Reclaiming lead from used pellets
by B.B. Pelleiter
Many of you have indicated an interest in this topic, so today we'll do it. This is what you do after the shooting is over.
I shoot anywhere from 10K to 25K airgun shots each year--mostly in the course of my profession, but sometimes for pure recreation, as well. I shoot into several portable bullet traps as well as outdoor dirt berms, and a couple of those traps catch the pellets for recycling. So, every year or so I have several pounds of lead waste to recycle. When this report began I would estimate the total weight of material was 20 lbs.
For this report, I also had about 40 lbs. of wheelweights to turn into ingots, but that's another story. The pellets went very well--the wheelweights did not.
Melting lead is low-tech
If you watched the movie The Patriot, you got to see lead-melting first-hand. That's about as technical as it gets. You need about 600 degrees which a campfire can provide and the lead gets all puddly pretty quick. All we have to do to reduce the pile of pellet waste is to do the same thing, magnified a few hundred times.
Like many of you, I save my pellet waste from the Outers bullet trap. I also have another bullet trap that gets cleaned out every other year or so. I used to own a plumber's furnace that made short work of the lead, but I stupidly let it go and have never been able to replace it. Heck, you can't even find one on eBay anymore. People have been dumbed-down to the point that you have to look for a "lead melter" to find one. I'm not kidding! That's what they call plumbers furnaces.
So, I just let my lead waste accumulate for several years, because I couldn't find the furnace I wanted. Then it hit me. I watched The Patriot, too. All I needed was a source of heat that could be safely sustained for an hour or so. In my neck of the woods, we call that a barbecue grill!
I'm starting the charcoal to reduce that pot of lead waste to useful ingots.
About the same time I had my epiphany, Edith gave me a large cast-iron pot she didn't want. If she hadn't, I could have bought one like it on eBay for $10-20. That and the grill was almost everything I needed to process the pellet waste I'd been saving. I did buy a cast-iron lead ladle ($13 with shipping) and a long-handled spoon ($2) to round out my lead-melting tools.
Yeah, but will it work?
Is a barbecue hot enough to melt lead? Well, mine certainly is! In fact, it only took 30 minutes to melt that 20 lbs. of lead waste and to cast shiny ingots from the lead. Before I get to that, though, a few safety tips.
Work outdoors, so the lead fumes are not an issue. Remember that lead is hot, so wear a long-sleeve shirt and eye protection. Do not allow a drop of water to enter the lead pot. If it does, there will be a small explosion and lead drops will fly everywhere. And finally, don't cook food on this grill after using it for this purpose. It's just not a wise thing to do, because the lead gets on every surface through the fumes. Better safe than sorry!
It took 10 minutes for the fire to become sufficiently hot for the lead to start melting. Once it did, the pile in the pot started to shrink. As the lead chunks melted, the air spaces between them disappeared and the pile naturally got smaller.
When I started, the pile in the pot was high.
The heat had been on about 10 minutes, and the lead on the bottom had liquified. In another 20 minutes, it will all be melted.
The area initially smelled like a barbecue, naturally enough. But after 10 minutes, I smelled the familiar odor of melting lead, which smells like melted candle wax. My grill allows me to raise and lower the charcoal fire, so I can control the heat. If you have a grill without that capability I recommend setting the pot directly on the charcoal. Just be prepared to move the pot with pliers if you do, because when the lead is gone you'll want to take it off the fire.
These are the tools I used. The ingot mold holds two one-pound ingots and two half-pound ingots. The spoon is for skimming the lead pot, the cast-iron ladle is for pouring lead into the mold and the large pliers are for handling the lead pot.
By 30 minutes, the lead was all melted and the considerable paper was all charred to ash. It formed a layer about a half-inch thick on top of the molten lead because it's lighter. The bullet jackets and steel BBs are also lighter, so they were mixed in this layer, too.
The junk on top of the lead is called dross. Here it forms a thick layer. A long-handled spoon is used to skim it off.
I skimmed the dirt, called dross, off the top of the lead. I had a cardboard box handy to contain it. While it is hot when it comes out of the pot, the heat goes away quickly after it's out, so the box doesn't catch on fire.
This is dross. It consists of charred paper, dirt, some molten lead and a bullet jacket.
Much of the dross has been removed and the molten lead can be seen. If there is a non-shiny gray scum on top, it is molten tin. You want to retain as much tin as you can, because it helps the lead fill a mold and is more expensive than lead.
When I got down to the melted lead I saw a gray scum on top. That's molten tin and it's very desirable to retain. Don't skim it off.
Once the lead was skimmed of dross, I started dipping out molten lead to fill the ingot mold. It produces two one-pound ingots and two half-pound ingots in a single pour.
The level of lead in the pot gets low, so I use the pliers to tip it up so the ladle can scoop the lead.
Fill the ingot mold, then dump out ingots like these. It takes about 20 seconds for the lead to completely harden in the mold.
The beauty of ingots that weigh either a pound or a half-pound is they can be added to a bullet alloy in exact amounts. So, these ingots are desirable, but they aren't absolutely necessary. I've used muffin pans and small pie tins in the past to mold my lead ingots. But these ingots are much easier to use later on. I got a total of about 18 lbs. of ingots from my waste lead.
Next I dumped about 40 lbs. of wheelweights into the pot and tried to melt them into more ingots. However, I met with an unexpected problem.
I filled the pot with about 40 lbs. of wheelweights.
Each wheelweight is attached to a steel clip that holds it to the wheel rim. Those clips conduct heat better than the lead and have great mass with a minimum of weight. If there were enough lead, they would float on top, but in this case they formed a honeycomb mass that rose as high as the molten lead. It was impossible to deal with them. I tried picking them out of the pot with pliers, but there were too many. It's also necessary to remember that antimony in the lead raises the melting point, and wheelweights have a lot of it. So, the fire has to be hotter. I tried to melt the wheelweights for two hours and all I succeeded in doing was burning up the last of my charcoal.
I solved the problem the next day by building a hotter fire with more charcoal and by adding another 20 lbs. of lead to the pot to get the level of the molten lead higher in the pot. Then the steel clips floated as they should and were easier to skim from the pot. The wheelweights yielded about 35 lbs. more lead, bringing the total for this exercise to over 50 lbs.
Now I have a pile of new ingots to add to my supply. The next step would be to use them to cast bullets. For that, I use an electric lead pot with much better temperature control.