New member saying hello and question on pouring lead

[Grumpy 232]

Hello. Long time fisherman, I've been getting into pouring cannon balls. Problem I'm having is shrinkage. Once it cools down to be able to open it, about a minute, the main part of the ball shrinks down, and at times breaks away from the gate area. Is it the mold? Temp of the lead? ( which I don't suspect). I've read tipping the mold helps, I've even turned it upside down when cool enough. I've tried waiting longer, doesn't seem to help. Thanks, Dave

[Ogajiga]

Sounds like you're describing incomplete fill out of the mold cavity when the inlet gate hardens prematurely and restricts melt flow?

[Kasilofchrisn]

Got any pictures of this problem?

What size cannon balls are you making?

I make them in every size from 1/2 ounce all the way up to 3+ pounds.

From what I read It sounds like your mold filled out all the way but as its cooling the sprue brakes off from the main sinker?

If this is the case just file the area clean and use it.

Are You using pure lead or an alloy of some sort?

I take it you're preheating your mold and you're fluxing really well before casting?

Tipping Only helps if you're mold isn't filling out completely.

But once the cavity is filled, tipping will not do anything.

 

 

Edited December 9, 2023 by Kasilofchrisn

[Kasilofchrisn]

Thinking about this overnight and it occurred to me that you may be talking about denting?

Were you pull Your sinker out and it has a dent in it.

If that is the case it is because your mold has gotten too hot.

Cool down your mold using a damp sponge or a heat sink of some kind or give it some time to cool off.

I used to get denting when I was making a really big casting I such as downrigger weights.

If I cool the mold down in between each casting the denting goes away.

 

[Arne]

Dont wind up with any moisture on or in it when you go to pour.. The stuff will come out a lot faster than it pours in.  Be safe. Arne.

[Grumpy 232]

I think there might be something to the mold being too hot. Doesn't do it cold, pics coming. 

[Grumpy 232]

16oz

[Kasilofchrisn]

OK so that is what I initially thought.

Your mold definetly filled out all the way.

If your not already doing so Flux your lead well before casting and/or try some different fluxes.

In all honesty I would file that area smooth and use those sinkers.

You were going to cut the sprue off anyway so no harm was really done.

 

[Ogajiga]

Is it possible to cool down a hot Do-it mold with water?  I have a brass single cavity on pliers 1/4 oz jig head mold that quickly gets too hot to release castings that I carefully squirt with cool water using a rubber bulb syringe.  Most of the water will evaporate & I swab out the cavity & gate with a paper towel to make sure no moisture remains.

[Kasilofchrisn]

2 hours ago, Ogajiga said:

Is it possible to cool down a hot Do-it mold with water?  I have a brass single cavity on pliers 1/4 oz jig head mold that quickly gets too hot to release castings that I carefully squirt with cool water using a rubber bulb syringe.  Most of the water will evaporate & I swab out the cavity & gate with a paper towel to make sure no moisture remains.

Do not squirt your mold with water.

Place a wet sponge next to your casting pot.

Set your hot closed mold on the sponge for a few seconds to cool it off.

Wet the sponge as needed.

Here's a video showing this technique for bullet casting. But, the same technique can be applied to jig and sinker molds.

 

Edited December 22, 2023 by Kasilofchrisn

[Ogajiga]

Sponge is a good idea, thank you.

[Tiderunner]

Is it me, or is the sprue separated from the cannonball? If so, that can be a few things. Starting with mold, and lead being too hot. Or pouring from the end of the melting pot and getting slag and other crud in your finished ball.

And lastly, poor quality lead can cause that as well Or again the quality of the lead drops off because as you use the lead to pour, the more crud is in it. You've poured off most of the clean stuff.

This happens to me a lot when pouring large (4oz-16oz) bank sinkers. Especially when the mold gets hot. Hot enough to melt the paint on Do-It handles. I just melt more clean lead to the pot as I pour. No matter how many times you flux, there is always some crud left behind.