07-20-2009, 12:06 PM
[cool][#0000ff]First, it really does not matter what kind of bladder you have. Basic physics says that air expands when heated and contracts when cooled.[/#0000ff]
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[#0000ff]You will notice contraction, after airing up your craft under several conditions:[/#0000ff]
[#0000ff]1. When you take the craft out of a warm vehicle and place it in colder outside air or on water colder than the air temp.[/#0000ff]
[#0000ff]2. During the day, if the sun becomes obscured by clouds or starts going down late in the day. The radiant heat of direct sunlight keeps the tube cover tight. But, as soon as that heat source is gone, the air will shrink a bit.[/#0000ff]
[#0000ff]3. If a cold storm blows in. A bit of moisture on the cover evaporates and cools the tube. That can happen fast in a heavy cold rain.[/#0000ff]
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[#0000ff]If you start out with the air chambers firmed up well, a slight air contraction should be no problem. But, if your cover becomes noticeably saggy, you should either add some air from the spare pump you carry or head for shore. A few pumps should restore the firmness for the rest of your trip. If it still loses pressure you should look for a pinhole leak or a valve problem.[/#0000ff]
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[#0000ff]On the other side of the coin, your tube will swell as the daytime temperatures rise...especially when the hot sun is beating down on it. Overinflated bladders will split, so you should check them for firmness as the day gets hotter. Just a quick bleedoff of excess pressure will not affect your ride but can keep you from having to walk back to shore if your air chamber splits out.[/#0000ff]
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[#0000ff]Even more important is to bleed off some air as soon as you get back in to leave. If the air chamber is already over-filled due to the hot sun, it will get even worse once you pull your craft up out of the water. That is good advice both for the main tube and for inflated seats too. [/#0000ff]
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[#0000ff][/#0000ff]
[#0000ff]You will notice contraction, after airing up your craft under several conditions:[/#0000ff]
[#0000ff]1. When you take the craft out of a warm vehicle and place it in colder outside air or on water colder than the air temp.[/#0000ff]
[#0000ff]2. During the day, if the sun becomes obscured by clouds or starts going down late in the day. The radiant heat of direct sunlight keeps the tube cover tight. But, as soon as that heat source is gone, the air will shrink a bit.[/#0000ff]
[#0000ff]3. If a cold storm blows in. A bit of moisture on the cover evaporates and cools the tube. That can happen fast in a heavy cold rain.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]If you start out with the air chambers firmed up well, a slight air contraction should be no problem. But, if your cover becomes noticeably saggy, you should either add some air from the spare pump you carry or head for shore. A few pumps should restore the firmness for the rest of your trip. If it still loses pressure you should look for a pinhole leak or a valve problem.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]On the other side of the coin, your tube will swell as the daytime temperatures rise...especially when the hot sun is beating down on it. Overinflated bladders will split, so you should check them for firmness as the day gets hotter. Just a quick bleedoff of excess pressure will not affect your ride but can keep you from having to walk back to shore if your air chamber splits out.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]Even more important is to bleed off some air as soon as you get back in to leave. If the air chamber is already over-filled due to the hot sun, it will get even worse once you pull your craft up out of the water. That is good advice both for the main tube and for inflated seats too. [/#0000ff]
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