Help - matte medium problem

[nachoman]

Before trying a different glue, I went back over my technique and tried something different. I mixed my glue to 75% glue, 25% water - the thinning recommendation on the Liquitex bottle. I added no dishwashing detergent to the glue and used an alcohol/water mix to wet the dirt. If anything, the white staining was worse. To make sure it wasn't the dirt, I tried again using dilute white glue as I always did in the past - and it looks great. I think I will stick to just using white glue from now on. After P5se's experience with extreme humidity changes, I am much less worried about the white glue holding up. Thanks for the advice, everyone.

PS, perhaps I will have a photo of my ballasted track in next week's photo thread