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With high hopes I set down to cast for the 30carbine for the first time. Using wheel weights I was going to cast a number of bullets to be heat treated later. Cleaned some of my wheel weights and picked through them after drying and threw them into the pot. Really thought I had 'em picked out. After a couple of pours to test, my pot just started dripping. Thought I had seperated any that contained Zinc but I was wrong. After filling the molds the bullets came out looking like some chewed up bubble gum that someone had spit out. Not only did it screw up my casting session but I think my pot is shot. I have an old Lee 4lb. pot with the spout and my spout is complety plugged. I empitied the pot, cleaned it and tried to mix more weights, that I carefully cleaned and sorted to try to remove the Zinc. Cranked the heat all the way up but to no avail. The spout is still completly plugged and will not pour. Will break it all down and clean and try a slightly oversized bit with a drill to remove any Zinc from the spout but the spout doesn't seem to be removeable. And the drain hole in the bottom of the pot is very hard to clean. That may be my main problem now. Haven't figured out a way to do that yet. Well, if nothing else ,I may be able to use it for ingots, if I can get all the Zinc out, and will just have to buy a 10lb. pot for casting as I don't think Lee sells the 4lb. anymore. May just have to trash this one as I don't know if I can remove all traces of Zinc. Bummer:(
 

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Your post is not making a lot of sense to me. Not one word about fluxing, for one thing.

You do not need to wash off wheelweights before melting them down; in fact don't, so that you don't run a risk of dropping a wet one into a pot full of hot lead. All of the grease, dirt, paint and road tar will cook off and pop up to the top

Get a common stainless steel tablespoon from your kitchen drawer and use it to stir the pot and scrape the sides. You want to get the dross (which is what I suspect your problem with "dripping" is) off the sides and out of the spout area and up to the top where you can skim it off.

You should really consider doing your metal processing in two steps: In the summer (when you can work in an open garage) melt down the wheelweights. Use your spoon to keep stirring the pot after the weights melt down. The spoon is perfect for scooping out the steel clips and any crud which floats to the top of the melt. Have an old steel coffee can or similar receptacle handy to put the crap in. Keep a box of kitchen matches handy - if the smoke gets too thick, often you can light it and it will burn, keeping your immediate vicinity less smoky.

Flux your wheelweight metal well and then pour into ingot molds. When the ingots are cooled enough to handle, you can take a lettering set and stamp them with "WW" (to identify as straight wheel weight metal).

One advantage of drawing the pot completely down is you get to inspect the sides and the spout area for dross buildup. When hot, this dross has no mechanical strength and can be easily removed.

Bullet casting should be a separate session. You start with a clean pot and clean ingots of wheelweight metal. Melt them down and flux well.

If you are using one of Lyman's steel bullet molds, do not expect perfect throws until your mold is up to temperature. Just keep casting bullets and returning them to the pot until your mold heats up and starts throwing perfect bullets. Never put grease in your mold cavity, that will give you problems.

I use an old Lyman MoldMaster XX pot; a 20-pound pot. I have had the same tablespoon and the same old coffee can for 30 years. Never a problem.
 

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Yes zinc can really screw up a good casting alloy, however all is not lost....
Zinc can be removed from a lead alloy by doing the following:

Run your pot upto about 770 degs or more, and stir. Now stir again.
Flux your pot with a teaspoon of powered Talc, ie unsented baby powder. (do this outside)
Turn the pot down, and let the temp drop down to 600 deg and flux again.
All / most of the zinc should separate from the Lead and float to the surface and can be skimmed off.

Depending on the zinc/Lead mix and size of your pot, you may have to do this more than once.

