flux the melt and this is something that cannot be overdone, at least until things are working alright for you...so flux continually until you have all good bullets dropping consistently well. As for tin, you don't really need more than 2% in the mix and with some antimony involved it will produce sharp, well filled out bullets. This is a process of balance and it sometimes requires stubborn patience. When you get it together your casting will be a successful source of joy. Check in the forum for write-ups that deal with the zinc problem elimination and follow advice given. You will win this one; just stay with it. LLS

[runfiverun]

you should see the zink show up as an oatmealy looking gunk just under the surface at about 700-f alloy temp.
a high calcium content in the alloy can also cause similar issues.

[Cadillo]

Thoroughly clean and degrease your mold, and then preheat it as previously mentioned. Like you I ladle cast, and I use a modified turkey fryer rig fired by propane. I heat my moulds by putting them on top of the burner's grate, to the side of the flame, and the moulds are heated while the alloy melts. Works great!.

If that doesn't get it done, add some more tin. I use enough tin that I cast at about 625F or under with an iron mould. Brass moulds require a little more heat.

First thing though, is like several others said, you need to smelt and cast in separate pots at separate times. To do otherwise is to make a lot of trouble for yourself, and since casting is a labor of love, you have to make it enjoyable rather than frustrating, lest you lose interest.

Keep everyone here posted!

[fouronesix]

44walker,
Something is wacky! There could be some unknown combinations of elements in that alloy. And, casting those small caliber bullets can be real buggers sometimes. First, I'd just melt the alloy that is in the pot and pour into ingots and set aside and label it as unknown.

Then start over with a known alloy. For light loads no need to exceed a BHN of 12 or so (fairly soft alloy). If you can get something like the near pure soft roof flashing lead or near pure plumber's lead to start with then add a little tin you'd be better off. Solder is a good source for tin but currently there are so many types of solder, you have to pay close attention to what is in them- obviously a tin/lead only solder is what to look for.

Start by melting the pure then add small amounts of tin alloy until you at least get up to 9-10 BHN. Small amounts of printers type metal can be added to kick the BHN higher if needed. During this process you can flux with a little lube or sawdust. Stir and scrape the pot and stir and skim until all the dross is gone and just a light sheen layer shows on top (normal clean alloy). Then regulate heat to about 725 F to start and begin pouring and casting in a cadence that keeps the mold hot. If pouring with a ladle vary the amount in the ladle, how long the ladle dwells on the mold, etc. Then try to duplicate what is working for the perfect castings. Sometimes multi cavity molds are nearly impossible to regulate to drop good bullets from each cavity on each pour using a ladle. Then possibly a bottom pour technique is called for to speed the process to keep the alloy hot enough and the mold hot enough or the temperature difference between the two regulated for best castings dropping from each cavity. Perfect bullets out of each cavity and each pour in some multi cavity molds can be nearly impossible. When I run into that I just find out which cavity or cavities are working best and use the mold that way. Slower production beats frustration/no production every time. Good luck!

[Wayne Smith]

You are working with an unknown alloy, dirty, and new molds. Too many changes at once. Go back to your starting point that worked. Empty your pot of this alloy, fill it with the alloy that worked well with the 45-70. Cast a few of those to confirm this.

Now try your new molds, heated up and re-cleaned. Let us know what happens. This will clear up the issue of the alloy vs a poorly vented mold problem. Your issues can be caused by a poorly vented mold.

Once you have confirmed that the molds are good, re-fill with the questionable alloy, cleaned, and cast 45-70 boolits! You know that mold works, you have confidence in it. Then go to the smaller molds.

In following this procedure you will have isolated each possible element and determined where specifically the problem exists. Once that is known we can help you.

[cal44walker]

Hi Wayne

Thats exactly what I am in the process of doing. :) I'll pick up the roof lead I had after New Year and try again with that. And I'll get some tin so I know exactly what I'm putting in the mix.

cal44walker