On a previous layout, I used Peco SL14 into Peco flex track & into Canite which is a type of Sundalea board & only pre-drilled the sleepers on points. Had no problems pushing the pins into flex track sleepers.
The Canite/Sundalea of 12mm sat on MDF of 12mm to give it a good base to stop it sagging. After pinning every 6 inches or so ( closer together in tunnels), I then painted the whole lot with a dark brown acrylic like Mission Brown. Ballasting with diluted PVA was done in 12" lots, left to dry, then came back in about one week to fill in the gaps.
Never had any problems with warping. Any joins in the canite/sundalea had masking tape over them to stop ballst falling into the gap.
Current layout is track straight onto 12MM MDF - no cork - & in this case, I use a Dremel type drill to pre-drill into MDF by about 5 mm & tap the pin with. Again no problems.
To see a couple of pix of one of my stations see
http://www.nmra.org.au/Layout_Tours/Ron_Solly/index.html
Ron
The Canite/Sundalea of 12mm sat on MDF of 12mm to give it a good base to stop it sagging. After pinning every 6 inches or so ( closer together in tunnels), I then painted the whole lot with a dark brown acrylic like Mission Brown. Ballasting with diluted PVA was done in 12" lots, left to dry, then came back in about one week to fill in the gaps.
Never had any problems with warping. Any joins in the canite/sundalea had masking tape over them to stop ballst falling into the gap.
Current layout is track straight onto 12MM MDF - no cork - & in this case, I use a Dremel type drill to pre-drill into MDF by about 5 mm & tap the pin with. Again no problems.
To see a couple of pix of one of my stations see
http://www.nmra.org.au/Layout_Tours/Ron_Solly/index.html
Ron
