Significant Temperature Change & Trailering

[TheTechChik]

A friends brother-in-law is going to tow my 19' Apex from Michigan to Florida (approx 1200 miles) for me next week.

The potential problem is...

The tubes were fairly firm at 75 degrees Fahrenheit a couple of weeks ago. Now the temperature has dropped to around 40 degrees Fahrenheit and they are really soft. In fact they sag quite a bit and even bounce around when the trailer is on a rough road.

If I fill the tubes up now at the colder temperature, do I risk over-pressure and a rupture when he gets to the warmer climates in the south?

If I leave the tubes soft, can the wind and/or bouncing around on the highway do any damage to them?

I just bought this boat recently and have absolutely NO experience whatsoever with RIBs. Additionally, there is hardly anyone around our area that knows anything about them either. Any advice would be greatly appreciated. :-)

Amanda

[Biggles]

Hi and welcome to RIBNET.

Although I'm not familiar with the area your going to be travelling I think the solution is going to be quite simple. Take an air pump with you and make sure the tubes are reasonably firm prior to setting off. Then take a stop every hundred miles or so and let a little air out at each stop. If you let too much air out at any point you'll always have the pump with you to top up to a reasonable level.

Hope this is of some help.

[Hightower]

Providing the tubes aren't nearly deflated and that they roughly retain their shape, then the answer is, it will be OK to travel with softer tubes.

If you want to entrust your brother to checking the tube pressure on the journey down South, then I would pump untill firm at the beginning of the trip and deflate the tubes as you move South to warmer parts.

Wish I was going to Florida!

[Nick Hearne]

Dose the Apex have pressure relief valves fitted?
If so just pump it up & they will do the job for you!!

[TheTechChik]

If I were pulling the boat, I would definitely pump them up and make adjustments as I travel. The problem is, I don't know if I can trust him to pay attention or not since I don't really know him very well.

As far as the "pressure relief valves", I don't know and I haven't been able to find anyone near me that has experience with RIBs. Is there any way for me to identify them? Can someone post pictures of both types for comparison? Is there anyone on the board from the Metro Detroit area that knows of a local shop with RIB experience?

P.S. If it turns out that I don't have "pressure relief valves", can it be refitted with them?

Thanks for the help!

Amanda

[Hightower]

You can get pressure relief valves fitted, not sure if you can get retro fit ones a that replace the existing valve mechanism, but definatly can have them fitted as a whole unit.

As for the tubes Amanda, leave them soft and entrust in the power of Hyperlon or PVC.

If you're that worried, deflate them completly and tape or strap the excess to the hull so it doesn't flap around. Should make the Gas milage better too.

[Dave Berry]

Not sure if the shop is still around, but there used to be a place around Detroit, maybe Ann Arbor, that was called "Hurricane Inflatable Boat Center" or something like that. I think the fellow's name who ran it was Bruce Wagner. I met him a few times years ago when he used to live in Toronto.

Most Apex tubes I have seen are either white or light grey hypalon so the increase in tube air pressure will be a little less pronounced as the boat travels south. I would suggest inflating the tubes in Michigan until they are "almost firm" so that they don't flex too much on the highway at cool temperatures. By the time the boat reaches Florida the tubes will have become pressurized, but not too the point of blowing a seam IMO.

I don't think Apex tubes are supplied with pressure relief valves as standard items. They can be added. Maybe Bruce can help you out if he is still around.

[jyasaki]

My Polaris seems to be pretty sensitive to temp changes. So much so that I routinely soften them when pulling the boat from the water (going from 50 F water to direct sunlight.) I find that even worse is elevation changes (or worse yet, elevation changes in hot weather.) Trailering from the Bay Area to Lake Tahoe is a never ending cycle of pulling over, adding or removing air, and getting back on the road.

I doubt being somewhat underinflated will hurt anything; my tubes have been bouncing while trailering for 2 years, and no apparent problems are showing up. I actually use the bounce to gauge how tight the tubes are getting when going from coastal (cool temps) to inland valley (higher temps.) When they stop bouncing, I relieve pressure a bit more.

I sourced some Leafield A6 (I think it was) pressure relief valves from a place called Man of Rubber (a shop whose name would fit in quite nicely in San Francisco); I had originally planned on doing the installation, but it appears I'll have to have them patched in, so it will probably be done professionally when I get a break in the diving.

jky

[Hightower]

When you think about the pounding the tubes get whilst in the water, a little bit of bouncing on a trailer isn't going to hurt them at all.

[Gordon McMath]

Hi Amanda,have a look at your tubes & see if there are two round plastic caps on each tube compartment,if there are two then one of them should the pressure relief valve,if you have any doubts then get yourself an electric inflator which can be reversed to suck the air out of the tubes,you will be suprised at just how hard this will suck in the tubes to the lip that they are mounted on,I am in Florida until Dec 11th,if you need any help then give me a call on 407 704 0199.Best of luck & welcome to ribnet.Gordon.

[Locozodiac]

Hola Amanda

Seems you are having big trouble with inflation issues, will give the best remedy for it. Some previous data: Most inflatables dinghies, ribs, etc made of PVC or Hypalon have a MAX working pressure of 3.5 PSI or 0.25 Bar. It's virtually impossible that by finger touch you can obtain this reading, if you haven’t inflated a tube with a pressure manometer previously to confirm this reading by finger touch, will need a very sensitive finger to do so. Is like inflating your car tires at sight or finger touch, will have 4 different readings.

With ribs you cannot have poor boating performance when cruising with under inflates tubes as in normal inflatables dinghies because of the hard hull difference, tubes on this boat type are mere aestethic because they almost hardly touch the water, and if they do only a very small portion. So cruising with under or over inflated tubes won’t slow nor speed the boat as in traditional inflatables.

