As I lay my track on the prepared roadbed, I use a 50-50 mixture of white glue and water, which makes for good bonding and relatively easy removal when the first law of man is encountered - I screwed up!! To ensure a good seating I lay red bricks, end to end, on the tracks that I have glued. I leave the bricks in position over night. At the end of the next day, I do another section of track, etc. The amount I do in each session is dictated by the number of bricks on hand. After all of the mainline track was in position, I began the ballasting of all of the visible track. Guess what!? With all of the starting, and stopping, of the glue down process, two days ago I found about a foot of track that was not glued. This was discovered after I had spread the ballast and was in the brushing step to get the excess ballast out of the way. I saw movement of the track as I brushed. I thought of the hassle to take up all of the loose ballast that was in place in the involved area. I decided to try something else. See if the ballasting process will secure the section. I know that in 1:1 rail laying that part of the function of the ballast is position retention. In the model railroad situation glue is added to the characteristics of the ballast. Maybe this will serve to tie down this section that is loose! The next day I was pleased to find that the section in question was firmly in place and I was ready to go on to the next section.
I hope the poster doesn't mind some comments? I have come to rely on the glued ballast to do all that real ballast does as well. I use a very thin sheen of acrylic latex caulk to fix my track elements in place (except for turnouts...they are more often troublesome and occasionally have to be lifted out and replaced/repaired). I use soda or soup/vegetable tins on their sides atop the rails for weight. Bricks are very heavy, and I would want very sturdy and well-groomed sub-roadbed below the track elements so that the bricks didn't end up making vertical waves in the rails. Either way, bricks certainly would keep the tracks in their places and weighted down. I think any water-soluble glue diluted is a good fixative for ballast grains. I happen to have enjoyed success with plain old carpenter's yellow glue diluted in favour of water by near 6/1. IOW, a very light solution. Later, when I introduce a new engine to the layout, I almost always have to tweak the rail levels on a curve. This was so bad in the case of my brass hybrid 2-10-2 from BLI that I had to rip up and re-level the roadbed on one very broad curve. Softening the ballast was as easy as wetting it and waiting 20 minutes....up it all came, scraped, added some shims, relaid the track, and then ballasted it once again. Final step was to paint the rails once more. Lifting the outer rail just 1/32" was all that was needed to keep the long Genesis SD75M's from wanting to go straight instead of follow the curve.
