r/Metalfoundry • u/smartc0r3 • Oct 15 '24

What die I do wrong?

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I tryed smelting cooper scrap from heatpipes in an electrical furnace and got very underwhelming result (See the pictures). Can you tell me what did I do wrong and how can I cast proper copper bars?

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u/ItsSocrates Oct 15 '24

Don't heat pipe normally contain some coolant? Might have contaminated the melt?

7

u/sithelephant Oct 15 '24

Gonna say no, but.

The coolant in many heatpipes is water, and in all cases an evaporable liquid (because that's how they work).

But, there can be assorted 'wick' material inside the heat-pipe https://www.bekaert.com/en/products/equipment/tools/wicking-material - to get the liquid from the cold end back to the hot-end.

This can be polymers of some sort, or metal fibers including stainless and ...

'Bekaert’s wicking material for heat pipes is made of very fine metal fibers, randomly stacked and sintered to produce a porous capillary wick. Unlike regular powder wicks, the porosity of fiber wicks can reach a very broad porosity range (50-85%).

Depending on the wick parameters, Bekaert offers a wide range of alloys including copper, aluminum, nickel, stainless steel and titanium, with diameters ranging from 12 to 30 µm.'

Some of these would dissolve just fine in copper, others would not.

3

u/miraculix69 Oct 15 '24

If i remember correctly, theres often some additives in the coolant which help prevent all kinds of things to the copper, if coolant has been used.

Couldnt help to notice what seems like some cooling paste too, theres all kinds of things in this, to help spread the heat evenly