Hey Haydn,
This my sound funny but I use "Mother Nature's" dirt to make the runways.
I will work at the dirt till its a "fine" course(sand like). I do this by grinding the dirt w/ a solid block.
Then when it is time to apply the dirt, I mix water and white glue(Elmers glue) together(ratio of water to white glue is up to you).
After that is done I'll use an ol brush to apply the mix to the areas that I want then I will put on the dirt. I'll keep doing this till I'm satisfied w/ the results.
This is one of a million(LOL)ways to make a runway.
Flaps up,Mike
If you would listen to everybody about the inaccuracies, most of the kits on your shelf would not have been built Too Close For Guns, Switching To Finger