Inflatable Dinghy

[tadhana]

Tadhana - which RIB dealer did you work for? I dealt with many of them on the East coast all the way down to Florida where I bought 3 of my RIBS.

I worked for Zodiac of North America. I was in Customer Support and in Engineering for Zodiac and Avon. I taught Zodiac/Avon repair classes for dealers. I was and am still on a first name basis with most of the leading US inflatable boat dealers and repair shops. I sat on the ISO committee developing standards for Inflatable boats. I have worked with factories in UK, France, Wales, British Colombia and Spain. I have engineered ribs and done endurance testing on ribs for hundreds and hundreds of hours.

 

[smitty477]

"I worked for Zodiac of North America. I was in Customer Support and in Engineering for Zodiac and Avon."

That is really great we bought a bunch of Zodiac parts from Zodiac direct in past years some from boater world. We actually liked their manometer the best and have used that unit on many different brand RIBS. Those gages from Zodiac were what turned us on to the large pressure increases during temperature excursions. Had a YL-380 with PVC tubes that we replaced with Zodiac Hypalon tubes at one time. Also had a YL-420 that was a pretty nice RIB. The Avon we had was not a RIB but about 10'6" if memory serves me well.
I have had some similar experiences in engineering and development but not with boats - it was a lot of fun considering it was work.

 

[Peter B]

I read somewhere where wasn't actually the air but the moisture in the air that cause the expansion and contraction. That's why they fill car tires with nitrogen it is dry and does not expand or contract

By volume, air contains 78.09% nitrogen

Yes, sorry, have to agree with Gaston here. The use of pure nitrogen in some tyres is to prolong the life of the rubber by reducing the oxidation of it caused by the oxygen 21%(roughly), in air, not because of moisture, etc.
In other words to exclude oxygen, as nitrogen is more chemically inert.

 

[koliver]

No they don't, actually, but as pointed out by Tad Hana & Capt Bill, above, and stated categorically in the manual that came with my inflatable dink, if you only use the foot operated pump that comes with the dinghy, it is virtually impossible to over-inflate them, even when they then expand/firm up a bit more in the sun. So be happy, pump it up in the am if needed, and don't worry.

When I bought my first inflatable, the foot pump it came with had a surface area of over 40 square inches. I weighed less than 160 lb, so the maximum pressure that I could apply by foot was less than 4 psi. The mfg of the inflatable recommended an inflation pressure of 4 psi. My present pump is a cylindrical pump of 4" diameter, πr² where r=2, is about 12.5 sq inches. To get 4 psi, you need to apply 50 lb pressure on the handle.

Not many of us over inflate.

 

[BruceK]

My 9yo "Island Inflatables" dinghy(Korean,ahem South, made I believe, we don`t make much anything here) has an inflation valve and another valve on each chamber, has to be an overinflation relief valve.More likely to operate due to heat increasing pressure, than me using the miserable pump supplied.
FWIW, I`m fixing a leak at present,but it`s not been a bad dinghy. 2.6M and rated for 10hp motor, planes with my 6hp.

 

[BandB]

This is a subject that Tom Brady and almost everyone in New England is well versed on. Don't forget to pump it up!!! ��

Everyone understands that except Roger Goodell.

 

[Capt.Bill11]

They have been around since 1943 and most if not all inflatables have had them standard for as long as I can remember and thats a long time

Interesting, I don't think I've ever seen an inflatable with one.

 

[Bacchus]

There is more to using nitrogen than marketing.
USN uses nitrogen in our aircraft.

Yes, sorry, have to agree with Gaston here. The use of pure nitrogen in some tyres is to prolong the life of the rubber by reducing the oxidation of it caused by the oxygen 21%(roughly), in air, not because of moisture, etc.
In other words to exclude oxygen, as nitrogen is more chemically inert.

The benefits of N2 in tires are multi faceted...
The physics - smaller molecular size so smaller Press fluctuation due to leaks
Also expands / contracts less w/ Temp change than air

The Chemistry - It does reduce oxidation / degredation

It is "Dry" and reduces bad affects like corrosion of steel rims

The above do not necessarily make it "better" in a lot of applications...Agree it helps in some specialized applications

Planes go through a lot greater temp fluctuations than autos / dingys

Race car tires get HOT and a half PSI makes a difference in handling...and cost is not object to get a minor benefit. They couldn't care less about oxidation - after all the tires don't even last a full race!!!

The same tire shop that tries to sell you N2 will use a water based lubricant to mount the tire putting moisture inside - counter productive

Everyone can choose whether to put N2 in car tires (or dingys) but you should try to understand the realities and just because it is better in some situations doesn't make it better for all

If you choose to use N2 just be clear about the +/- and why you are using it based on science vs anecdotal references or marketing hype.
There are no / little negatives - other than it will cost you more - question then is it worth it?

Is everyone that's using N2 in their cars also using racing oil in their engine??? Another incorrect thought - if it's good for racing it should be great for my Sunday driver - another bad assumption in my book

During a 6 day white water trip I noticed the guides were very anal about letting air out of the inflatable rafts when we stopped for the day / night and re-inflating every morning...after some discussion they said cold / cool water requires one inflation and when they pulled them up on shore in the afternoon they were concerned w/ expansion & over inflation in the sun.

We may need to think similarly when "pulling" a dink out of the water.