Mystery has often surrounded his request for a large table in his dressing room, but he has decided to come clean and admit that he uses it to make miniature buildings for his model train set.
And according to US magazine Model Railroader, the 66-year-old insists on staying sober so that he can concentrate, and he even has a fan so that the glue fumes don't affect his voice.
He told the publication, 'I can't build after a couple of glasses of wine - the results are never good.
He explained that a good model builder has '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,' he added.
The star confided that he can spend up to four hours a day indulging in his passion, and that he has a 1,500 sq ft (139 sq m) model train layout on the third floor of his Beverly Hills home.