The 66-year-old singer said he even asks for a large table in his dressing room when he is touring so he can continue with the train set.
However he added that a fan has to be kept on so that the fumes from the glue don't go down his throat.
Speaking to Model Railroader magazine, he said: "You have to have an eye for proportion - a sense of what fits naturally - right down to the placement of the advertising signs.
"When I find myself focusing so intently on a model that it ceases to be fun, it's time to walk away, have a cup of tea and come back to it later."
However he might not have so much time soon when his wife Penny Lancaster gives birth to their second child next month.