Also to fix a dripping Lee bottom pour pot: (while wearing heavy leather gloves, proper eye protection, etc)

Use a uncoated finishing nail held in a pair of needle nose pliers, with pot hot enough to pour and the pot handle up as far as it will go, poke the nail point first into the openning of the spout. Twist it around. As you pull it out, you should get a full steady steam of Alloy. (besure to have something under it to catch the flow)

Let the Pot handle drop down, and with a flat blade screwdriver, twist the post back and forth, as far as it will go in each direction. (there is a slot at the top of the post for this) Now pull the post back up again as far as it will go, this will allow any trapped dross that is under the post to free itself and float to the surface or exit out the bottom. If needed, poke your nail into the bottom of the pour spout again to dislodge any remaining dross / crud.

Also jimlay makes some good points about fluxing and allowing your molds to reach working temp. Also make sure to degrease your molds before use, or you will get bad castings.

-George
 

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Discussion Starter · #4 ·
Your post is not making a lot of sense to me. Not one word about fluxing, for one thing.

You do not need to wash off wheelweights before melting them down; in fact don't, so that you don't run a risk of dropping a wet one into a pot full of hot lead. All of the grease, dirt, paint and road tar will cook off and pop up to the top

Get a common stainless steel tablespoon from your kitchen drawer and use it to stir the pot and scrape the sides. You want to get the dross (which is what I suspect your problem with "dripping" is) off the sides and out of the spout area and up to the top where you can skim it off.

You should really consider doing your metal processing in two steps: In the summer (when you can work in an open garage) melt down the wheelweights. Use your spoon to keep stirring the pot after the weights melt down. The spoon is perfect for scooping out the steel clips and any crud which floats to the top of the melt. Have an old steel coffee can or similar receptacle handy to put the crap in. Keep a box of kitchen matches handy - if the smoke gets too thick, often you can light it and it will burn, keeping your immediate vicinity less smoky.

Flux your wheelweight metal well and then pour into ingot molds. When the ingots are cooled enough to handle, you can take a lettering set and stamp them with "WW" (to identify as straight wheel weight metal).

One advantage of drawing the pot completely down is you get to inspect the sides and the spout area for dross buildup. When hot, this dross has no mechanical strength and can be easily removed.

Bullet casting should be a separate session. You start with a clean pot and clean ingots of wheelweight metal. Melt them down and flux well.

If you are using one of Lyman's steel bullet molds, do not expect perfect throws until your mold is up to temperature. Just keep casting bullets and returning them to the pot until your mold heats up and starts throwing perfect bullets. Never put grease in your mold cavity, that will give you problems.

I use an old Lyman MoldMaster XX pot; a 20-pound pot. I have had the same tablespoon and the same old coffee can for 30 years. Never a problem.
I am sorry. Maybe I did not give enough info to clarify. I did flux the alloy with MARVELUX FLUX and stirred the alloy for quite a period of time to mix. Started to pour into an ingot mold to see how it was pouring and then heated up my Lee 2 cavity aluminum mold by setting it on top of the pot for several minutes. Aluminum heats up much quicker than steel. Started to pour into my Lee 2 cavity molds. The alloy started to just drip out and would not fill the mold properly. Don't know if you have ever had any experience with zinc in a lead alloy but apperantly I did not sort my wheel weights well enough and threw in a several that contained zinc. The only reason I cleaned the weights was because they were dirty and wanted to make sure I could tell them apart. Not because I didn't feel I could not flux the dross off. I also blowed dried the weights with a hair dryer on high and made sure I got them really hot to dry off any water that may be left in the crease of the clip and weight before I threw them into the pot. Let them sit for over fifteen minutes to make sure there was no water on them. I know not to throw wet weights into the pot. I have cast many 8mm bullets with pure lead mixed with linotype before and am not altogether new to casting just new to casting with wheel weights. Some of the newer weights contain zinc which can totally screw up your day and if you are not careful in sorting them out, you can get into trouble. As is what happened to me. Perhaps all of the wheel weights you have used to cast have been zinc free. Wish I could find a batch like that.
After I dumped my pot and scraped the sides and filled it with more weights that I was sure contained no zinc, my spout was still dripping, not flowing. I used a dental pick and stuck it up the spout. It flowed for a few seconds and became clogged again. Could not get it to flow freely again. Dumped the pot again and let it cool. When looking into the bottom there was a bunch of zinc just balled up in the bottom of the pot. I had to scrape it out even after heating it up again. Zinc has a much higher melting temperature than lead and turning my pot to the max would not completly melt it. And I let it set for a long time to try and melt it and clear it but it made no difference. It's not dross. It's zinc. My spout would not flow freely again.
 

