Help! Problem with lead for bullet casting.

[Smokey Joe]

Casting along, using wheel weights we smelted earlier today. Nice clean ingots put into RCBS casting furnace. Molten lead running well, casting good bullets, when suddenly the lead starts to run slowly, then drip, then almost stop. Furnace set at 725° F. Tried lower and higher settings to no avail.

Wot the heck went wrong??? I now have a casting furnace half full of lead that won't run out the bottom.

Suggestions? Please?

[Selena]

Casting along, using wheel weights we smelted earlier today. Nice clean ingots put into RCBS casting furnace. Molten lead running well, casting good bullets, when suddenly the lead starts to run slowly, then drip, then almost stop. Furnace set at 725° F. Tried lower and higher settings to no avail.

Wot the heck went wrong??? I now have a casting furnace half full of lead that won't run out the bottom.

Suggestions? Please?

Sounds like you have a bit of dross stuck in the outlet. With the furnace set a full hundred + degrees over the melting point you have to expect a degree of oxidation. One thing to try is to find an old fashiony knob type automotive choke wire. Put the wire end into the spout and secure the assembly. Heat the charge and when the lead has melted push the knob in four of five times. That should clean it out.

[RecoilRob]

You might have gotten a zinc weight in your mix...in which case you are going to have problems. Probably going to have to remove all of what isn't working in there and replace with known good alloy.

Selena is rarely wrong (OK, I can't remember her EVER being wrong) so you might just have some dross clogging you up. But when you bulk melt wheel weights you've got to watch for floaters quickly and get them the hell out of the mix before they melt or you'll encounter the very thing you are getting now. Good luck!

[armoredman]

I have a skinny long nail and my Leatherman pliers next to me when I cast. When the dribbles begin, I grab the pliers and snag the nail, to work it up into the spout, rotate around and get whatever is clogging to move. Also will move the valve lever and the valve rod gets wiggled back and forth, CAREFULLY WITH HEAVY GLOVES, I hate being burned. It may take a few minutes, but eventually it will move again, and it also tells me to flux again.

[Smokey Joe]

We'll try the spout-cleaning techniques. I don't enjoy getting burned, either. Will be using welders' gloves and great care. I think I have devised a tool to get all the way up the spout.

Really, my furnace was running too hot?? Will try @ 625.

Tried VERY hard to not get any zinc WW's into the mix--dropped each and every one on concrete floor, rejected any that had any sort of ring to 'em. But I do respect Murphy's Law; one could have got by. There were many rejects.

And, BTW, just what is the horrid thing that will happen if I do get a bit of zinc in the mix? Have always heard that zinc is bad, but no one ever seems to say exactly what will go wrong.

Thank you much for the responses.

[Old Grump]

Lead melts at 600 degrees and zinc melts at 787. The fluxing helps the lead to re-oxidize and turn back into lead metal from the lead oxide that it was. Fluxing is not a magic elixir that will remove all molten impurities from the lead alloy. The carbon of the sawdust binds to aluminum calcium and zinc and helps get it out of the mix. Stand by for smoke, I hope you have really good ventilation in your smelting area.

Most common problems are calcium, aluminum and zinc. If you got it hot enough to melt zinc and it's now part of the alloy that batch of lead should be discarded or used for something besides bullets. If your bullets that you have poured are looking good then zinc is not your problem and you just have garbage on the bottom of your pot. Zinc changes the surface tension of lead and makes it impossible to completely fill a mold when you are casting. You alternative is to dump handfuls of sawdust into the pot and scoop out the dross, (I use an old fish scaler).

If you can scoop out most of the lead from the top of the pot and pour it back into an ingot mold, ( I use old muffin tins), and get the good lead out it should be easier to get to the gross dross on the bottom that is causing your problem. Don't do anymore super heating it only encourages impurities to bind with the lead and makes the lead oxidize. Only a guess but your problem may very well be lead oxide.

[Smokey Joe]

Old grump--NOW I understand the Zn problem! And I can tell you that that was not the problem, thank goodness. The bullets we were casting (back before the furnace nozzle choked) were filling the mould nicely.

Don't think I ever ran the furnace up to 787, tho' close, anyhow.

Now, garbage in the pot, THAT I got! Emptied out the furnace completely, right down to the bottom (took a while bailing, but finally! then dumped the last ingots' worth) and discovered an interesting collection of yellow-brown crud on the bottom and sides of the pot. Looks almost like sand. While I was at it I scraped all of that off & removed. Some ashy, burnt stuff, too. All gone now.

