Duncan asks: I enjoyed the Doncaster photos but I am puzzled re the comment about Sundeala. I have pondered using it, several model railway 'tomes' (not magazines) espouse it as the best.
So what's to do, please?
While I'm sure Sundeala has it's uses, as far as I am concerned, they don't involve model railways. Let me explain why with a story.
This is the Leamington & Warwick MRS N gauge layout "Meacham". Strictly speaking, it's Meacham Mark 2 though. It looks just like Meacham Mark 1, but with a big difference - proper baseboards.
Mark 1 was built on boards that made use of a insulation board top, a cheaper, generic form of Sundeala. After a few months the tops started to sag until the trackwork became a series of humps and dips. Hardly ideal for N gauge. Something had to be done.
At first there was bodgery with extra bits of wood stuffed underneath but this didn't fix the problem. The only solution was to strip everything off, build non-sagging boards, and put it back. Not a quick or simple job, but well worth it in the long term.
When used for model railway baseboard, the Sundeala website, recommends bracing the boards every 18 inches. To my mind, that's not enough. I'd want every 18cm and possibly closer.
When I ask why people consider the stuff, the answer is always the same - It takes track pins easily - although my friend Colin points out that if they go in easily, they come out just as well...
So you will use an unstable material for the most important job on your layout just to save the effort of drilling a few pilot holes and buying a small hammer?