Author Topic: Resurrection of a CFEI 100 KVA Induction Furnace  (Read 25808 times)

Online vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #625 on: January 11, 2021, 01:46:12 PM »
Snap flasks. Cool. Do you have any photos of the pistons, Andrew?  :thumbup:
I love it when a Plan B comes together!
Steve
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Offline mattinker

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #626 on: January 12, 2021, 07:05:08 AM »
Andrew,

I can see snap flasks as being really useful with lost PLA in silica sand Sodium Silicate molds! Burning out the PLA would be better without the flask! I use petrobond so it's not the same problem for me yet, I have just bought a really cheep 3D printer, which because it's cheep, is proving to be somewhat challenging to get together! I have a foundry supplier near me so I was thinking of going the other route, investment plaster for lost PLA, My kiln, which is vertical, "200liter oil drum gas fired) top opening will allow me to pour molds hot without removing them.

Cheers, Matthew

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #627 on: January 12, 2021, 10:55:14 AM »
I'm wondering if those piston molds are baked or solidified somehow (sodium silicate?) because it looks like they are meant to be stood up from their present positions. Without a flask, that would seem difficult. Well, maybe the flasks were replaced for the turnng operation?

I'm guessing the cone ended hollows are giant sprues. Or if they aren't meant to be poured that way, and lie on their sides, what prevents the horizontal cores from popping out during the pour if there is no flask to hold them in place?

What's the scale of this -- maybe it's smaller than I imagine. I was thinking full size engine pistons, but if this is model scale, it would be easier to understand and the sprues might actually be small.
I love it when a Plan B comes together!
Steve
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Online awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #628 on: January 12, 2021, 11:12:52 AM »
Steve,

A/ They were for 1 inch finished diameter pistons

B/ The sand was silver sand and 4 % sodium silicate

C/ They were stacked vertically, several at a time, and clamped with a sash clamp

D/ The alloy was one of the LM series from a scrapped large Diesel engine piston

E/ Initial ingotting was a pain due to steel reinforcement in the original pistons

They turned out rather well. The white colour is parting powder. It must be 15 years since I did them!


Andrew Mawson
East Sussex

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #629 on: January 12, 2021, 11:48:39 AM »
Thanks, Andrew!
I love it when a Plan B comes together!
Steve
www.sredmond.com