Robert Howle wrote:PS: A hollow print that is castable will not matter in direct casting as the investment only molds to the surface, therefore hollow prints or waxes should cast the same.
But wouldn't the caveat be that if you have enclosed hollow spaces, the total weight of the model will be off and your calculation of metal required be too little?
Odds are you have overkill for the button, so it may not make a difference.
Honestly, if you calculate your weights of metal to cast to the point of having NO button left after casting then yes it could be a factor.
Technically you are correct if that is your point, but in reality in this ring or any other ring that would be intentionally left hallow even if the hallow area is not filled with investment during the vacuum process, which could easily happen and cause worse results of free unsupported investment flowing into the rest of the casting, that amount of added weight would be insignificant to account for individually.
Now if you had 10 of these rings that cast solid considering what Robert has stated and is true, you might have a miscalculation that could reduce the button weight to maybe half it's size.
But most people cast using enough metal that any discrepancy in the calculated weight of a ring would be compensated by the button.
In the case of the ring that is being discussed here on this forum the amount of "hallow" area is only going to result in tenths of grams.