Let air out?

ba_fisher · 10 September 2015, 18:16

My boat says to inflate to 3.6 PSI, so I pumped it at that pressure inside my garage at around 80 degree Fahrenheit. I am planning to go out to Santa Cruz this Saturday at dawn and come back at around 1pm. The forecast is 54-84 degrees.

Do I need to worry about pumping in more air in the morning, and letting air out in the PM, especially when I am towing the boat and it's under direct sunlight? Will the tubes be much hotter than, say 100 degrees? How often do tubes break due to over inflation?

I have white Hypalon tubes.

Do you guys bring air pressure gauge and pump with you on the water?

jyasaki · 11 September 2015, 02:54

I always deflate when I put the boat on the trailer, unless I'm towing at night. Starting at home, I put enough pressure in to keep the tubes from flapping. If going through extreme temp changes, I recheck pressure every 20 degree change or so. Watch altitude changes as well. I fill once the boat hits the water, and don't worry about it again until it's out of the water.

Caveat: I have a Bravo pump wired into the boat, so pumping it up is a snap.

jky

Bigtalljv · 11 September 2015, 03:34

Yeah I got the wired pump so similar story. I travel with enough air to just keep from flopping if I know I'm going places hotter. Not sure your location or route but you could have some hot hot valleys and a (small) mountain to go over to get to Santa Cruz. (I grew up near San Jose / Los gatos border by hwy 17.

This question has been asked a million times and I've never found anybody with the physics knowledge to give a good technical answer. Have to go dig up a smart high school student

Jason

zip · 11 September 2015, 03:47

Just Googled it, and came back with a few models.
Are you guys talking about the one for $180.00?

I always keep my tubes low when not I use. I squirt a little air in from my pony scuba bottle, and top off with foot pump.

Now that I have PRVs, I might be a little less cautious.

Bigtalljv · 11 September 2015, 04:53

I have the bravo BST that only goes to 4.4 psi. Have a switched wire with a big battery cable connector http://m.summitracing.com/parts/aaf-...FVCBfgodZrEK9g

Jason

ba_fisher · 11 September 2015, 05:22

I am leaving my house at 5am so hopefully there won't be any heat issue while going to Santa Cruz. I'll bring my hand pump just in case the tubes get too soft when it hits the water. I'll make sure I let some air out on the way home. Thanks guys!

zip · 11 September 2015, 13:37

Jason, where did you purchase that pump?

jyasaki · 11 September 2015, 18:48

Lot of kite shops have them.

Do a search for Bravo Superturbo BST-12

jky

Bigtalljv · 11 September 2015, 21:06

The kite shops are usually the high pressure pumps. I'll have to dig up where I got it.

Jason

Bigtalljv · 11 September 2015, 23:05

Inflatable Kayak, Inflatable Canoe, Inflatable Boat, and Accessories by Innova Inflatable Kayaks and Canoes - for Touring, Whitewater, and Adventure.

Is the one I got.

Jason

jyasaki · 14 September 2015, 05:20

BTW, as to BA_Fisher's original question, I inflated the boat to normal traveling pressure at home at about 75 degrees (the point where the turbine section of the pump shuts off and the piston mode kicks in - no idea what the actual pressure is.) Temps hit about 93 in Petaluma, where I considered pulling over to let some air out, but didn't. Hitting the coast in sunshine and about 70 degrees, tubes still looked OK - not bouncing too much. Went from sunshine to full overcast with fog, and the tubes were flapping in the wind. Ended up pulling over to *add* air with about 60 miles to go.

jky

ba_fisher · 30 September 2015, 02:22

I am thinking of buying the Bravo Superturbo BST 12 pump as well. Does it have a pressure selector? Can you select any pressure, or are there only a fixed set of selectable pressures?

How reliable has it been for you guys?

Also, how would you fill up the chambers? Do you first full each up to half inflated, and then each up to fully inflated? If so, what pressure do you choose for the 'half inflated'?

The max pressure for my boat is 3.6 psi.

Thanks!

zip · 30 September 2015, 05:40

Ba,

Yes, it has a rotary dial pressure selector.

I have only had mine a couple of weeks, but it seems to work ok. Not sure how accurate the dial is. I will have to check with a gauge.

When I first air up I set gauge to 1.5, and fill all chambers. I then come back for a second round at max, which I believe is around four. Even at max air setting, I don't feel I'm getting max air though. Valves on tubes need to be open, or pump shuts off immediately. When valves are open, and pump shuts off, you lose some air closing the valves. With the foot pump, you can fill air without valves being in full open position.
This boat is new to me, and I have one chamber that goes flat in around an hour. The rest of the chambers appear to "weep", and need to be pumped up every day. Not sure if the weepage is normal, but the electric pump makes it a little less of a pain.
The pump will not reach the front chamber due to the power cord length, so I use jumper cables. I intend to make some modification to that in the future.

Bigtalljv · 30 September 2015, 07:41

Ive found the pump dial to be a little low, 2.5psi is less. Get a gauge as well to get it set right. My tubes hold air ok so I just fill them to pressure in one shot.

Jason

zip · 30 September 2015, 13:33

Jason,

What air pressure do you suggest, and what kind of gauge do you recommend?
When you installed your male/female quick disconnects, did you extend the wire too?

mick · 30 September 2015, 16:42

Don't you guys have pressure relief valves

Bigtalljv · 30 September 2015, 17:50

Not me. Tubes are too old I guess. Military didn't do that back then I guess.

I used this gauge, it's for leafield valves, http://rivergear.com/raft-inflatable...-leafield.html

Jason

jyasaki · 01 October 2015, 16:07

Quote:

Originally Posted by mick

Don't you guys have pressure relief valves

I bought them; have yet to install (or have them installed.)

jky