If you want to have all compartments inflated to the correct pressure in winter and summer get yourself a good pressure manometer that reads from 0 to 14 PSI or 1.0 Bar. About your inquiry if you are traveling from cold to heat, inflate all chambers to 2.0 PSI, at this reading you will feel the material hard at finger touch, while traveling the sun will do the rest inflating it to near 3.0 PSI or a little more. Don't you ever inflate to working pressure at sea level and take your boat to high mountains, you can blow the tube, example a tire inflated to 24 PSI at sea level will have 35 PSI at 3,000 meters high. Have not taken by boat to high elevations to make a comparisson, but the same pressure issues applies.

Have been using pressure manometers for the last 15 years, love traditional inflatables, which I sell. Never had a problem related to seems ruptures nor transom being unglued from the tubes, love the speed these boats can achieve being correctly inflated to their working max pressure which is 3.5 PSI.

In winter the boats are inflated prior to water launching to 3.5 PSI or 0.25 Bar, in summer, shade the boat first and inflate to max 3.0 PSI or 0.20 Bar, the sun will inflate the tubes a little more, or once on water check the pressure after about 15 minutes of sun exposure and deflate if necessary to working max pressure.

If the boat has automatic pressure relief valves forget all about all this pressure issue. Was purchasing Scoprega Bravo Manometers from Defender USA, sorry to say but are being delivered factory faulty, that is, have not precise readings and some will blow literally your boat because of over inflation, read less than what’s shown, so you will end inflating more passing the recommended max pressure; a real danger indeed. Won’t recommend foot pumps having a attached pressure manometers, they will give erroneous readings while pumping, are not exact, stay away from them. Best options can be electrical ones that adjusts air flow from 1.0 to 3.5 PSI. Or buy pressure manometers from Zodiac or Achilles brands and have a good machine shop make a precise valve adapter for the air valve your boat is presently using.

As to get an overall idea I work with Halkey Roberts Air Valves, a friend of mine who owns a machine shop (revolver machine) has made me this nice valve adapter, works marvelous well, would recommend you all to use pressure manometers, your boat tubes will be delighted being correctly inflated, all at the same working pressure.

If anybody would like to have/count/use a reliable pressure manometer, know a nice Korean Factory that produces/sells them, very cheap only US $ 6.50 each + shipping expenses, can ship via Fedex - DHL) worldwide. You will need to make the valve adapter if different, are being delivered to match Korean Halkey Roberts Valves (Gray Pin) , a bit different in diameter and pin height than American Halkey Roberts ( Yellow Pin) Just email me to send the person’s name who to contact and some photos of modified valve adapters using this manometer brand to get the idea.. Happy boating… Only 2 more months to our summer..yeah!!

Locozodiac

[Rogue Wave]

when I have picked up new boats from te toobers to deliver on to Revenger for Fitout I deflate the toobs and tie them up tight so they dount bounce about. Hey presto no prob's

[Poly]

Originally Posted by Locozodiac

Don't you ever inflate to working pressure at sea level and take your boat to high mountains, you can blow the tube, example a tire inflated to 24 PSI at sea level will have 35 PSI at 3,000 meters high. Have not taken by boat to high elevations to make a comparisson, but the same pressure issues applies.

I think you mean 30,000 ft (which is impossible to take your boat, or in practical terms a tyre to!). At 3000m the pressure difference (to sea level) is less than 5psi.

[jyasaki]

Originally Posted by Polwart

I think you mean 30,000 ft (which is impossible to take your boat, or in practical terms a tyre to!). At 3000m the pressure difference (to sea level) is less than 5psi.

Even so, a tube inflated to a max working pressure of, say, 3psi (or an absolute pressure of 17.7 psi) will certainly not like having the ambient pressure reduced from 14.7 to 9 psi. That would be the equivalent of staying at sea level and inflating the tubes to 8 psi (or at least trying to.)

I believe he was talking 3000 meters.

And, to be fair, tires go to 30000 feet pretty often (though, granted, not car tires...)


jky

[Poly]

Originally Posted by jyasaki

Even so, a tube inflated to a max working pressure of, say, 3psi (or an absolute pressure of 17.7 psi) will certainly not like having the ambient pressure reduced from 14.7 to 9 psi. That would be the equivalent of staying at sea level and inflating the tubes to 8 psi (or at least trying to.)

not disputing that

I believe he was talking 3000 meters.

in which case the numbers are somewhat exagerated!

And, to be fair, tires go to 30000 feet pretty often (though, granted, not car tires...)

good point - I had forgotten about them! There are similar debates in the cycling world about flying bikes around the world...

[Locozodiac]

Know inflatable boat makers inflate tubes at the factory to test them at 4.5 PSI for 12 hours for PVC and 6 PSI for Hypalon under shade. The tire example was talking about: 3 thousand meters or about 9 thousand feet on a sunny day. Sun and altitude increses very much the presure of any item containing air.

Imagine a boat inflated to 3.5 PSI at sea level and taken to sunny 5 thousand meters high elevation, will be blown on it's way up. Have seen small inflatable boats blown on high mountains, the owners didn't know about presure issues at high locations when transported from sea level, a real pity

The opposite will be, a boat inflated to 3.5 PSI at a given location altitude, let's say 5 thousnad meters high will have no problem coming down to the coast, tubes will be defleted gradually on it's way down and will look somewhat like big large raisins once at sea level. If the boat is equipped with automatic presure relief valves as in more costly boats, no problem at all.

Anyway in my particular experience the use of a precise presure manometer is a must with normal PVC & Hypalon boats.