Voids in ingots

[Mattog22]

Just melted down my first batch of WW tonight. I used the turkey fryer and a Dutch oven. I think the temp was about 600 degrees. I kept melting small amounts of WW till I had a decent amount in the pot. I kept skimming the clips, zinc, and steel WW off as I went. I bought 2 new mini muffin tins and smoked them with a candle. I used a small amount of the candle wax to flux and then ladle poured lead into the muffin tins. I only had time to fill each tin once before I turned off the fire. They came out of the tins easily but they had voids on them that looked like bubbles. I know I was going a bit slow and my pan was a little ways from the pot. Is this from the lead cooling too much by the time I got it to the pan, pouring too slow, or because it was the first time anything was poured into those pans? I don't mind voids in my ingots but I would like to know the cause since I don't want voids in my bullets. I did a search but didn't find anything about voids in ingots.
Thanks,

Matt

[AZ-Stew]

May be air trapped under alloy that was in the process of going from liquid to solid, depending on how quickly you poured it. Bubbles happen.

Don't worry about it. When you cast, you won't have air as the enclosure for the top of your casting. It will be the sprue plate on top, and as long as you pour a generous sprue puddle on top of the plate, then leave plenty of time for the alloy to cool, shrink and draw alloy from the puddle into the mould, you won't have boolit base voids.

Contact me if you have questions.

Regards,

Stew

[Mattog22]

Thanks AZ-Stew, just to clarify the bubble voids were on the parts where the lead was contacting the pan, the top where it was exposed to air had no voids. Either way it sounds like I won't have problems when I cast, I guess Ill find out!

[AZ-Stew]

Once you get the mould hot you should not have any problems.

Be sure to get the mould CLEAN before casting. There are many routines for cleaning a mould, but the most common is to put it under a stream of hot water from the faucet, squeeze a bit of dishwashing liquid soap onto the mould and then scrub the HELL out of it with a tooth brush. Afterward, rinse the mould under the stream from the faucet, followed by a THOROUGH drying with an air compressor hose or a long stretch in the sun. Make ABSOLUTELY sure it's dry before you cast with it.

Regards,

Stew

[lwknight]

You either got some wax/oil in the tins or you did not burn off the paint before using them.
Put the tins on the burner and cook them but good to red hot before using then for the first time and your bubbles will go away.
Only required on new pans that have not ever been burned out.

[mooman76]

You said you only had time to fill them once. That is probably it as when cold you don't get good fill out. If you had done another round you would have seen better fill out and less voids.

[44fanatic]

Probably the coating on the pan cooking off. I have a couple of muffin pans that still create "bubbles". The more you use them, the less it happens.

In my quest for the perfect ingot, someone had reccomended putting wet towels under the pan and pouring slowly...resulted in smaller bubbles.

Dosnt affect anything.

[fredj338]

In my quest for the perfect ingot, someone had reccomended putting wet towels under the pan and pouring slowly...resulted in smaller bubbles.
Dosnt affect anything.
Exactly, so why does it matter? You are pouring into a large open top mold. A bullet mold is way diff. Still, you can & will get occasional internal voids in your bullet casting. They will be found if you weigh each bullet. Does it matter? Sure, if ultimate accuracy is the goal, then any internal void will throw the bullet off it's line as it leaves the bbl. If you just want plinking bullets, probably not an issue. For match or hunting, I weigh all my bullets to check for internal voids.

[lwknight]

No one wants their friends to see ugly ingots.
I remelted my bubbly ingots and repoured after burning off the paint on the mold.

[Mattog22]

Thanks guys, I thought I may have done something wrong. Sounds like I'm on the right track so Ill see how my bullets turn out. I don't really care about ugly ingots, they all melt the same! Didn't realize people don't like talking about their ugly ingots!

[oneokie]

I use different sized drink cans for some of my alloys. All those ingots look like they have bad acne.

[Mattog22]

Bad acne is about the right description. Think I might make more tonight if it's not raining.

[geargnasher]

No one wants their friends to see ugly ingots.
I remelted my bubbly ingots and repoured after burning off the paint on the mold.

I thought I was the only one who would waste propane to remelt ugly, but clean, ingots. I even remelt purchased ingots and pour them in my own moulds.

Anyone else here attending help group sessions? :veryconfu

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