It's a newbie mistake on my part. I bought a used furnace, which had a layer of lead alloy in the bottom at purchase, so just took it on faith. Did NOT clean the pot before starting my own bullet casting career, and the thing worked fine for several sessions. But the crud caught up with me eventually.

Now, the problem is, that the crud is still in the hole around the rod that goes down to open & shut the nozzle. Can't get it out, not yet, anyhow. Can't get a tool up the nozzle all the way, either.

What I used for a nozzle tool is a bicycle spoke (sturdy steel wire, right diameter, bendable as needed) held in a vise-grip. Even hammering on that couldn't get it all the way up the nozzle. Even after heating the nozzle with a torch.

I think my next move is a call to RCBS Custserv, tomorrow.

Anyhow, thank you one & all for your help.

[RecoilRob]

Can you take the furnace apart? If so, when taken to bits you should be able to clean the orifice with a drill if necessary. I believe some are riveted/welded or otherwise impossible (more difficult at least) to disassemble so that might not be an option. I'm a dipper and haven't used one of those new fangled automatic furnaces.

[Selena]

Selena is rarely wrong (OK, I can't remember her EVER being wrong)

You forgot the red font.

[Smokey Joe]

Well, got the nozzle cleared, finally!

It only took 2 days of fooling around, plus the use of a dremel tool with a cone-shaped grinding head, lots more torch heating, more use of my bicycle-spoke poker, partially dismantling the furnace, and a scraper of my own design.

Got that done too late in the day to try a new batch of lead in furnace--will do that tomorrow. I will flux faithfully! I will not heat the lead hotter than 650°. I will scoop off the dross regularly.

Learnt my lesson. Just hope the cleaned-out nozzle works!

Will keep y'all informed.

And a hearty Hi-Yo-Thankyou, to all who gave advice.

[Smokey Joe]

Got bullets cast. Have been doing all the above in my garage, w/the big door open, for ventilations' sake. A little breeze does get in. Apparently that's enough to cool the pouring nozzle on the furnace.

So, when the furnace pour slows to drips--having fluxed, and using clean lead in clean pot--I turned on a propane torch and gave the nozzle a shot or 2. Nozzle responds by un-plugging and running great.

Cast up a nice mess of .452 semi-wadcutters.

Following day I set up my Lyman lube/resizer--it's the old model, and they say it doesn't fit on their heating pad, but I got it to fit anyhow--and sized the bullets to .451 and lubed with Orange Magic.

Worked slick.

Thank you one and all for all your helpful thoughts and advice!

[Old Grump]

Congratulations, sounds like you have the beast tamed. Suggestion, get a small fan and hang it overhead blowing out the door or out a vent or window and protect the furnace from getting an outside breeze blowing on it. You want the air flow blowing the fumes away from you and no cold air on the pot or it will have to work harder to maintain temperature.

[Selena]

Got bullets cast. Have been doing all the above in my garage, w/the big door open, for ventilations' sake. A little breeze does get in. Apparently that's enough to cool the pouring nozzle on the furnace.

So, when the furnace pour slows to drips--having fluxed, and using clean lead in clean pot--I turned on a propane torch and gave the nozzle a shot or 2. Nozzle responds by un-plugging and running great.

Cast up a nice mess of .452 semi-wadcutters.

Following day I set up my Lyman lube/resizer--it's the old model, and they say it doesn't fit on their heating pad, but I got it to fit anyhow--and sized the bullets to .451 and lubed with Orange Magic.

Worked slick.

Thank you one and all for all your helpful thoughts and advice!

I'm glad it all worked out for you. But beware, solving little problems like this is the first step to the downhill spiral that leads to being an OMB. The scraper of your own design is a warning sign. Just say no to obsessive machine building.

[Old Grump]

I'm glad it all worked out for you. But beware, solving little problems like this is the first step to the downhill spiral that leads to being an OMB. The scraper of your own design is a warning sign. Just say no to obsessive machine building.

What you talkin' bout woman, he is just gettin' a good start. No time to be discouraging the lad.

[Selena]

What you talkin' bout woman, he is just gettin' a good start. No time to be discouraging the lad.

I know how these things work...

It starts out realizing his lead pot can get up to a temp that will melt zinc. Then he wonders what else he can melt. And before you know it there is a forced draft oil burning foundry in the back yard with the casings of green sand molds all over the place and when his poor long suffering niece goes to use her very favorite aluminum saucepan she finds he has melted it, the screen door and the engine to the lawn mower to cast the faceplate for his new lathe. Lead pots are the gateway and OMB behaviors need be nipped in the bud before they start!!!

