Muffin pan gas pockets???

[44fanatic]

When I pour my in a muffin pan, gas pockets form on the bottom and sides.

Care to fill me in on what is going on here. Curious not concerned.

[Bob J]

When I pour my in a muffin pan, gas pockets form on the bottom and sides.

Care to fill me in on what is going on here. Curious not concerned.

Have seen that with mine as well..... After a few casts they pretty much went away so thought it might be some sort of protective coating that got vaporized by my lead....

[Mk42gunner]

I always thought it was the teflon coating burning off. Stand upwind the first few times you use new muffin tins for ingots.


Robert

[bigboredad]

not sure what it is but when I set my muffin pan on wet rags the poor I don't get them. Without the wet rags to help cool down they show up again

[JesseCJC]

I wondered the same the other day, although it seems not to be a problem with slow pours

[chris in va]

Same with mine, I don't think it's the teflon. Something to do with thermodynamics I would think.

[cheese1566]

I haven't noticed the pockets in my mini-muffins, but they do make a "squeel" (more of a screech) when pouring the silver stream into them. Must be the thermo expansion taking place. After good and hot after a long time smelting, they stop "complaining".

[ANeat]

Ive only got them on teflon pans. Obviously something gassing out as the lead cools trapping bubbles. Any oil or other stuff on the pan would do the same thing.

[barefooter175]

Any recommendation on the "best" pans to use? Dies cast iron have the advantage?

[Mk42gunner]

Any recommendation on the "best" pans to use? Dies cast iron have the advantage?

I started with muffin tins, they work better the rustier they get (easier release). I tried cast iron ingot molds, didn't like them. I have since graduted to 1 1/2" angle iron for ingot molds; you can make them long enough to fit across you casting pot to preheat to get rid of any moisture in the ingot when casting. They will also self feed once you put one end into the melt while casting.

Angle iron ingots tend to stack well also.

Robert

[masscaster]

Hi all,
No matter what your using for ingot moulds do this(usually before you start using them):
1) get a little old motor oil, bacon fat, or even bearing grease (not lithium).
2) put a little on a rag and lightly coat the surface, all around in the ingot.
3) while getting setup to smelt, turn the burner on very low.
4) flip the mould(s) upside down and allow the oil, grease etc. to cook off.
5) using pliers (of course), flip back over onto whatever you use to set your ingot moulds on.
They'll cool quite abit while your doing your melt.
6) pour the lead slowly the first time or two, it may pop a little.
After that it's pour man pour!!
You can also do this with old and rusty ingot moulds, it'll re-season them, bringing them back to life. Of course the same can be done in a Wood Stove with somewhat better results, as they get smoked as well.
Jeff - a.k.a. masscaster

[Cowboy T]

I've got two muffin pans. One's got Teflon on it, the other doesn't.

The Teflon-coated muffin pan gives me bubbles on the bottom only (still good muffin ingots, though). The one without the Teflon gave me a smooth muffin bottom from the first time I used it. No prep work with either, just poured the lead into 'em as bought from the store.

[Rock]

Over 500 lbs of ingots have been produced by my tired old muffin pan, and it still surprises me with a bubble on the bottom of an ingot every now and then

[montana_charlie]

Any recommendation on the "best" pans to use? Dies cast iron have the advantage?

I prefer it...

[Dale53]

NOTE:
Teflon gassing off is highly toxic. I suggest NOT using tefflon coated ANYTHING for molten lead.

I have a number of regular ingot moulds (RCBS, Lyman, Lee, and Saeco). However, my favorites are my "home made" angle iron molds supplied by a good friend who is a professional welder:



FWIW
Dale53

[Hopalong]

About the muffin pan pockets--I get them too. I think that they come from vaporizing grease that had accumulated in the metal as a natural part of seasoning the pans. Eventually, all that stuff cooks out, and there is no more problem with the pockets. On the other hand, if you're using new muffin pans, I don't know--but it might be due to residual release compounds used in the manufacture of the tins. As you suggest, I don't think there is any danger in either case.

[leadman]

I have cast muffin pans and only noticed the bubbles when the humidity was was up or it had recently rained. I store my smelting gear in a metal shed so it is subject to weather changes.

My Lee aluminum ingot molds don't do this.

If the humidity has been low (Phoenix) I get no bubbles. I think the rust hold the moisture and it expands when hot lead is poured in.

[Thecyberguy]

I just acquired 80 pounds of lino and thought I would like to pour it into small ingots. I looked for a uncoated mini muffin tin. I bet we looked in 20 stores. Now a days all most all of them have some sort of coating.

I finally settled on one with a dark coating from Wally world for $5.

Before pouring the lino in for the first time , I threw it on my gas grill and closed the lid, set it on high and cooked the **** of it for 1/2 an hour. Temp got up over 500.

Let it cool down and poured the nicest, smoothest mini ingots you ever saw. They damn near jumped out of the pan when I tilted it up.

My son felt the need to weigh them on my new little digital scale. They were from 6.5 - 8 oz. Just right to use for a small batch of alloy, easy to melt and store.

Worked great for me. Have a good 'un, Guy