Casting question

[Maillemaker]

A speck or pindrop of water will cause an hydrogen explosion splattering molten lead everywhere.

I don't think hydrogen has anything to do with it, other than being part of what water is made up of.

The water is flashing into steam.

Steve

[jonk]

Absolutely the use of protective clothing is good advice for anyone!

The question of ventilation and what is enough... well, you often hear folks talking about 'lead fumes.' That part of it is bunk, at least if you're using an electric melter. They (by design) don't get hot enough to vaporize lead. If you're melting over some other fire source, well, it could get hot enough I guess. But if you're vaporizing lead you are going to need a lot more than being outside to mitigate it. What you do want the ventilation for is that a lot of lead is going to have some contaminants on it. Anything from oil to dirt to whatever. When that heats up it gives off (often a lot of) smoke, and that stuff can't be safe to breathe in. I always took it to mean "do it outside" or "do it near a window with a good exhaust fan pulling the stuff out." Besides... doing it in a basement, making a lot of stinky smoke, is a good way to have your wife/mother/girlfriend/sister/any other female in your life rightly rip you a new one. Where I think that material safety IS a good idea is when handling the cold lead. I've seen lead sheet especially with it's large surface area that left a dull lead colored residue on my hands. Lead oxide does wipe off and if you don't wear gloves or scrub your hands quite well, you can get some in your system that way.

The water thing. Yes, absolutely true, moisture and molten lead don't mix. But a little water on top of the melt does... nothing. I started casting long before there were internet forums about this sort of thing, and in my ignorance, when done casting for the day (using a propane torch and ladle) I would gently pour some water on top of the molten lead to harden it faster. Nothing happened, other than the water quickly boiled away. For water to create an issue, you have to get it UNDER the melt. The most likely way someone would do that is with putting a wet or even cold, damp ladle or ingot into a hot molten pot, as just that much surface humidity can cause issue. Or tossing range scrap into a hot pot; inside that minie base is mud, that has enough wetness in it to cause big problems. But to think a single drop of sweat falling from your nose into the pot will cause the tinsel fairy to show up just isn't true. Try to avoid it "just in case" but I'm just saying. It does however, have nothing to do with hydrogen or oxygen, just the rapid expansion of water due to steam formation.

[B P Shooter]

I will politely agree to disagree and move on about the water/hydrogen explosion. Thanks for the input.

[John Holland]

I'm not quite sure where this fits into this discussion about water, but here is my personal experience: About 25-30 years ago I stayed over after the National. I had collected a lot of lead from the backstop and was smelting that salvaged lead at our camp site. I was nearly finished when it started to rain. I had a 20 pound pot ready to ladle out into ingot moulds. My helper grabbed an umbrella and held it over me and the pot to keep the water out of it. Just as I reached out for the first ladle full, the umbrella tipped and the rain water ran off the edge right into the pot. In less than a blink of an eye the entire 20 pounds of molten lead exploded like a volcano! My helper and I both turned our faces fast enough to avoid any burns on them. However, the molten lead went straight up the sleeve of my outstretched arm which was holding the ladle, and burned my arm pretty good. The denim jackets and jeans we were wearing had protected most everything else, except for my helper's hand which had been holding the umbrella. The umbrella itself was coated on the inside with lead, too. My helper's hand was also burned. The pot itself was completely empty of every ounce of the 20 pounds of molten which it had held only a milisecond earlier!

[Maillemaker]

Once I was renting an apartment up in New York, and was trying my hand at tin-plating some chainmail armor. This was before I had discovered black powder shooting.

I had a cake pan on the gas stove, and melted some tin in it. I then applied this liquid flux, called "Ruby Fluid", to the maille, and dipped it in the molten tin. Most likely the tin was not very hot and so the tin solidified around the maille and made a solid mess. I decided to re-dip it and leave it in the molten tin to try and let some of the tin re-melt and possibly run off.

So I did this, and suddenly there was an explosion that sounded like a .45 ACP going off! It blasted little tiny bits of tin everywhere. Fortunately it was not very hot and I did not get burned - but there were little tiny bits of tin all over that kitchen. I spent weeks with a plastic knife picking bits of tin off of the ceiling, the walls, the side of the refrigerator, the stove, the floor - you name it.

My guess is that some of that liquid flux was trapped under the initial tin and when I put it back in the pot it flashed into steam.

When casting bullets, I drop into water. I never put bad bullets back into a molten pot for fear of getting water into the melt. But from time to time I have gotten a drop of water in the pot. Most of the time, you get a sizzle or a "pop-spit". My guess is as long as the water sits on top of the melt it will vaporize fairly harmlessly. But if it gets any depth into the lead at all watch out!

Steve