[Old Grump]

I know how these things work...

It starts out realizing his lead pot can get up to a temp that will melt zinc. Then he wonders what else he can melt. And before you know it there is a forced draft oil burning foundry in the back yard with the casings of green sand molds all over the place and when his poor long suffering niece goes to use her very favorite aluminum saucepan she finds he has melted it, the screen door and the engine to the lawn mower to cast the faceplate for his new lathe. Lead pots are the gateway and OMB behaviors need be nipped in the bud before they start!!!

Don't be silly, aluminum isn't much good for use as bullets and aluminum melting point is only 661 degrees. Her pots and pans will take more heat to melt because they are an alloy but still bad bullets. Now the lawnmower idea has me intrigued, I have some old 2 stroke engines laying around that would be more trouble than they are worth to get running again. Maybe we can make a mortar.....hmm, yeah some molders clay and a good form maker, I have the pneumatic tools to compress the mold into the desired hardness for pouring. Let me know when you are ready and I'll provide the motors for melt down and some of the tools we will need.

[Selena]

Don't be silly, aluminum isn't much good for use as bullets and aluminum melting point is only 661 degrees. Her pots and pans will take more heat to melt because they are an alloy but still bad bullets. Now the lawnmower idea has me intrigued, I have some old 2 stroke engines laying around that would be more trouble than they are worth to get running again. Maybe we can make a mortar.....hmm, yeah some molders clay and a good form maker, I have the pneumatic tools to compress the mold into the desired hardness for pouring. Let me know when you are ready and I'll provide the motors for melt down and some of the tools we will need.

Oh sure Old Grump, feeeeeed the nightmare! Aluminum is strong enough to make components of various machine tools you can build your mortar with. I don't know about molder's clay. The molds I was taught to build used fine grain "blow sand" formed wet then dried in a kiln. The only time I was trained with kaolin was in building crucibles the old OMB used to melt steel for casting. While I miss the OMB, I don't miss the sudden disappearance of various metal objects.

[Old Grump]

Oh sure Old Grump, feeeeeed the nightmare! Aluminum is strong enough to make components of various machine tools you can build your mortar with. I don't know about molder's clay. The molds I was taught to build used fine grain "blow sand" formed wet then dried in a kiln. The only time I was trained with kaolin was in building crucibles the old OMB used to melt steel for casting. While I miss the OMB, I don't miss the sudden disappearance of various metal objects.

You forget, I'm old, bentonite and oil, usually linseed as our binder. You youngsters use green sand and water. I didn't make the molds or pour, I was at the other end of the process of fixing what was broke in the foundry. You wouldn't believe how many things there are to break or how good at breaking them the line workers were. Air in the foundry was always blue because of the oil in the air and I finally had to quite because I had inhaled enough fine particles it was turning my lungs black and making me sick. Wasn't to bad on the floor where most people worked but a lot of the stuff I had to fix was up in the overhead and that is where I got tangled up with all the goodies.

[Selena]

I didn't make the molds or pour, I was at the other end of the process of fixing what was broke in the foundry. You wouldn't believe how many things there are to break or how good at breaking them the line workers were.

My uncle was old as well, he used green sand as you call it because there is a sand hill behind the house that was far less expensive than bentonite and oil that worked very well for him.

And I can imagine what all could break down in a foundry. Just the pumps and blowers would be a full time job to maintain in a serious enterprise. But his was not a production foundry, the largest furnace he had would only melt about 60 or 70 kilos of steel or cast iron and it was only used twice after I got to the farm. Just to give you an idea of the attitude, the old man often claimed it was possible to melt steel in a (plastic) five gallon bucket just to see if he could get some ...uh... foolish enough to bet money on it. (It is possible but 3/4 of the bucket volume is used for refractory material. )

[markshere2]

I have made several tens of thousand boolits from wheel weights.
I'm not a guru yet, but I've had very few issues.

I smelt WW in a different process than casting.

Propane turkey fryer and a cast iron dutch oven to hold the WW.

Smelt 'cool', just hot enough to melt the lead.

I have a coarse wire scoop to get the clips and zinc WW off that float on the top.

I have a scoop that has holes in it to get dirt & crud off the top of the liquid lead.

And a ladle to fill the ingot molds.

works for me............

[Old Grump]

I have an old fish scaler that I have been using for nearly 50 years to skim off the dross and solid debris from the pot. the teeth of the scaler were good for hooking things, scraping the pot and just enough scoop inside the scaler to gather up a good quantity of dross. Old tech but it works like a champ.