Need help casting over the head type decoy anchors

MIKE-SID

Active member

I need help casting over the head type decoy weights, I bought the Lil Mac mold # A-3100 shown on this page http://www.lilmacmolds.com/A-Series_Molds.html The problem is that The mold is not completely filling. Most of the time I'm getting a void on the bottom or sides. I don't have this problem making my 8 oz mushroom to 7 oz H weights. Do I need to add something to my lead pot? I'm using an electric Lee pot. Do I need to put something on my mold? I had to cast about 2-3 dozen in order to get 7 good weights. By that time the mold was too hot to cast well.
Thanks for the help.
 
Mike,

Invert your mold over a candle and smoke the cavity with a thick coating of soot. That'll help with flow. I try to keep my temps on a 10# Lee pot at 7 to 8. If you get it too hot you'll be inhaling the vaporized lead particles and that's not good for you...

George
 
George has a very good suggestion. I'd try that first and if that does not cure the problem then you may need a vent. This may sound off the wall and it may well be. To create a vent without altering your mold,
(A) get some ordinary aluminum cooking foil, the real cheap stuff (it will be thinner)
(B) cut a strip about a 1/4 inch wide and place it between the mold halves as shown, keeping it beyond the actual mold cavity.

The strip will provide a temporary air gap and yes I would expect some molten lead leakage. Obviously this is a temporary solution as I expect you would not want to mess with the foil and removing the lead flash leakage on every casting. If adding some venting cures the problem, then you can decide if you wish to alter the mold with an actual vent channel.





View attachment decoy mold revision.jpg
 
I have a custom machined anchor mold that I use to make "H" anchors. When first using it, I had the same problem. I found, the mold has to be hot first. The lead would start to cool before the cavity was filled up.

I now use an old Coleman gas stove to initially heat the lead in large quantities before pouring into my Lee smelter. While melting the lead, I also heat the mold on the other burner at the same time. Usually, as the lead is ready, the mold us hot enough to start pouring the anchors. Once it is, I can produce anchors as fast as I can melt the lead and pour them.

I've always been worried that I may melt my mold, but I just keep testing until it's hot enough.

Jon
 
I found that heating the mold is the only way to keep lead from setting up during the pour. It has to be real hot too. Setting mold on separate burner to heat it up is the trick. Once you get the right result on your pour you can crank them out as fast as you can pour.
 
Thanks for the ideas, I'll try the candle one first.
The Lil Mac website said my lead might be too hard too?? I am using a mix of wheel weights and other lead. I guess I can try some "clean" lead too
 
This was my first thought as well, the mold is not hot enough and the lead is setting up before it gets to the "bottom" of the mold.
As others suggested, make sure to heat your mold.
And work in a well ventilated space, with a fan pulling air away from the pot & mold & away from you. Wash your hands very well when you are done.
 
Heat mold, YES! DO NOT do anything involving lead indoors!!!!!! . After a few pours, and failures, the mold should be warm enough to accept the pour..
 

Thanks again. The mold heated up after a dozen failures. I think it eventually got too hot because when the mold was finally filling up, the weight would break in half when I opened the mold up.
I am casting in my basement in front of an exhaust fan I have mounted in the door in front of me. I usually wear a respirator too, but forgot last night. I'll put one on next time! I hope to try again Saturday after duck hunting, then Christmas tree hunting.
 
Mike, my experience is there is a sweet spot. You need a hot mold. When you get rolling, the hotter the mold, the longer you need to wait to open it. Buy yourself an IR thermometer, it will help in being consistent. I like to have several molds going to have a "steady" process.

I too heat the mold on a second burner, and then it may still take a couple pours to get to proper temp. Then I get a feel for how long to wait. I have an open face H weight mold, so I can see the color changes as the lead freezes. Remove too soon, it will be fudgy and break easily. Once you get a couple good pours, check the temp and record it. Or just trial and error each time. All the rejects get melted and used, nothing lost. My "lead" is all kinds of scrap too. Solder, lead, wheel weights, anything I get my hands on. As a result, my weights are harder, and initially shinny. A few hours in the water and they dull right up.

