January 24, 2007
Leaky Tubes?
Are My Tubes Leaking?
For departments using RIBs in colder climates during the winter, this is a common question and concern. The answer nearly every time is NO.
Because the tubes are air filled, they are susceptible to temperature change. Changing temperatures cause the air pressure inside the tube to fluctuate. The tubes become harder as the air expands on hot days and on colder days the air contracts making the tubes softer.
This is extremely evident during the winter for fire departments who store their boats inside the station until needed. Many first time RIB users panic when they move the boat from the 68 degree station to the outside where it’s 35 degrees. Within minutes the air inside the tube contracts and the tubes soften.
To minimize this effect, I recommend putting the boat outside in the cold for a half hour and then pump the tube up as much as you can with the foot pump. Then bring the boat back in. The tubes will become hard once inside, but hopefully the next time you go out, the tube change won’t be as extreme.
Similarly, during the summer, you could be out on the RIB in the afternoon and all seems fine until the next morning when you go out and you notice the tubes are soft. What happened? Much like at the fire station, in the afternoon it could have been 90 degrees and the next morning it was only 70. If you notice the tubes are softer in the morning - be happy, you're lucky. The pressure relief valves worked the day before as the air pressure in the tube expanded dangerously in the heat, the valves worked - releasing some of the air to maintain a safe operating pressure. This protects the tube, but when the air temperature drops as the sun goes down there’s less air in the tube and thus the tube becomes softer. When this happens, be thankful, because the alternative would be much worse. All you need to do is simply add a little more air with the foot pump. This rarely occurs, but it’s not unusual to have this happen once or twice during the summer in New England.
Bottom line, if you suspect your tube is losing air and all the chambers seem to be losing the same amount simultaneously, then you’re very safe in assuming your tubes aren’t leaking. They’re just adjusting to their surroundings.
Posted by ribcraftusa at January 24, 2007 04:54 PM
Comments
If you fill your tubes with helium you will not have this problem, and your rib will really fly!!!
Posted by: Bob Jones at January 25, 2007 08:55 AM
What about putting Nitrogen in the tubes? I've heard of folks inflating car tires with the gas to prevent pressure loss in cold temperatures.
Posted by: Justin at February 8, 2007 11:49 AM
I heard the same thing about Nitrogen. I bet it would keep the tubes a bit firmer in colder temperatures. The Question is how much firmer vs the pain and expense in procuring Nitrogen.
Posted by: tibs at February 16, 2007 04:47 PM
