ggw d sands testing, page-7

Harry,
that was interested me,fill to spill point.
No idea about this but why spend the brass on 3d if you have this sitting under your nose?Wouldn't you concentrate on getting that out to free up some cash and then do the 3d?
Very uneducated here so cut me a bit of slack,I'm sure its not that simple.
Fill to the spill point to me means nearly overflowing.