Are you supposed to remove the first tie on each section of flex track in order to join it together? If so, what do you do with the area the ties came from, glue the ties back in place?
Jacon
That’s what I do–after removing the first tie on each section of flextrack and joining the track (ideally soldering the ends of the track to each other,) I shave off the molded “spikes” on the cut-off plastic tie, trimming a little extra to make up for the thickness of the rail joiner. Then I slip it carefully under the rail joiner to match the spacing of the other ties. When ballast and glue are applied the tie will be firmly mounted in place.
Whew! Thanks Jetrock, I just knew I had screwed up some sections… 
Jacon
after removing a tie from each end of the flex track and soldering the rail joiners, there are two things you can do to replace the tie…one, save the old tie, file it down smooth, and glue it under the rails where the ties are missing, or you can purchase a piece of strip balsa wood from a craft center (Hobby Lobby has them) the same dimetions of the tie, cut it to length, paint it with flat black or rail brown paint on three sides, and glue it in place under the rails on the unpainted side…Chuck
Don’t forget to solder peices of flex track together before you curve it - this makes a better joint and the rails don’t want to spring outward when curved.
Bob Boudreau
I file off the plastic rail ties so that there is a slight concave area directly under where the rail joiner would sit. I put white glue on the underside of one end of the tie and the carefully slide it under the rail. This way the glue spread over the length of the tie as it goes into place. I usually have to set two into each join, so by working with white glue I have enough work time before the glue sets to adjust the spacing so it looks normal, and then you’re done. on to the next join.
Trevor
I use to cut the end ties for my jointers, but now use a different method that is ideal for curves.
Using a hobby knife, cut the spike heads off the end ties.
Slip the hobby knife all the way under the rail to clean any remaining burr.
Slip your joiner under the rail and connect ends.
In a curve where you have one rail that is longer than the other.
Let the long end pu***he new rail back following it under the spike heads.
When the long rail is completely in the other section, trim off adjoining spike heads at the joint on enough ties to be able and install a joiner. Makes a strong staggered joint in a curve.
REX
I use stripwood. I can cut as many as i like with a razor blade, and they slide easily under the track. Cheap and EZ. Filing and cutting plastic is WORK - to save pennies?