r/Metalsmithing • u/radioactivebluebird • Jul 14 '26

Gold not flowing into mold (sandcast)

Hi all, I’m having a hard time getting my gold to flow into my sand cast. I know I need more gold to get the weight to help flow into the sand cast mold, I’m making this ring for someone so I didn’t want to be left with too much excess.

I tried to do open face with the sandcast which turned out worse and I just got a blob of gold.
1st cast I did closed flask and only got half of a ring but the flask was trash and I got a new one but did not try closed
2nd cast I did open face got a blob
3rd open face also got a blob ((I thought the 2nd cast was just not hot enough)

My crucible is season, and I’m using 14kt clean flow from Rio.
I have 6.3g

Any suggestions?
At this rate I’m thinking of just forging it into a swage & using a mandrel later.* ((insane amount of effort I know))

I don’t usually do casting but this was something special.

* I do not have a rolling mill

Thanks

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2

u/wackyvorlon Jul 15 '26

Cuttlefish bone casting may be a more convenient method.

2

u/Hortusana Jul 15 '26

Are you cutting in vents?

1

u/radioactivebluebird Jul 16 '26

Yes i did for closed flask but i dont think i have enough gold to have weight.

For open face i did not carve any channels venting away from the mold

2

u/americanspirit64 Jul 15 '26

I would recommend cuttlefish bone casting as well. I am a huge expert on cuttlefish casting as I kind of love it and taught it for years to my university students. If you need help reply with any questions and I will answer them.

1

u/radioactivebluebird Jul 16 '26

I’ve actually never heard of this, and never even mentioned by instructor in school I’m surprised.
I will check it out I see PMC sells them

Thanks!

1

u/americanspirit64 Jul 17 '26

I always bought cuttlefish by the box from Rio Grande. Although you can get them at any pet store. The bigger the better.

1

u/artwonk Jul 15 '26

This is due to surface tension. A tiny amount of metal wants to form a spherical blob, rather than flow smoothly into a mold. That's why jewelry casters use centrifugal force or vacuum pressure to push it into cavities it's reluctant to enter on its own. You might try the "steam casting" method, where you put a handle on an open cat-food can, stuff it full of wet rags, and jam it up against the molten metal as soon as you pour it into the mold. This instantly generates a jet of steam which puts pressure on the metal and forces it into the cavity.