A long-time club member and probably the most knowledgeable member of our group says he uses crushed limestone as ballast. He sifts out the larger pieces.
Anyone heard of this?
I’ve used sifted quarter-down crushed limestone. It needs two siftings. The first separates out the larger particles which can be used for rocks or rip-rap. The second sifts out the dust and too-small particles which are discarded. But, the colour doesn’t seem right to me as it’s a light tan colour, and any ballast I’ve seen is dark, almost black.
Try a india ink /alcohol stain on the limestone to darken it. It is quite porous.
That sounds about right, to me, Chip, what the others have said. I woud go a step further and wa***he end product that you feel is the right size to rid it of dust. Although limestone will dissolve in water, it takes a long, long, time, so don’t worry about washing it. I have never used the india ink technique, but so many roaders describe their success with it that it has to be good.
If you decide to go that way, would you help out all of the new people who joined recently, or who will join in the next few weeks, and tell us how it worked for you? The ballasting questions are unrelenting on this forum, so it is a point of concern for all new folks.
Before limestone would dissolve in water, the water would have be fairly acidic.