# Making a Lead Sinker Mold???



## TomS (Dec 15, 2017)

I have zero experience with casting metal but that hasn't deterred me from attempting to make a lead sinker mold.  And I must say it's not going well.  The finished  sinker/weight shape is 1/8" half round about 9/16" to 5/8" long.  The grooves in the mold are about 6-1/2" long, width is 1/8" and depth is 1/16".  The mold is preheated to 300 deg. F then the molten lead is poured.  The attached pictures show what's happening, or not, during the pour process.  I'm thinking I need to add a vent to the closed end of each groove but what do I know.  

This started out as a request from a friend for what I thought was a few dozen weights.  He's now telling me a relative of the inventor of the "No Name Lure" wants to relaunch the lure business and make thousands of these and sell them commercially.  Maybe a mold is not the way to go.  Possibly injection molding or extruding would be better.  I'm interested/anxious to hear what you all have to say.     

Thanks


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## ELHEAD (Dec 15, 2017)

Definitely not an expert, but have poured lots of jigs , sinkers and round balls for muzzleloader. Looks like mold is still too cold. Just my two cents.
Dave


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## owl (Dec 15, 2017)

Molds need to be vented too.  You may have too fine a finish between the halves.


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## Nogoingback (Dec 15, 2017)

I'm no expert either, but that mold looks like it need vents.  The air inside has no place to go, particularly with the long
skinny shape of your part.  If your finished parts are cut from the parts you're trying to pour, you might also consider making them shorter to start with.


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## Robert LaLonde (Dec 15, 2017)

Try dusting it with talcum powder and preheating the mold. 

Most mass produced lead castings are made in limited life heat vulcanized silicone spin cast molds.

Vents may help, but try the first tip above first.


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## kvt (Dec 15, 2017)

Have poured a few lead sinkers,  Disk, balls, and various others,  Looks like mold to cold, and by the end the lead had cooled to much.  With something that long and skinny you will have to keep the lead up to temp all the way down to the bottom of it.   If it starts getting cold before it gets to the bottom or to the last one you pour it will start looking like that.   Or at least that is my 2 cents on it.


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## Groundhog (Dec 15, 2017)

Bob La Londe said:


> Try dusting it with talcum powder and preheating the mold. Most mass produced lead castings are made in limited life heat vulcanized silicone spin cast molds. Vents may help, but try the first tip above first.



Bob's tip probably comes from experience and knowledge but I'll add this.
I make lead molds for a friend who makes bass jigs (or plugs or whatever). He coats both halves with soot from a burning candle. I'm not even sure why he does this. I have had to remake some molds when the channels were too narrow to allow the lead to flow quickly enough not to cool.


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## David S (Dec 15, 2017)

Adding the soot is the same that they do when pouring Babbitt bearings on shafts to keep it from sticking.

David


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## Robert LaLonde (Dec 15, 2017)

Soot (candle smoke in particular) has a loyal following almost like the worship of alchemy or something.  It works better than nothing.  Graphite spray works better.  Somebody will no doubt mention DropOut, but the graphite spray lock lubricant from your local box store works just as well.  There are limits to how narrow a lead stream you can pour down a narrow passage, but often talcum powder works when graphite or candle smoke does not.  

Narrow lead clearances, and fine details are my nemesis in custom molds.  Talcum powder is usually my first fix.  Once in a while I find one that graphite spray works better.


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## Tozguy (Dec 15, 2017)

It seems like you are trying to cast wire, not how I would do it. Why not cast a shorter fatter slug then roll it to finished size? Check out bullet holding stuff from Lee Precision for ideas.


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## derf (Dec 15, 2017)

Why not just use solid core solder?


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## RJSakowski (Dec 16, 2017)

I cast a variety of lead jigs and weights. Off hand, I would say that temperature is the culprit. 

I use commercial diecast molds that have material removed from the outside to reduce loss of heat.  When I pour, I will fill the outside cavities with the molten lead several times before attempting to pout the mold.  A higher melt temperature will help as well,  Also, fluxing the lead and removing dross prior to pouring.  I have seen but do not use some pouring ladles that have a gate at the bottom to prevent dross from entering the mold. 

If I were looking at mass production, I would redesign the mold for faster openng and closing. My molds are all hinged and I use a clip to hold them closed while pouring.  To clear a mold, I pop the clip, open the mold and give it a light tap to discharge the castings.  I would also make the reservoir at the top of each cavity bigger.  I milled my molds out to make a common trough so I dont have to hesitate when moving from one cavity to the next.

