The pink foam base is glued to the framework with Locktite PL300 foam board glue. It takes a while to set but works well. I lay most sections of track on the foam base on a tabletop and then move it to the layout framework. Easier to work on track this way. Picture shows one 8' section under construction on my pool table.
I lay the ties directly onto the foam base gluing them with Elmers white glue. Rail is set with Walthers Goo which is a contact cement. I apply the Goo to the bottom of the rail and let it dry, then put the rail in place and heat the rail with a soldering iron to soften the glue and set it. It can be reheated to reposition it if needed. My spikes are deceiving. I spike only the viewable side just for appearance. Any areas where I have a problem with track staying put I fix with thin CA.
Another small model added today. I made the fuel tank from a piece of PVC wrapped with card stock. The stand is also made from card stock. Rivets are glue drops. Painted with acrylics and blended into scenery base.
We also had a saying "fine as frogs hair". Very nice Bob - your modeling is so "atmospheric". Have followed your other projects on different boards and must say they do inspire. I also was first "grabbed" by the Maine 2 footers and still love them however the industrial-estate sized lines are so addicting. Keep up the great work.
Great tank. It's the little touches, so often omitted, that count so much. The old rag hung over the beam to wipe your hands, the scrap roofing to avoid standing in a puddle---you are awarded Herb's honorarium for May.
____________________ Fix it again, Mr Gates--it still works!"
PVA alone would not be adequate. It sticks fairly well but the addition of ballast creates more than enough adhesion. When I have removed track the ballast and ties were not easy to remove and usually some of the foam comes up with them. I have display layouts that are moved frequently and have not had any problems.
I used some cheap builder's merchant straight PVA last night to stick down a few timber ties - but to rigid foamed PU insulation; I don't have any blue/pink extruded styrene in stock. This morning the ties are firmly fixed, though the PU may have a more PVA compatible surface finish than extruded styrene foam.
Like yourself, I am planning on also retaining the ties with PVA'ed ballast.