Lead Casting - Part 1

By soundguy, Apr 6, 2017 | |
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  1. soundguy
    In my last article I gave an overview of metallic cartridge reloading. Reloading in itself is a very full stand alone hobby. However there are plenty of other hobbies that can significantly complement it, and still others that could benefit from it. Lead casting for example makes a great companion hobby to reloading. ( And if you enjoy muzzle loading firearms, you will want to learn how to cast to save $$ ). Part 1 of this article will deal with finding your lead and preparing it for use, and Part 2 of this article will cover actually putting that lead to use making bullets,


    Lead casting at it’s most basic is heating lead or a lead alloy, then pouring the molten lead into a cavity mold to produce an object. ( plenty of fishermen lead cast their own sinkers ).


    I have only been casting just going on 2 years now, however started researching it a few years ago, knowing it would be a good companion hobby to reloading. For anyone thinking they might want to get into casting, I recommend doing the same. Research, Research, Research, online and in books, thru contacts at clubs or being mentored by an experienced person locally. As with reloading, there are a few different paths you can take, and thus different equipment and styles. Above all, remember safety. Lead melts at about 622’F, Tin melts at 450’F, and raw antimony melts at 1167’F. These are the main alloy metals you will be using. There are others, but that’s left to the more advanced caster. Since you will be working with molten metal of this temperature, personal safety practices and protective gear will be needed. Also, keep in mind that you are working with toxic heavy metals. Don’t eat, smoke, drink, etc, while working with your lead. The white powdery oxide is also dangerous on lead. Wash any exposed skin thoroughly after exposure. Avoid breathing the fumes that smelting and lead casting produces, including the fumes from burning flux materials. Always cast in an area with plenty of open air ventilation, and not in confined spaces. Be very careful about getting water or other liquids into your lead pot. Water droplets can fall into your pot and turn into a small steam explosion instantly, tossing hot lead streamers everywhere. This is why protective gear like gloves, aprons, and appropriate eye protection is needed, perhaps even breathing protection depending on the amount of fumes your pot gives off. These warnings are not meant to be exhaustive, but rather serve as additional information that you can use along with other safety information you will find in reference materials, such as the Lyman cast bullet handbook. For those looking for research material, I highly recommend the following: Lyman cast bullet handbook, ( available in print ), and as an online resource, use your browser to search for “ From Ingot to target: A cast bullet guide for hand gunners. Also, the ‘ Cast Bullets’ publication from the NRA is a useful tool. Many other reference books and articles I have read refer back to these 3 works.


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    Ok, now that you have been warned about working with hot metal, hot tools, etc, and have been given a few paths to explore to find other casting reference material, lets get to it.


    Finding your lead.


    This may actually be the most expensive and challenging part. In the good old days, you could stop by tire stores and service stations and get buckets of wheel weights for free or very, very cheap. Now with new regulations, these deals are few and far between. When I started casting, only one Mom N Pop location still had wheel weights you could scrounge, and now a year later they are gone. Other sources could be your local junkyard or metal recycler. Some won’t sell metals, some will. Occasionally you can find lead during demolition of doctor’s offices, if they had an xray machine. They usually used thin soft lead sheeting in the walls around the room. Roof jack / vent covers in some parts of the country are also made of soft lead. Some sail boats also use lead as keel ballast, so a derelict boat may be a source. Scrap lead can sometimes be found when shooting ranges clean out their backstops. Failing this you will have to actually purchase lead. There are many options here as well. Commercial producers such as Rotometals will sell lead ingots and pigs ( large bulk ingots ), as well as other alloying materials, such as pure tin, antimony, and pre-alloyed ingots of linotype and lyman #2 alloy. You can also search online forsale forums and find people that are selling range scrap lead or wheel weights already in ingot form. Recycled nuclear medicine isotope shielding lead is another source. Typically this lead is allowed to set and decay for long periods in case it is contaminated with any of the isotopes it was carrying, then it is sold to a recycler, who may then further decay it, then sell it. Lastly, try to avoid wheel weights that are zinc. For most casters, zinc is your enemy. There are advanced ways to use zinc in your alloy, but you can find out about that once you have a good grasp on casting. I’ll talk more about zinc later on in the smelting and melting section.


    Now you have you lead, but… what do you actually have?


