It's a long held belief that getting even a drop of water in a pot of molten lead will cause a tremendous explosion from the quickly boiling water.
I'm an experienced welder and spent a little time in college as a foundry apprentice and did quite a bit of casting aluminum, so I like to think I have a little knowledge on this subject, but I'm not an expert.
Foundry sand contains an oil, and a percentage of moisture. When using foundry sand that is too dry (or been used too many times), you add some annealing oil to make it bind because it doesn't dry up. I've heard of using water as a binder for foundry sand, but all the moisture that is left in a mold will leave 'dimples' on any part of the casting as the air has no way to escape. This is true of aluminum, I have never casted lead into a sand mold.
I started casting for the season the other day. It was a mostly cloudy day, no forecast for rain. set up the pot outside, started casting, then sprinkles and of course rain. I unplugged my pot and ran inside just before the rain started coming down hard, and I'm sure that the pot was still molten. I thought I was going to have to scrape lead off my bricks for months, then I looked out the window and saw nothing at all like what I was expecting. Rain was falling into the pot, on everything else... no explosion.
Granted this was rain, not like I poured a bucket of water into my pot somehow. The only evidence was little craters in the top of the now-hardened lead.
I got into a discusssion on another thread about this where mention was made of "the lead must have cooled off very quickly" or "unless water gets under the surface of the lead you won't get an explosion"
does anyone have any experience, or know anyone, who has ever actually 'exploded' a pot of lead from putting in a wet ingot or wheel weight...or somehow putting water into the pot intentionally. Please, no "my brother's friend's cousin-in-law told me" experiences.
Thanks!
I'm an experienced welder and spent a little time in college as a foundry apprentice and did quite a bit of casting aluminum, so I like to think I have a little knowledge on this subject, but I'm not an expert.
Foundry sand contains an oil, and a percentage of moisture. When using foundry sand that is too dry (or been used too many times), you add some annealing oil to make it bind because it doesn't dry up. I've heard of using water as a binder for foundry sand, but all the moisture that is left in a mold will leave 'dimples' on any part of the casting as the air has no way to escape. This is true of aluminum, I have never casted lead into a sand mold.
I started casting for the season the other day. It was a mostly cloudy day, no forecast for rain. set up the pot outside, started casting, then sprinkles and of course rain. I unplugged my pot and ran inside just before the rain started coming down hard, and I'm sure that the pot was still molten. I thought I was going to have to scrape lead off my bricks for months, then I looked out the window and saw nothing at all like what I was expecting. Rain was falling into the pot, on everything else... no explosion.
Granted this was rain, not like I poured a bucket of water into my pot somehow. The only evidence was little craters in the top of the now-hardened lead.
I got into a discusssion on another thread about this where mention was made of "the lead must have cooled off very quickly" or "unless water gets under the surface of the lead you won't get an explosion"
does anyone have any experience, or know anyone, who has ever actually 'exploded' a pot of lead from putting in a wet ingot or wheel weight...or somehow putting water into the pot intentionally. Please, no "my brother's friend's cousin-in-law told me" experiences.
Thanks!