Weighing Freight Car Models with Liquid Gravity
I found a product called Liquid Gravity from Deluxe Materials from the UK the other day in a catalog a friend gave me. Although it is apparently not new has anyone every used it to weight flat cars or gondolas. It appears to be very small pellets of non toxic material that is pour able and fixed in place with CA glue. Looks to be available on Amazon as well
Below is a link to the product and a video on its use.