Typical example of what happens when accountants exert undue influence in management.
It was the storing outside that gave the castings their stability … they would have been exposed to summer heat, and also to freezing temperatures … this thermal cycling was (and is) crucial to achieving stability in iron castings.
Its the cycling of warm to cold, and then the number of. The idea is that cast iron is brittle and prone to cracking, and the cycling might prevent significant cracks forming when its exposed to in-use heat cycles.
On a normal day,there’s only the one cycle as the sun heats up the day and then then night cools things down.
So its possible that the drain water was warm and cold, adding more cycles.
On the other hand, the salts would cause corrosion ? Well cast iron is particularly slow to corrode…
Not so. Normally water’s high thermal conductivity and high heat capacity more than compensate for its greater Leidenfrost effect, resulting in faster quenching than with oil quenching.
In general, cooling rates for various quench media are as follows: water quench > oil quench > air quench > furnace quench.
The quenching thing is probably a lot more complex than just choosing between oil and water. There will be a big difference in the way you would quench a sword and a horse shoe. If uneven cooling causes the show to warp it can be readily heated and pounded back into shape. A sword may be ruined requiring much more rework if the quenching causes uneven cooling. Massive parts may have many more considerations including the hot and cold cycling.
The part about pissing on castings does sound kind of hokey, but maybe it’s purpose is to rapidly promote corrosion on the surface of the casting which could provide some stress relief. Or maybe it’s started with a prank, telling someone they had to go take a leak on their casting every day so it wouldn’t get ruined. That one might have lost popularity after left-handed screwdrivers and sky hooks were invented.
When I was a kid, a friend of my parents was telling a story where he was in Mexico and a rock broke the oilpan on his motorcycle. He said the locals mixed clay and urine to patch the hole and when it dried, it was hard as steel. He said they jammed a screwdriver straight into the patch and it did nothing. As a kid I believed it, but now I’m wondering if that’s true. Is there anything special about mixing urine and clay? Or did they use urine because it was all they had and water would have worked just as well.
I saw a documentary on Russian prisons that discussed their tattoos. They used electric razors to make a tattooing gun, and for ink they used a mixture of soot and urine. One prisoner pointed out that a lot of prisoners have diseases so you want to use your own urine.
Imagine the only physical things that your community has access to are rocks, sticks, dirt, plants, water, whatever animals you can catch and the rare piece of expensive metal. This is it. It’s all you have to make shelter and the things for daily life from. That’s all the kids have to play with. When the teenagers hang out on the weekends, that’s what they have around them.
It’s not going to be long before you guys understand the properties of all of those materials. Between experimentation and chance, you are going to know these things inside and out. There are only so many combinations you can come up with.
For leather, there are a million ways to figure it out. The baby keeps peeing on the hide being used as a blanket. Someone tries to store urine in a skin bag while it’s too cold to go outside to pee. Someone notices that urine has a strong smell, and figures that like most things with a strong smell it probably has some interesting properties.
The same with clothes. Clothing gets soaked with urine all the time, especially in the days before diapers.
“Smitkins! What the hell are you doing out here pissing on company property?!”
“Well, uh, you see boss, uh… it hardens the castings faster. Yeah, that’s it - it hardens the casting faster, I’m trying to improve the quality of our product!”
“oh, good idea. I’ll order everyone to pee out here on the castings from now on.”