SIB air pressure Top Up in cold water.

[cat10]

Hi folks, I am new to SIB,s and just wondered if it is the norm to top up the air pressure in the tubes and air floor when the boat is in cold water.

I appreciate the the air pressure drops when the boat is on cold water but just wondered how you guys top it up. I am not to sure about using the foot pump on the air floor in case it damages it.

Is a stirrup pump a better idea ?

[jeffstevens763@g]

Personally I pump mine up to pressure at the beginning of the season and don't touch it unless it gets into the high twenties centigrade when I let a bit of air out I just forget now but doing the maths I think ten degree rise in temp increases pressure by six percent which works in reverse too if you have to top up pump on the floor will be ok larger area better than the stirrup pump

[Max...]

I check mine an hour or so before each launch and pump the floor to just under 12psi rather than the 11.4 (BAT so floor is critical for best performance)- for the tubes I'll go maybe 1/2 psi over. If you leave it out in the sun though you should check and let some out if it gets too high.

Trying to do it in the boat with a manual pump is not something I'd try! Maybe the tubes would be doable but forget the floor at that pressure.

[Fenlander]

If we are on holiday with the SIB on the water for a few days then there is the luxury of checking it after a while on the water to top up and then checking every couple of days after that. Also it's no trouble in that circumstance to carry the elec pump and small battery to it if a top up needed. When it is on holiday hauled out to a cottage garden or similar at the end of each trip or on a daily outing set up from the car just for that trip like Max I have judged the slight over-pressure needed to compensate for it cooling once in the water.

Of course in the holiday cottage situation I let a bit out at the end of the trip in case we don't use it the next day when it might be sunny.