Butanone is a serious solvent so shouldn't let the chairs fall off the sleepers. Perhaps you didnt have them pressed down enough or for long enough. As far as holding the chairs to the rails, these shouldn't be glued at all as they grip the rails but need to move to deal with heat expansion, and obviously with a slide chair only one rail is gripped, the other is free floating

I've just been building my first C&L turnout in EM - B6 like yours. I build directly onto the board, so don't have the problem of the slide chairs falling off!

For most of the chairs I've been using the Exactoscale variety - the C&L point kits only seem to provide standard sized chairs - near the V, I used some of Exactoscale's bridge chairs - they fit much better as you get closer to the common crossing. I've also been trying out some of Exactoscale's insulating fishplates - I had brass droppers to supply power to the rails close to each end of every rail (big believer in redundancy!), and should probably have made the holes in the baseboard a bit larger to give me more wiggle room when putting the rails into place as they're a bit tight and it made mounting the fishplates quite fiddly. They do ensure that rail sections are nicely lined up. As far as the fishplates go, make sure the wooden chocks in the chairs either side point away from the fishplate (as they should), or there's not room for them - I miscalculated on a couple of occasions!

As far as pushing the chairs onto the rail go, it can be a bit fiddly and hard on the fingertips, but is easier if you file the bottom bit of the bullhead to a taper at one end. I've been trimming my rails with a razor saw and tidying up the ends with a fine file.

Good comments, thank you!

I am hoping that gluing the chairs to the rails will work as I shall have some movement for temperature expansion/shrinkage between the baseboard and the sleepers by using rubber-type cement.  And (my existing) soldered track has no room for movement at all between chair and rail!

Yes, filing down the end of the bullhead rail is essential.  My problem was more with holding the chair between finger and thumb!

I think building the points directly onto the baseboard is the better way to go, that is, if you can.  If I decide to lay more C&L track that is what I would do.

Butanone is a serious solvent so shouldn't let the chairs fall off the sleepers. Perhaps you didnt have them pressed down enough or for long enough.

Sorry to miss this in my previous comment.  The Butanone works fine, it is the lack of adhesion between chair and rail which was/is my problem.