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Discussion Starter · #5 ·
Yes zinc can really screw up a good casting alloy, however all is not lost....
Zinc can be removed from a lead alloy by doing the following:

Run your pot upto about 770 degs or more, and stir. Now stir again.
Flux your pot with a teaspoon of powered Talc, ie unsented baby powder. (do this outside)
Turn the pot down, and let the temp drop down to 600 deg and flux again.
All / most of the zinc should separate from the Lead and float to the surface and can be skimmed off.

Depending on the zinc/Lead mix and size of your pot, you may have to do this more than once.

Also to fix a dripping Lee bottom pour pot: (while wearing heavy leather gloves, proper eye protection, etc)

Use a uncoated finishing nail held in a pair of needle nose pliers, with pot hot enough to pour and the pot handle up as far as it will go, poke the nail point first into the openning of the spout. Twist it around. As you pull it out, you should get a full steady steam of Alloy. (besure to have something under it to catch the flow)

Let the Pot handle drop down, and with a flat blade screwdriver, twist the post back and forth, as far as it will go in each direction. (there is a slot at the top of the post for this) Now pull the post back up again as far as it will go, this will allow any trapped dross that is under the post to free itself and float to the surface or exit out the bottom. If needed, poke your nail into the bottom of the pour spout again to dislodge any remaining dross / crud.

Also jimlay makes some good points about fluxing and allowing your molds to reach working temp. Also make sure to degrease your molds before use, or you will get bad castings.

-George
Thanks for the info about talc. Never would have thought of that and will give it a try but don't know if my pot goes that high in temperature. I'm sure it should. No idea of the temperature range of the old Lee 4lb. pot. I use MARVELUX FLUX. By the way, I do all of my casting of ingots and bullets outside. Never in my home or shed.
I use Lee molds which are aluminum and heat quickly. Once I get my alloy to melt and it pours freely I set the mold over the top of the pot for several minutes to heat up before I begin to cast. Aluminum heats up much quicker than steel and I can usually get good bullets with the first pour.
After the spout started to drip, now I mean while trying to pour with the handle up not just sitting there idle, I used a dental pick to clear it. It did for awhile and then it just started to drip again and became clogged again. All the while with the handle up. I guess as the zinc passed through the spout it cooled and clogged it. I have cast many 8mm bullets using pure lead mixed with linotype and have problems with dross causing the spout to drip. Know how to screw the post back and forth but this is not the problem. MeThinks I threw in more weights with zinc than lead. Didn't even want one in there. The reason I cleaned them was to tell them apart because all the weights I have are very dirty and was picked up off the ground in a yard where someone dumped them. They are all full of mud, grass and weeds. I guess I missed. May never use wheel weights again unless I can find a sure way of seperating them from each other. Don't want to go through this again.:(
 

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Your last post does indeed clarify, and I hope I did not come across as insufferably snotty - if so, my apologies. Well, I am snotty some of the time, but I did not mean to be in this case.:rolleyes:

I have not had a zinc problem. Many years ago, I lucked into the Mother Lode of wheel weights; got them by the overflowing 5-gallon pails full. Gorgeous, genuine lead-alloy wheel weights with nary an "off" type in the whole pile.

I ran most of the wheel weights through the process I described already and ended up with hundreds of ingots of pot-ready WW metal. Look at my photos of gun room/reloading bench elsewhere and you'll see them, down on the deck under the bookcase.

I flux with old candle stubs; they do a fine job, and they are free.

I too have a slew of the Lee aluminum molds, and agree that they simplify life a lot. Most of my molds, however are Lyman steel molds - some of them are older than I am, (and I'm 62).

