Totally agree with Phoebe Vet, it's not worth taking any risks with any electronic devices. They need to have free flowing air. If you encase them in foam and not allow a good circulation of air around them then you will be risking overheating and problems. I have built slide out drawers beneath my layout for all my NCE Switch8's, transformers, DCC and various other electronics. This not only makes access very easy , it also ensures air is free flowing.
Hope this helps.
Heat is the deadly enemy of solid state electronic devices. Notice the vents and/or heat sinks on pretty much everything electronic that you own. I do not recommend surounding any electronic device with foam insulation.
Dave
Lackawanna Route of the Phoebe Snow
I have a construction foam base for my layout with a 1" channel along all four sides (as David Popp has shown on layouts like the Red Oak project - http://mrv.trains.com/videos/project-layouts/2015/01/video-building-the-3-x-7-red-oak-model-railroad-episode-3). I'd like to make an area for an NCE Snap-It stationary decoder in the channel but I think I'm going to need to hollow out a little foam before it will fit. Have you ever had issues with components in foam recesses overheating, damaging the foam, or catching fire? If any are needed, what precautions should I take?