sentinel
You might try what I do. My local "Rock Shop" (boulders, large rocks, gravel, and such) sells crusher fines in two forms. First is straight crusher fines. Second is crusher fines with a polymer additive. The additive is a bonding agent, it is a "re-bonding" agent. Don't know the correct name but here is how it works, it is designed for driveways and pathways, tamp it into place then wet it down, the additive "glues" it together. If it chips, just "crunch it up" tamp it back into the whole and wet it down to reactive the additive. As track ballast, I put it down and wet it. When I need to pull up a track section, I spend a few minutes crunching it up, and put it back down and re-wet it. Works great and I love it. It puts an absolute stop to ballast migration and is totally reusable, unlike many other gluing options. Check with your local "rock shop" for details.
Tom Trigg
I have an ourdoor railroad in Northern Indiana and have used cement blocks for the base over a perferated drain tile and crushed limestone in clay, it works great; through 4 winters and no movement. However, I use crushed lime stone for ballast but it doesn't hold. Does anyone have any suggestions for securing the ballast and still keep it looking realistic. Indoors you can use White Glue but outdoors is a different story. I was thinking clear epoxy but I could never change the track.
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