A visit to Suva, the capital of Fiji, has been on our minds for a while, for some more industrial supplies. For example: Since French Polynesia, we have not been able to fill our two 5lb CO2 tanks, from which we make our own sparkling water. We do have eight 400gr Sodastream-type cylinders that can be filled locally, or at least by sending them to Suva, but that is not very cost effective (still better than buying sparkling water in small cans or plastic bottles).
This part of the globe uses Australian standards for gas fittings and our US tanks have different tank fittings, which the local industrial gas suppliers cannot, or refuse to, fill.
There is a way though. We had not done this before, but one can unscrew the valve on top of the tank, and fill the tank with a precise weight of "dry-ice", which is 'just' frozen CO2. That dry-ice comes in an insulated box from the factory where it is produced and starts subliming immediately (turning to vapor from a solid state, skipping the liquid state).
They have such a dry-ice producing machine at Oceania Gas in Lami, a few minutes taxi ride from the RSYC. We prepped as good as we can: Unscrewed the tank valves, had funnels of different sizes handy, spoons to shovel the dry-ice. Yes we also prepared some goggles, leather gloves. We had weighed and marked the tanks to know how much we can fill, by weight. The Tare-weight embossed in the tanks includes the valve, and we are filling without the valve, so need measure our own Tare-weight and calculate the "full" (gross) weight from there. A digital scale with a range of 10kg worked well, but one has to do some mental averaging since the slightly rocking boat causes fluctuating numbers.
We had called ahead to Oceania Gas, then took the taxi to the sales office in Lami. Once we showed up there and placed the order, we then had to wait for about an hour for the order to be fulfilled. There is a Yacht Shop in walking distance one can spend time and money at. To be quick on the return trip, we got a taxi back to the sales office of Oceania, paid, then got directed around the corner to pick up the dry-ice box. First surprise, the box was more wide than tall and the lid didn't want to stay on. It was not plastic wrapped as originally promised, so we double bagged it in shopping bags. Driving back, we kept the taxi's windows open, the pellets being somewhat agitated in the box trying to sizzle and escape. The dinghy ride to the boat didn't help to not waste dry ice.
Back at the boat, we attempted to fill the pellets into the tanks. They certainly didn't want to slide down a funnel that fit inside the throat of the tank. Using a larger funnel that needed to be held on top of the throat worked better. Endlessly slow we fed the tanks with spoons, we will have a better scoop next time.
Pellets escaped and sizzled on the hot teak, even touched the skin. We didn't get any burns, avoiding prolonged exposure.
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| Don't get touched by the pellets. The tank starts freezing up on the outside and one can compare fill levels |
We filled by weight, checking that often while filling the other tank. Overfilling would cause over-pressure, which then would cause a safety-burst-disc in the valve to release all CO2.
Handling the freezing tanks felt more dangerous than dealing with the CO2 pellets. Putting on the valves and tightening them, holding the tank with a strap-wrench, needed good gloves and towels.
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| Freezing |
We left the tanks there warming up for an extra day and kept checking the weight, to make sure no CO2 escapes. Next time we bring extra o-rings for the tank valves (Buna 216).
We bought the minimum of dry ice (5kg), which is 11 US lbs. In the end, one tank was full (5 lbs) and the second one barely had 4lbs in it, so we wasted >= 2 lbs of CO2 in the transport and process. Next time we will do better.
A full CO2 tank keeps us bubbly for 2-3 months, and when both are empty, we may have to rent a car, bring the equipment, and do that filling under a shade tree.
All this is a bit TMI for most, but targeted to a couple boats wanting to do the same thing.
Bubbly Cheers!
