Forge World not using vents?

[Feldspar]

Hey everybody,

I recently purchased this guy from Forge World. The model is a few years old and the casting is fantastic. Very slight mold lines, crisp details and no sign of vents on the bottom of the cast.

Can any of you tell me how thin details like this are possible without vents?

All I see are large v-shaped gates with nowhere for the air to go if it gets trapped under the pour. However, the tops of the gates are slightly concave and smooth indicating to me it was indeed a gravity mold, probably under pressure due to the lack of bubbles.

When I try to cast something like this with long thin details like the claws, without vents, I almost always get gaps and bubbles.





Would love to know how this is done for my own work.

Thanks,

FS

[Fleafa]

Vacuum degassing, I expect. I would have no trouble casting parts like that with gravity-poured, split moulds using vacuum & pressure, the same as many people here.

[RageofAchilles]

Absolutely! When doing standard atmo gravity casting small details like the ones your talking about would rarely come out right, air bubbles love to sit in places like that.

Then I got a Vacuum setup and found that the expansion it causes forces resin into every nook and cranny, but I was left with cavities in my castings.

Having recently got together a pressure setup, the combination of the two disciplines ,gives fine detail and bubble free castings.

[Feldspar]

Thanks guys. I'll give it a shot.