Can someone with experience using their Scenic Cement and Matte Medium tell me their differences, their uses and how do they compare to white glue? Thank you.
All the manufacturers glues work well. I have used Scenic Express matte medium with excellent results. With that said I found a less expensive material - https://www.youtube.com/watch?v=rphfWlU_elk. This is Mod Podge Matte. It can be used diluted or full strength as shown in the video.
Scenic Express matte medium and Mod Podge Matte medium are acrylic artists' mediums. They both dry to a clear, flat, no sheen finish. Although they are water-soluble in the bottle, they are virtually water-proof when dry. Mod Podge can be thinned down as much as you want with plain water before applying it. It can be used for ballasting and all other scenery applications.
On a side note, Mod Podge Gloss dries with a super-shiny finish, which can be used for water effects on a layout. For quick, easy water surfaces, merely paint a flat surface with a suitable flat latex color, then after it dries brush some full-strength gloss over it and let it dry. Instant fast, easy, pond, small lake, or waterway. It'll do until something better comes along.
Elmer's Glue All (I wouldn't use any other white glue if you can avoid it) is virtually the same as the acrylic artists matte medium, with one big exception: it is NOT water-proof when dry. You can actually re-soften it with water applications anytime you wish.
If I want some scenery to hold tight whether damp or not, I'l use artists acrylic medium. For instance, I use it when building trees. If I plant trees on my layout, then come back later to do some more scenery work, I don't want the foliage softening up and dripping off the branches because I had to spray on some water for some ground work. Or like-wise if I have added some ground cover to near-vertical or very steep rock walls and hills. I'll fix that ground cover on with the matte medium and not worry about it coming loose if later it gets misted while doing some other close-by ground cover.
On the other hand, if the scenery glue softening up is not that big a deal, I prefer to use Elmer's Glue All as my cement. This can be a real advantage if you ever want to change the ground cover someday for some reason. And I always use the Glue-All for ballasting my track. If the time ever comes where I want to remove track and re-use it or sell it off, it's a lot easier to soak the ballast loose as opposed to cleaning it off with a hammer and chisel, which is what it would take if you ballasted with acrylic medium.
To sum it up, Elmer's Glue All and artist's acrylic medium both work equally well. Just try and decide what you want it, or need it, to do in the future. Water-proof when dry, or water-soluble? Your choice.
For what it's worth, the Matte Medium and/or "Mod Podge" never dries totally hard, like white glue does. Thus, ballasting with Matte Medium, instead of whit glue, tends to offer sound deadening to the track.
Also, once set, the Matte Medium and/or "Mod Podge" can be softened/removed by applying 70% cheap alcohol.
We use the Scenic Express one gallon jugs of Matte Medium, thinned to the consistency of whole milk, for everything on the layout, i.e. ballast, scenery, and securing buildings/structures.