Zinc casting question

[Drov]

Hello, I'm new, just joined. I have a "what would happen if?" question.

If I had a stainless steel half sphere - the shape of half a tennis ball, placed a copper tube coil inside that steel half ball shape - then poured zinc into the ball - encasing the copper coil to the brim, what would happen?

Would the copper coil remain "cast-in" the steel when cooled - or could I remove it from the steel?

I am trying to "cast-in" a copper tube coil inside zinc as a solid piece - but have the smooth round shape of half a tennis ball - half an egg - etc.

Also, would the molten zinc destroy the copper tube? I am trying to fabricate a custom heater element for a prototype of an invention.

I appreciate any help. Kind regards.

[Michael G]

Zinc melts at 300 or 400 degrees C from memory, copper at 2 or 3 times that, so the copper would not be destroyed in contact with molten zinc although it may partially anneal it.

Michael

[russ57]

I'd doubt you would be able to remove the zinc from the steel. Pretty much how you galvanise something.
But you could use the steel to make a sand mould and pour into that.

Or a tennis ball for that matter!


Russ

[OxxAndBert]

There are also lower melting point alloys that might be an option if it doesn't HAVE to be zinc.
This will give you an idea of the sort of thing that's available: https://www.william-rowland.com/pages/low-melting-point-alloy

Steve

[kwijibo99]

Your best bet for being able to remove the stainless half sphere mould would be to give it a good coating of carbon black using an acetylene torch with no oxygen. If you don't have acetylene then a kerosene flame might do at a pinch.
As your project is a one off at this point in time and zinc has a low melting temperature, perhaps a plaster mould, well dried in an oven, might be an option.

[Drov]

Thanks to everyone for the replies - they all helped me understand and re-think what it is I want to accomplish.

The part I need to make is for pure water processing so the shell of my heater element needs to stainless or zinc. The copper coil needs to completely cast-in either stainless or zinc. So a basic sand mold sounds like the easiest for me. I just want to get that coil completely encased with a nice smooth egg-like contour. I think I might have to suspend the coil a little bit, from the bottom and sides of the sand mold, so that when I pour the zinc, it encases the coil nice and round.

I know enough now to give both methods a try. Will post results.

Thanks again - David