Owners Antony Arena, Lorenzo Focarile, Dean Brown and Sam Carlini have battled with the weather to get the finishing touches on the Melbourne Building venue, which is a Cuban-themed tropical-style bar.

"There was an airline that popped up during prohibition that would fly Americans down to Cuba for the weekend, basically to drink. That flight got a nickname and it was called the Highball Express," said Arena.

"When you got on board they'd serve you cocktails in highball glasses, so people would just have a few on the way down."

"Amongst the well-to-do it would be a bit of a, 'Wink wink nudge nudge what are you doing this weekend?' 'Oh I'm catching the highball express.'"

There's also personalities from the era scattered throughout the bar, from a mural of Pappy Valiente, the man who would meet visitors on arrival in Cuba, and Peggy the drinks trolley, named after air hostesses of the time.

Unlike the owners' other venue Molly, which is all about whisky, Highball Express will be all about rum – with more than 300 varieties on offer.

"We have all kinds of different spiced rums and overproofed rums and some really interesting and unique stuff that people in Canberra probably haven't seen before or had access to before."

The highlight is 12 custom-built oak barrels housing rum cocktails.

"We'll be barrel-ageing cocktails, so we'll have 12 different ones running at a time. When you barrel age cocktails they do actually draw a lot of oak flavour and sweeten up considerably.

"We've got decent sized barrels, about 50 or 60 litres, so they need about a month in the barrel to really start to extract the oak flavour, so we're loading them up now ready for opening."

And you don't just have to enjoy Highball's rum at the bar – they have an off license and sell their speciality bottled rum punches for you to take home, wax sealed shut.

Just in time for summer, the venue will have a laid-back tropical feel, hard to find in Canberra, with lots of natural sunlight.

In the refurb of the space, which sits above Smith's Alternative, they've removed some glass windows, creating a large balcony and restoring the external facade to its original condition.

"It has a really nice outlook, north facing, and it will get some sun during the day and at night you'll get a beautiful sunset over Black Mountain."

The fitout also pays tribute to the original Cuban flights, with silver ceiling fans that echo aeroplane propellers and a sleek 12m bar top. The bar will open from 2pm or 3pm, and will continue well into the night, with room for a dancefloor.

"The music will be very sort of chilled, South American reggae sort of vibe right through to Latino hip hop, and from time to time we'll have a live band or DJ," he said.

"People in their mid twenties and above say there's nowhere in Canberra to go and dance so we want to facilitate that but for it to be real fun tropical party atmosphere.

The trio, along with bar manager Sam Carlini, has been helped with getting up and running thanks to the ACT Government's Access Canberra initiative.

"Everything they said they were going to do, they did. Who knows what date we'd be talking about opening if not for that", said Brown.

And they have another bar in the works. "We've started planning on the next bar. If all goes ahead, it will be opening early next year," said Arena.

See highballexpress.com.au.