Bottom line: Voids, mold too cold or contaminated, castings break, likely removing too early.
 
MIKE-SID said:
Thanks again. The mold heated up after a dozen failures. I think it eventually got too hot because when the mold was finally filling up, the weight would break in half when I opened the mold up.
I am casting in my basement in front of an exhaust fan I have mounted in the door in front of me. I usually wear a respirator too, but forgot last night. I'll put one on next time! I hope to try again Saturday after duck hunting, then Christmas tree hunting.

I think the casting breaking is lead alloy (not pure lead) cooling slowly. Does the broken edge look like crystals (little crystals/granular)? I?ve only seen it in heavy aluminum molds where the lead cools slowly with wheel weight lead. The material cools slowly and forms crystals rather than typical non crystalline metal. If you can get that material to cast without breaking, the anchors will be very strong and not bend like pure lead. If you have pure lead keep adding it until you get a mix that works.
 
Thanks again guys, I'll get this to work.
Yes Dave like crystals. I thought that meant the mold was too hot? I'll wait longer before I open it up if that happens again.
 
Funny timing. Spent the week at some foundries who are working with us on a new program. I would say 100% your issue is the mold being cold. Cold mold leads to improper, or premature cooling of the metal being poured. On the work we were doing this week the molds were placed into an oven for a long time and a very high temp before the pour. The item the tech (guy who is dressed up like a baked potato) is holding is the mold and as you can see, it is glowing red/white hot.




View attachment Foundry2.jpg

Then the metal was poured. Great care was taken to ensure the metal remained at the exact correct pour temp and that the molds themselves were extremely hot. There is alos a very defined cooling process which I don't think you would be able to replicate nor would it be important. One thing for sure, do not take the molds apart until the lead has turned into a solid.


View attachment Foundry1.jpg

Very cool to watch all of this this past week. Very tough jobs working in a foundry.

Mark
 
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Wheel weights in NY since 2012 have been non-lead usually mostly tin as is most solder.

When casting sinkers I found that if there is alot of tin in the mix the pour is more difficult and the results crack more.

While tin is malleable, my experience is that it is also pours a more brittal product.
 
Fred Burkhardt said:
Wheel weights in NY since 2012 have been non-lead usually mostly tin as is most solder.

When casting sinkers I found that if there is alot of tin in the mix the pour is more difficult and the results crack more.

While tin is malleable, my experience is that it is also pours a more brittal product.

I tried again Sunday for a couple of hours!
I made 3 good ones, and a hundred half ones. I tried smoking, venting . AT one point the mold was so hot the roll pin from the hinge fell out.
I'm going to try pure lead next. If that doesn't work, I'll use the mold as an anchor [w00t]
 
When pouring sometimes the first couple are duds. Just pull them out and put back into pot and repeat until mold gets to its happy place.

With pure lead candling never hurts but a hot mold usually does the trick.

As long as you don't over heat the lead which is way beyond the melt point the potential exposure to lead fume should be minimal. A primary risk will come from your handling of the lead. Touch lead, eat sandwich, smoke a cig, take a drink and you can poison yourself.

It is always advisable to wear a properly filtered respirator (P100 is the standard) and to use gloves to minimize lead on your hands. Always wash your hands and faces once you are done and put what you were wearing in the wash.

Something that most don't think of is that you can easily poison your family or pets inadvertently. Don't pet your dog, or pick up a child or hug your wife until you are clean.
 
I took a look at that mold you are using and it has a lot of nooks and crannies. I believe you'll need some really good clean lead to make a pour with that intricate mold.

If you're ready to throw in the towel let me know and I might be interested in trying that mold myself. (more of a challenge than anything. lol) If I can get it to work I have a lot of lead and can pour you some weights.
 
I worked for a utility and wiped lead. We used stearine flux to clean and move lead. Looks like a candle, I coat the mold and drop some in the pot to clean lead. Smells bad, but lets the lead flow.
I heat the mold on the lead pot. Call the manufacturer for recommendations. What are you heating the lead in, plumbers pot or smaller? Smaller units probably aren't hot enough...
 
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