    Pure lead has a Brinell hardness of 5 ( BHN ). Once you start adding other metals to lead, to alloy it for shooting, it’s hardness increases. About the only shooters using soft 5BHN lead are muzzleloaders, because it would be hard to stuff something harder down a bore or into a revolver cylinder. Here is where your alloy metals like tin ( SN ) and antimony ( SB ) come into play. I won’t list out all of the various BHN numbers of possible alloy combinations, but I will touch on a few that you might see commonly. Lead, as we discussed is 5. Linotype ( from older printing machines ) is about 22. Lyman # 2 alloy ( a very common and widely used alloy ) is about 15. Melted wheel weights tends to vary, since stick on wheel weights tend to be softer and clip on tend to be harder, but the pots I have smelted, and the sources I have used for WW ingots tends to yield about 12. Range scrap lead falls in the same category of ‘it can vary’. 22 rim fire and muzzle loader lead is softer, and it gets harder as you go from pistol, to magnum pistol to rifle, as well as jacketed rifle and pistol with harder or softer cores. The range scrap lead I have been buying has averaged 10. If you are going to get into casting as a real hobby, I recommend getting a cheap lead hardness test kit. Lee makes a kit that is easy to use and gives you fairly accurate results. It can be found at places like ebay and amazon for about $66. If you find yourself with soft lead, but needing harder lead, then you need to buy either harder lead to mix in, such as adding linotype to straight lead, or directly making your own alloy by adding tin and antimony, etc. Here are a few of the common alloy percentages by weight, expressed as % lead, % antimony and % tin. Lyman #2 90/5/5 Linotype 84/12/4, wheel weights, 95.5/4/0.5.

    Why all this talk about hardness. Without getting too far into it, the more feet per second, and pressure a cartridge has, the harder the lead it needs. For example, here is a basic guideline to what you might want for BHN of lead for specific projectiles in specific applications: standard revolver 800-1000 fps, 16kpsi 8-14, +P loads, 1000-1200 fps, 20k psi 10-16, magnum revolver 1200-1500 fps, 35k psi, 12-20, ‘and larger’ 1400-1800 fps, 50k psi 16+.



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    Working with what you have.


    Ok, you have lead, or lead alloys, perhaps some of it is scrap, etc, now you need to make useable ingots to feed your melting pot. Melting down your scrap lead and cleaning it is called smelting. I use a cast iron skillet and a propane burner. I put my cut up lead shielding, range scrap, etc in there, then start the burner. This lets the lead heat up and if there is any water in it, it lets it flash off before the lead melts.

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    Remember.. no water in your lead.. and never put cold lead into your pot or smelter. Once you have melted lead, you should flux it. If it is pretty clean scrap, once may be enough, if it is range pickup and solid wheel weights, it may need up to 3 fluxings. First, once it is melted, use a tool like an old metal salad fork or slotted stirring spoon to remove foreign materials like steel clips from the wheel weights, and copper jackets from jacketed bullets. ( you can recycle these at a scrap yard ). Add flux material to your smelting pot and constantly stir your lead. The ash is lighter than your lead, and once you stir it, it will ‘float’ on top, where it forms a powdery waste called dross. You skim the dross off. Flux can be commercially bought, Frankford arsenal sells some, or you can use clean sawdust, or my favorite, candle wax ( your flux may produce plenty of smoke and a small flame, so plan accordingly. So now you have clean shiny fluxed lead in your smelting pot. You now need to pour small ingots that you will use to feed your production pot. I use commercial lee ingot molds that make ½ and 1 pound bars. Ingot molds can be had for as low as $ 15.00. Lyman and others sell ingot molds. Some people find old aluminum or cast iron cornbread or muffin baking pans and use those. Just be careful not to use ‘non stick’ type forms, only plain aluminum or cast iron. Commercial ingot molds may tell you to ‘smoke’ or ‘candle’ the molds prior to use. This means to use a candle and hold the mold above the candle so that soot is deposited lightly along the molds cavity surfaces. Then you wipe out the soot. This makes the mold release better. There are commercial release agents, but there is debate on if the release agent is building up in the mold excessively. Pour your ingots, alloy to cool, pop them out of their mold and keep going till you done. Note.. lead is HEAVY. My smelting pot is a small skillet. It might look too small to use, but it will hold 10# lead when it is full. 10# lead is heavy when you are trying to pour it into ingot molds and not make a lead plated mess everywhere.



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    Ok, now you have lead or lead alloy ingots plus any alloying metals you may need to sweeten your mix. For instance, you can purchase tin nuggets that you can use to add to your mix if it was a low tin allow. Tin lowers the surface tension of lead and helps make your bullets fill out with crisp corners. It also slightly hardens lead. Antimony hardens lead very well, and works hand in hand with tin. Lead/antimony/tin make fine bullet casting alloys. ( there could be another entire article on hardening lead, lead alloys, heat treating and water dropping. Save those topics till you have a little casting under your belt ).

    Stat tuned for part 2 to be published next week!

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