As others have pointed out, you may need to add a vent to each cavity.  It won't take much; a scratch at the bottom of each cavity would do it


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## juiceclone (Dec 16, 2017)

long time since I made sinkers, but lead is pretty thick molten and the air in those molds has to come out somewhere.
think I would cut a large connecting passageway at the bottom and see if then works ok except for the last one :>)


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## TomS (Dec 16, 2017)

Thanks everyone for your ideas.  I now have something to run with.


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## benmychree (Apr 21, 2018)

It would seem that if large quantities are contemplated, a lead extrusion would make more sense than trying to cast them individually.


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## TomS (Apr 21, 2018)

benmychree said:


> It would seem that if large quantities are contemplated, a lead extrusion would make more sense than trying to cast them individually.



You are correct and that's what my client did.  He was able to find an extrusion with the desired cross section and now all he has to do is cut the lead sinkers to length.


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## Rob (Apr 22, 2018)

As has been mentioned you have 2 issues with the mold.  On bullet molds they have small vent lines running across the face of the mold.  If you go here and look at the face of the mold you can see the vent lines.  https://www.lymanproducts.com/brands/lyman/bullet-casting/bullet-moulds/black-powder-moulds.html.  The other issue that has been mentioned is that the mold is too cold.  When casting bullets it is a fine line between having the mold too hot and not hot enough.


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## Old Mud (Apr 22, 2018)

You could get solid solder that size and cut to length.


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## Charles Spencer (Apr 22, 2018)

Well, I haven't made sinkers or anything but I have cast hundreds of toy soldiers.  I don't think you are going to be able to cast lead down that narrow channel with just a gravity feed.  If it's not absolutely essential that the long narrow part be lead, I'd suggest using wire of an appropriate size, flattening the end that goes into the cone, and casting the lead on it. 

If you must cast the long narrow part then I agree that you would need vents.  Also, if you use a mixture of 80% lead and 20% tin by weight the metal will stay molten longer.  And lubricate the mold with talcum powder.  Putting plywood backing boards on the outside of the mold would help it to stay warm longer.

Some of my soldiers.  The gun crew figures are 40 mm tall and the grenadiers are 25 mm.


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## tq60 (Apr 22, 2018)

Just saw on TV mysteries of abandoned a tall brick structure used to make musket balls by dropping molten lead...200 feet.

Different approach.

Make a funnel that would allow pouring lead and output side is working wire size.

If placed over some type of oil for coolant then the lead would solidify while in shape of wire.

No clue if it would work.

Using a large soldering iron to keep funnel hot would be needed.

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## Old Mud (Apr 23, 2018)

tq60 said:


> Just saw on TV mysteries of abandoned a tall brick structure used to make musket balls by dropping molten lead...200 feet.
> 
> Different approach.
> 
> ...





  That's the way they use to make lead shot for shot guns, They called it drop shot.  Nice Army you have !!.


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## BGHansen (Apr 23, 2018)

Might be old news as the OP was in December, 2017.  Second the comments above about a vent and mold temperature.  I've cast a lot of lead, but it was in silicon molds (www.micromark.com for the 1-1 silicone mold material). 

You may try a higher temp on the lead or as suggested above mix tin with your lead.  Lead melts at around 620 F, Tin around 450.  Mix the two in a ratio of 1/3 lead, 2/3 tin and the mixture melts at around 360 F.  Problem you have is the metal mold is a heat sink and is sucking the heat out of the lead.  That's why a silicon mold works pretty well for filling, acts as an insulator and holds the heat in.

You may also try preheating the mold with a propane torch, check the temp with a non-contact thermometer.

Bruce


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## Charles Spencer (Apr 23, 2018)

I agree with Bruce that silicon makes better molds.  I tried to keep the tin in the alloy at the lowest level possible because it cost me thirty times as much as the lead did.  I melted the two together in a small cast iron frying pan and cast ingots in mini muffin tins.


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## Old Mud (Apr 23, 2018)

You can also use old wheel weights to get some tin in your alloy. If you don't mind smelting them out beforehand and dealing with the crap.


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## jdedmon91 (Apr 25, 2018)

This’s is a old thread. Growing up Dad poured a lot of jig heads and sinkers. Most molds we used was made out of cast aluminum so they heated up quickly in the first pour. It appears these molds were made out of steel so get them warm enough is a challenge. Then yes there needs a vent, or remake the mold to pour the thin to the large end. 


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## Silverbullet (Apr 25, 2018)

His real problem , the mold isn't hot enough to allow the lead to spread . Venting would help but most two piece molds allow plenty . I'd run a torch over the mold while pouring heating from the bottom up. Your mold is very well made it will work keep trying till the heats correct once it's hot it should be pour wait a second open dump and repour.


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