Good evening all,
The subject ballast if occupying my mind for a while now but I have come up with a solution. First i used aquarium grid but as my station is placed on a board, it makes the whole thing pretty heavy.
But then I bought a bag of Grow more perlite, the granular diameter is about right but has some fines in it. Then I got some cheap grey plastic primer to the colour I like ( grey) and modified an old plastic bucket for being the spraying chamber.
The perlite fly's pretty well ones start spraying with the spray can. But once the bucket is loaded , spray the top layer and then shake it all and keep on spraying till the desired effect is reached . At the same time the small fines getting blasted away and I ended up with granules I want ready to use as ballast. Once the ballast is spread in on the tracks and brushed even , a wood glue washing liquid solution is getting put on it and with a bit of luck , the whole thing is dry by the next day!
have a good weekend