03-26-2017, 07:48 PM
I've no experience whatsoever on casting small detail parts, but Steve's suggestion of a casting resin which flows more readily sounds reasonable to me.
However, were I casting such small parts, I'd simply mix a small batch of JB QwikWeld, then with an old #11 blade in my X-Acto, dip its tip onto the epoxy and poke that little bit into the cavity in the mould. Quickly do so with all of the mould cavities, then, since it flows quite readily, repeat the process, starting with the one first-done, which should fill or over-fill the cavities. Next, use a #18 chisel-type blade, and drag it over each little mound of not-yet-cured epoxy, and, assuming there's a cover for the mould, quickly put it in place.
This epoxy sets in 5 or 6 minutes and supposedly cures in 40 minutes.
I think that the act of placing the material into the mould cavities, rather than simply pouring it in, is less likely to create air inclusions (bubbles in the finished castings) and the contact of the blade's tip against the mould should help to break the surface tension of the epoxy, allowing it to flow more freely.
Naturally, I can't say for sure that this will work, but it certainly wouldn't be too expensive to try, as you don't need to create another mould.
I have found that the contact factor (using a bit of the casting material on a tool to touch the mould's interior) helped when making large castings using plaster. Also, for large castings, vibrating the just-filled mould often helps to remove included air, though I doubt it would have any effect on such small parts.
Wayne
However, were I casting such small parts, I'd simply mix a small batch of JB QwikWeld, then with an old #11 blade in my X-Acto, dip its tip onto the epoxy and poke that little bit into the cavity in the mould. Quickly do so with all of the mould cavities, then, since it flows quite readily, repeat the process, starting with the one first-done, which should fill or over-fill the cavities. Next, use a #18 chisel-type blade, and drag it over each little mound of not-yet-cured epoxy, and, assuming there's a cover for the mould, quickly put it in place.
This epoxy sets in 5 or 6 minutes and supposedly cures in 40 minutes.
I think that the act of placing the material into the mould cavities, rather than simply pouring it in, is less likely to create air inclusions (bubbles in the finished castings) and the contact of the blade's tip against the mould should help to break the surface tension of the epoxy, allowing it to flow more freely.
Naturally, I can't say for sure that this will work, but it certainly wouldn't be too expensive to try, as you don't need to create another mould.
I have found that the contact factor (using a bit of the casting material on a tool to touch the mould's interior) helped when making large castings using plaster. Also, for large castings, vibrating the just-filled mould often helps to remove included air, though I doubt it would have any effect on such small parts.
Wayne