Some help I hope

Mitch,as I don't know what materials you are using for the mold(I use Dow-Corning RTV 3420)or resin(I use Alumilite) my experience may be worthless to you but I've had great success casting track.Obiviously it requires a double-sided mold(with RTV a film of vaseline acts as the release for both sides).Once I have my mold(make sure you have line up points)I drill a small hole in the top of the guide tooth(teeth)to let the air out.I then mix my resin and using a toothpic add a few drops to each side and push it into all the tiny cracks and crevices(especially the guide teeth). Once I'm satisfied on that score I fill both sides of the mold and push them together.Messy,and not my normal way with two-sided molds, but because track is so tiny and the difficulty of getting the resin to flow into it,it works for me.Once I have a suffient number of track(usually 6 to 10) I join them to make runs and another mold,leaving enough to go around the sprocket and idler.The length of the runs depends on the vehicle and if you require sag on top.As I said,this has worked for me numerous times and I hope I've been some help.John