You have more experience in dealing with zinc, and it would be a service to others if you would let us know what works when dealing with it. For starters, are the zinc-bearing wheelweights easy to differentiate from the traditional lead alloy ones?

(and this is directed to gfisher): Can you explain how the talc works in the procedure you described?
 

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I am by no means a chemist, but this was how it was explained to me several years back.

Talc is magnesium silicate, and magnesium is one of the few elements that zinc will bond with even thou the melting points are differant. So as I understand it, when you flux with the Talc, it bonds with the zinc, which is in Suspension in the lead, it (the zinc) does not bond with the lead, it simply melts and is mixed with it. Example, if Lead were Blue, and Zinc yellow, when melted togeather a mixture would turn green. A Suspension would remain a swirl of Blue and yellow. The Talc bonds to the Zinc, and allows it to be sperated from the lead. Since zinc has a higher melting point than lead, as you drop the temp of the pot, the zinc, now bonded to the Magnesium, floats to the surface in globs of grayish powder that can be skimmed off. Sorry if that does not fully explain it, like I said, I am not a chemist, I was in the same position a few years back as the original poster, was told about this, tried it and it worked.....

-George
 

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Discussion Starter · #9 · (Edited)
Your last post does indeed clarify, and I hope I did not come across as insufferably snotty - if so, my apologies. Well, I am snotty some of the time, but I did not mean to be in this case.:rolleyes:

I have not had a zinc problem. Many years ago, I lucked into the Mother Lode of wheel weights; got them by the overflowing 5-gallon pails full. Gorgeous, genuine lead-alloy wheel weights with nary an "off" type in the whole pile.

I ran most of the wheel weights through the process I described already and ended up with hundreds of ingots of pot-ready WW metal. Look at my photos of gun room/reloading bench elsewhere and you'll see them, down on the deck under the bookcase.

I flux with old candle stubs; they do a fine job, and they are free.

I too have a slew of the Lee aluminum molds, and agree that they simplify life a lot. Most of my molds, however are Lyman steel molds - some of them are older than I am, (and I'm 62).

You have more experience in dealing with zinc, and it would be a service to others if you would let us know what works when dealing with it. For starters, are the zinc-bearing wheelweights easy to differentiate from the traditional lead alloy ones?

(and this is directed to gfisher): Can you explain how the talc works in the procedure you described?
No worries jimlay. Perhaps I was a little sensitive and still peeved about messing up my pot. I will try gfishers method and hope it works. I have some talc powder in house but scented so I will look for the unscented type on my next trip to WallyWorld.
As far as zinc in your alloy I am no expert and, this is my first practical experience with it. I will give you a couple of quotes from my Lee Second Edition and Lyman Cast Bullet Handbook.
Lee: Avoid shiny wheel weights as they may contain zinc. (Hence the cleaning process also and the only way I know of to tell them apart. Of course some may contain more than others and appear brighter than others. From now on when in doubt. I will through them out. If someone knows of another way please post.) Continuing: Zinc is bad! One part of zinc in 10,000 parts of lead alloy will ruin it's castability.
Lyman: At 850degrees F, which is within the normal range of bullet casting temperatures, lead will dissolve a little over 2% zinc. If more zinc is added, an immiscible melt is formed and a puddle of the lower density zinc liquid will form on the surface of the molten lead, and no amount of stirring or fluxing will make it disappear. (and this tells me my pot should get plenty hot enough to try the method gfisher mentioned)
I did not fill my pot and only threw in several weights as I only wanted to cast around twenty bullets to heat treat and test for added hardness. I can only assume there was to high of a zinc content in the weights I threw in. And my own theory is that since lead may dissolve about 2% zinc, once you start pouring, the zinc, because of it's lower density, may cool faster, which causes the mold not to fill up completly and causes the alloy to start to ball up. Also which caused my spout to clog. And of course the higher content of zinc, the greater the problem. Will let you and gfisher know how the pot cleaning turns out. Want to continue casting as soon as possible.
Also, viewed your handloading setup and it is very nice.:)
 
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