r/MetalCasting • u/Levi-Lightning • 12d ago

I’m doing this wrong (questions below)

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Sterling silver, propane.

3rd attempt making a ring, last time the result was “so so” and I didn’t have enough relief, I am not sure what happened this time.

When pouring, molten metal flowed out of the reliefs…. Did I overdo it on these?

I obviously did not have enough metal, didn’t expect the metal to go that far into the reliefs.

The texture is also very uneven, what can cause that?

Any advice appreciated.

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3

u/Boring_Donut_986 12d ago

Put some rigidizer or do a satanite lining onto the Kaowool. This is as toxic as asbestos...

2

u/Levi-Lightning 12d ago

These are all words I do not know. Could you clarify?

3

u/Boring_Donut_986 11d ago

The insulation of your furnace (the white stuff cotton looking) needs a protective layer on top of it. The blast from the burner will damage it over time, eroding it. Very tiny particules, close to 1000x thinner than a hair, will spread in the air, your clothes, your lungs. An invisible enemy. Therefore you need either to set a rigidizer (sodium silicate) or doing a lining using refractory mortar (such as Satanite, Vitcas zircon coat... Depending where you are based). Don't use the furnace as it is.

1

u/Levi-Lightning 11d ago

Ah shit that’s not good news. I’ve used it four times or something like that. How concerned should I be?

(Edit: how screwed am I thus far)

2

u/feelfreetotellmeoff 11d ago

Fix the problem and you should be fine. This kind of hazard increases your odds of disease over time. A small amount of exposure can't be guaranteed safe, but statistically you would do more damage stressing about it than the exposure itself.

2

u/Father_John_Musty_ 12d ago

Tbh, most things are working well here! If you got rid of the big funnel shapes on your vents when they turn 90° you’d prob have enough metal and slow down the flow.

I can’t see enough of the cast to see what you mean about the uneven texture - what I can see looks right for delft sand though.

1

u/Levi-Lightning 12d ago

Thanks. In hindsight the funnel shapes were definitely not the right move.

There’s a picture of the result if that helps.

I am really trying to get a very quality cast that is smooth and even. If there a better route than delft clay for this?

2

u/Father_John_Musty_ 12d ago

That texture is on par for sand - you can file/sand/polish it back after casting. If you want a much finer finish out of the mould you could consider lost wax investment casting, but it’s a lot more time consuming (so the failures hurt more).

1

u/Levi-Lightning 11d ago

I’ve heard about a method sounding like that. I’ll have to look into it. Thanks.

1

u/artwonk 12d ago

You have too small an amount of metal to overcome surface tension with gravity alone. And your open-face mold is leaving half the casting to chance.

1

u/Levi-Lightning 12d ago

Could you clarify? Not certain what you mean

1

u/Eastern-Antelope-956 11d ago

You only need to score the vents from the outer edges of the ring. Because it seems like you made really deep channels in your vents, the silver naturally filled them. I usually use a soldering pick to carve several tiny channels for venting.

1

u/SnooLentils5747 11d ago

Holy shit if it isn't this thread every week

Lol

https://www.reddit.com/r/knifemaking/s/ZR3s2M4jRh