Guys-
After reading on a list I'm on that some guys were using some kind of sandblasting grit to represent scale coal loads, I went to a vendor in Knoxville today called Sandmasters. They had a product called "Black Beauty" sandblasting media.
It looks like real nice, washed coal. It is pretty heavy, and says that it is actually coal slag. It appears to have very little dust, and is non-magnetic.
There were three sizes, and I got a bag of the finest to experiment with for N-scale. I'm just guessing here, but I would think the HO sizes would be around 1" for the fine, 2" for the next size, and 4" for the largest, with a little bit of variation in each bag.
The dealer only sells in 100 lb. bags, but a bag is cheap at a little over $9.00. More than a lifetime supply for most of us, and it would be perfect to split a bag of each between members.
Considering that Woodland scenics coal is really charcoal, and is $10.00 for 32 oz., 100 lbs. for $9.00 is pretty incredible!
Anyhoo, hope this helps,
- Phil