Inflatables blowing up from heat (air) expansion.

[susp3nd]

Has anybody ever heard of deflating their inflatable for fear of their inflatable bursting from over pressure?

Just seems possible but not much information on it that I could find.

 

[Sea Rider]

Re: Inflatables blowing up from heat (air) expansion.

You should deflate inflatables if leaving them on hot surfaces as concrete floors, hot sand and out of the water for extended time or when transporting a inflated sib from sea level use to high altitude. No problem with inflatables that have pressure relief valves on tubes. Get yourself a pressure gauge to be on the safe side. Your inflatable should have a user's manual, that information should be written inside.

Happy Boating

 

[susp3nd]

Re: Inflatables blowing up from heat (air) expansion.

sooo if i fill to correct pressure before i get in the water i have nothing to worry about as long as the boat is in the water correct. Once removed it is a different story.

I live up here in Reno and I go to the outlying lakes a lot. The boat will be deflated when i pack it up into the car.

 

[nobrainsd]

Re: Inflatables blowing up from heat (air) expansion.

The answer to your question all depends on the temperature differential. If you fill the boat to full pressure on a cool morning and go out on a relatively warm lake on a hot sunny day you can get excessive pressure as the volume of air in the boat heats up and expands. When I'm in Mexico the mornings are really cold and even the not hot water won't keep the tubes from heating up midday. You can't assume the water will keep the tubes cool. I just check the tube pressure every once in a while as the conditions change. A lot of the time I'm checking because it's cold and tube pressure is too low for optimal operation. What you don't want to do is leave your topped off boat sitting in the hot sun for extended periods of time. I bleed a little air out if the situation warrants.

Yes, I have seen a boat blow a seam from baking in the sun. My zodiac sits on the trailer with the tube pressure a little low to leave room for fluctuations. It's worth paying attention to.

 

[susp3nd]

Re: Inflatables blowing up from heat (air) expansion.

what gauge would you get....the boat has boston valves?

Thanks

NM google search is a great tool. i found one. thanks!

 

[likalar]

Re: Inflatables blowing up from heat (air) expansion.

Yes, I have seen a boat blow a seam from baking in the sun. .......It's worth paying attention to.

Maybe you know me? ;-) My black Zodiac exploded (LOUD bang!) many years ago. We had launched on the Delta near Stockton early in the morning (maybe 65 degrees?). By 2 pm, we were tied to a friend's houseboat, finishing lunch (maybe 100 degrees?). An entire 2' long factory seam on a forward section blew wide open. Ouch! My fault for not paying attention.

Larry

 

[Sea Rider]

Re: Inflatables blowing up from heat (air) expansion.

Yes, it's all about exterior environment heat conditions, water temperature, atmospheric pressure, luckily for us, we don't have excesive heat/sun and our water is cold, compensates very well overinflation issues when sib is on water and inflated to a pre determined safe pressure. Old dark sibs are prone to blast seams because glue is dry out specially when leaving them unattended in sunny environments.

Happy Boating

 

[susp3nd]

Re: Inflatables blowing up from heat (air) expansion.

What do you do when you blow a seam? Is the boat now worthless? It seems to me that if it can be fixed it would be a costly repair.

 

[nobrainsd]

Re: Inflatables blowing up from heat (air) expansion.

Always better to avoid a repair! So pressure testing your tubes is probably not a good regular practice. They do withstand a lot of abuse! The whole pressure thing isn't that hard to deal with. You just want to avoid the extremes, like pumping up the boat fully on a cold foggy morning and then leaving it sit midday in the hot sun on your trailer in a parking lot. I always bleed a little air out when the boat is going to sit on the trailer. It is worth the effort to top off when I need it again.

We do the same with professional river rafts. They get pumped all the way for stability, but either get parked in the shade or doused with water occasionally during lunch. It's just prudent.

 

[Howard Sterndrive]

Re: Inflatables blowing up from heat (air) expansion.

I wonder why relief valves aren't more common.
The only inflatable I ever had with reliefs was a Sevylor TX290.

All I had to do was spin off 2 caps when I parked it, and the reliefs were free to let air go if needed... peace of mind...I loved that setup

I left the caps off when I was inflating - I could make the tubes rock hard without fear of popping one

 

[likalar]

Re: Inflatables blowing up from heat (air) expansion.

What do you do when you blow a seam? Is the boat now worthless? It seems to me that if it can be fixed it would be a costly repair.

In my case, the boat was fairly new, so I took it to a dealer, who called in his freelance inflatable repair specialist. The guy knew his stuff, did an expert repair, and I could not tell the seam had ever been split open. If I remember correctly, it was $200+, several years ago, so would cost much more now. Worth it, IMO.

