The event offers a variety of activities for kids of all ages and abilities, with a heavy emphasis on Thomas-themed displays this year.

"We will have model railways running, items for sale, a repair stall for Thomas toys, and even a display where children can take a turn at driving Thomas," museum chairman Peter Meddows said.

"Also for the young ones, there will be a massed display of teddy bears, while older age groups may enjoy the radio-controlled aircraft or the fire safety display.

"Miniature trains to ride and vintage farm machines can be found in other parts of the site, and of course there will be unlimited steam train rides."

The museum's new informational signage will be on display for the first time this weekend.

Funded by the NSW Government Community Building Partnership program, the signs will be unveiled by Cessnock MP Clayton Barr on Saturday.

Family Fun Fest will run Saturday and Sunday, with gates open from 9.30am each day.

After Family Fun Fest concludes, the museum will be open for the first three Sundays in October, with the regular displays.

Hot and cold snacks are available or families may picnic in the museum grounds.

Admission to the museum is $16.50 adults, $11 concession, $7.50 children aged 5-15 and children under five free.