If there’s one question I see over and over again, it’s what to use to fill in the gaps between the three ties that American Flyer, Lionel, and Marx put under their track.
I don’t recall anyone else ever suggesting what I do: I salvage the ties off discarded, rusty, or otherwise damaged and unusable track.
I had plenty of track to salvage ties from. When my dad’s trains were in storage, about 1/3 of his track survived it perfectly, and I’m still using that track on my layout today, more than 60 years after he used it. But a good 2/3 of his track emerged from storage rusty. I ended up prying the ties off the unusable track, repainting the rusty ties if they needed it–a lot of them didn’t–and then putting those ties under the track I had elected to use, cinching the ties back down with a small screwdriver. Inspect each insulator to make sure it’s in good shape, and be sure it stays in place when re-using the tie, or replace it with a piece of thin cardboard or plastic salvaged from a 2-liter soda bottle.
A drop of glue can help hold them in place if friction doesn’t hold them in place on their own. On straight pieces, two ties in between each original tie looks about right. On a wide-radius curve, I’ll usually put three in between each.
The resulting track looks a little more realistic than the track’s original appearance while still looking like traditional toy train track.
If you don’t have a box full of rusty track to use, ask your local hobby shop. Often when they buy trains from the public, they get track that’s in too bad of shape to use. They’ll probably just throw the track away, so they’d be glad to sell it to you very cheaply.
For that matter, most of the shops around me sell standard curved track for 25 cents per section. Try to pick out the worst track out of those boxes–be nice and save the most usable stuff for someone who needs the whole thing–and you can probably get enough ties to outfit your layout for a few dollars. If you let the shop owner know what you’re doing, he or she will probably cut you a bit of a break on the price.
While it’s a bit of work to salvage those ties, it doesn’t require any special tools. I don’t think it’s any more work than cutting strips of wood and I don’t think it’s any more expensive than using wood. Cutting ties from hardboard is probably cheaper, but it requires a scroll saw, and cutting all those ties is probably more time consuming.