Larry

 

[Chris in Indiana]

Re: Inflatables blowing up from heat (air) expansion.

I always inflate my boats on land, launch and then top off in the water after 5 minutes or so. The cold water drops the pressure quite a bit in my experience. However I'm always mindful of temp changes and the sun and give the boat a "feel" every now and then. You get used to what over pressure feels like once you have a gauge and spend time fiddling with it. I rarely use the gauge anymore but I've had the boat forever. I will say that when I pull up on the beach and drag the boat up to sit for a while I usually let a little pressure off.

I would love to see a pop-off pressure protection device but as a pneumatics engineer I know why they don't exist. For a while it was a pet project of mine. Low pressure is a very difficult and expensive thing to meter and control which is why a car tire gauge costs a few bucks but an inflatable boat one runs about $50, give or take. A cheap low pressure device that's actually reliable would be quite an accomplishment and you could make a lot of money if you come up with something. Most valves of any kind have a specified crack pressure with a +/- 15 psi rating. An inflatable boat pop-off would need a spec in the +/- 0.1 psi range that could handle humidity, sand and all the other gunk that gets on an inflatable.

 

[Sea Rider]

Re: Inflatables blowing up from heat (air) expansion.

I would love to see a pop-off pressure protection device but as a pneumatics engineer I know why they don't exist. For a while it was a pet project of mine. Low pressure is a very difficult and expensive thing to meter and control which is why a car tire gauge costs a few bucks but an inflatable boat one runs about $50, give or take. A cheap low pressure device that's actually reliable would be quite an accomplishment and you could make a lot of money if you come up with something. Most valves of any kind have a specified crack pressure with a +/- 15 psi rating. An inflatable boat pop-off would need a spec in the +/- 0.1 psi range that could handle humidity, sand and all the other gunk that gets on an inflatable.

An Italian manufacturer has come with a pressure relief valve that screws on top Halkey Roberts Valve, you can attach a pump to side of system to inflate sib, once 3.3 psi is reached will open spring coil to release overinflation, works too while baoating under excesive sun. Will need one for each tube. You can find low pressure gauges that ranges from $ 10 to $ 35, that reads from 08 to 15 PSI. The lowest reading gauge dial the better if you will be just inflating tubes to 3.0/3.5 PSI.

Happy Boating

 

[dobbs571]

Re: Inflatables blowing up from heat (air) expansion.

On my Fish Hunter 360 I have to ajust the pressuor a lot . you can tell if you set in the sun for an hr even on the water it gets tight and I let some out if you pull up in the shade for a while I have to add air most of the time . I put my hand on the top of the tubes and can kind of tell vinyl or PVC will strech alot when hot it took me a summer of floating to not get scared of the seams poping now dosent bother me much if I pull up on a beach for 1/2 an hr I know to let some air out I got a dubble action hand pump I carry with me only takes maybe 10 or so pumps to get it back to where it needs to be. And throw a wet towl on the tubes helps a lot too

 

[RickVS]

Re: Inflatables blowing up from heat (air) expansion.

My Sevylor Caravelle 12' has a gauge built in, but I never pay any attention to it. I just leave my boat underinflated to not have to worry about it. This is a leisure boat, so laying down straddling the sides is no biggy. Ply the Boat Boot keeps it pretty stiff anyway. I guess if you have a FH or another boat that has to be stiff for you to stand up on, I guess you'd need to keep it fully inflated and keep aware.

 

[Sea Rider]

Re: Inflatables blowing up from heat (air) expansion.

I had a Sevylor K-86 and used to overinflate it before launching to sea to have more rigidity, that is, slightly pass the max built in gauge recommended pressure, final short story, got caught by a wave and the lateral tube exploded next to the side seam Sevylor's have 2 pieces fabric welded seams, so watch out for overinflation issues during palin summer or bang

Happy Boating

 

[riverandocean]

Re: Inflatables blowing up from heat (air) expansion.

My Zodiac Grand Raid has those fancy intercommunicating valves which have over-pressure release springs in them.... but the keel valve does not.... have seen a Grand Raid with the keel tube popped.....

Like everyone has already posted..... let off a little air if taking the boat out of the water.... or temperatures are high.

Have fun out there

 

[Sea Rider]

Re: Inflatables blowing up from heat (air) expansion.

The only way to pop a keel is when keel has some form of fabric deterioration caused mostly by constat friction against upper wooden/alum pannel floors at some part of the keel, usually at first bow pannel where keel angle is formed.

Happy Boating