New Zodiac Fastroller deflation - issue?

[IanH]

On Saturday I inflated my new Zodiac 3.6m Fastroller for the first time. It was not fully inflated, but just enough to get tubes into shape.

This morning I near fully inflated with a new Bravo BST 12 HP pump to just below the recommended pressures. Approx 11psi floor and 3psi tubes I think. Pressures were checked with the manometer supplied with the Zodiac and showed that pressures remained as expected ie approx 11/3psi.

I then left the boat for a couple of hours and on my return, I deflated it. To my surprise all the buoyancy tubes lost pressure even though all 3 main tube valves had not been fully opened. I cannot remember the exact order I deflated, but port rear tube was very deflated even though only bow and starboard rear valves had been opened.

I had not expected this as I had assumed that all compartments were independent and thus would remain fully inflated until its valve had been opened.

Is this to be expected?

Thanks

-Ian

[beamishken]

Hi That happens because although the chambers are independant if the tubes are deflated in a different order to the way they were inflated the bulkhead between each chamber can relax into the adjoining tube as there is nothing for it to push against you will probably find if you inflated the adjoining chamber it would go hard once the bulkhead was fully deflected into the fully deflated chamber

however if the first chamber re inflated as you inflated the 2nd then there is a leak in the adjoining bulkhead

hope this helps

[IanH]

Thanks.

It's all deflated now but I will test by inflating all to 50% (as per manual) then fully inflating the bow tube. Both stern tubes should then remain inflated at approx 50%?

[beamishken]

best filling tubes till they are firm not hard & see if they hold pressure then do the same with the adjoining tube untill you have done all chambers individually then you have proved each chamber

[Flyguy]

I normally put 3.4 psi in tubes and 11 in floor. I inflate the floor first then the front then the sides. When I deflate I do the front first then the side tubes then the floor. The front tube is cone shaped so influences the pressure on the side tubes.

[IanH]

I think I did it in the order you said. I only partially inflated at first as I was using the foot pump - soon realised that I needed an electric pump.

Do you do a partial inflate first - manual says 50%? I assume the floor is fully inflated first - manual implies this. Not sure what psi partial inflation is on my bravo bst pump. Probably a bit of trial and error.

Not sure if you have one but do you know if the bucket (int-l box) in the front tube is inserted before the floor is inflated or after. I put it in after I had partially inflated the floor and it was a right pita. The only thing I can see in the manual about this is that it must be inflated before the tubes are inflated.

[falcon0310]

i had the smaller 285 and juile at chas newham said valves need adjusting sure the boat ok hope this helps

[IanH]

Sorry to sound dumb but i'm new to inflatables. What does adjust the valves mean and what will it cure ? I did have another issue where after removing the inflation tube, 2 of the 3 valves opened. Not sure if I'm using the wrong end piece adaptor - one had a plastic bar within the tube which differed from the one on the foot pump. I wonder if that had anything to do with it, like pressing in the green valve button.

Zodiac manual is erm, not very enlightening shall we say.

[Locozodiac]

Inflate, deflate each tube separately to at least 3.0 psi, that way will know that all bulkheads are intact and every chamber inflates and holds air properly. Best is to inflate side tubes first then bow, last is air floor. You could start inflating all 3 tubes to 1.0 psi and then add 0.5 or 1.0 more psi untill working pressure is reached. That way all tubes will be equally inflated when done.

For deflation try to open all air valves at same time, if your valves are flap diaphragm type (not spring type) unscrew them farthest away from valve without removing so to lose some pressure, once done you can remove them from main valves.

Happy Boating

[IanH]

Hi

Thanks for the advice but thats all the opposite of what flygy suggested which is probably what i did first time out when I started to inflate by foot pump. The manual says inflate floor first. Why do you say last?

Zodiac manual is poor. Not sure if when it says inflate tubes to 50% then 100% it means by volume or by pressure.

[RIBFIXER]

The reason you only partially inflate the tubes before the floor is , if you do not then when you inflate the floor to 800 mb if the floor is not located correctly you can stretch and warp the boat out of shape. This will nullify your warranty and effect the performance of the boat.The reason yo have experienced partial deflation to your tubes is that the baffles on all Zodiac boats are very large and the baffle will move back a long distance giving the impression of a large leak, just re inflate the deflated chamber and all the remaining chambers should come back up to normal working pressures.
Hope this helps.

[IanH]

Thanks for the info RibFixer. Now that you have explained about the large baffles, I can see from the diagrams in the instruction manual why, as you say, it could look like a large deflation when an adjacent tank is emptied.

However, i'm getting mixed instructions regarding the order of inflation and from your post RibFixer, note now that even the Zodiac manual could be interpreted in more than one way.

Im just trying to get the correct procedure. I thought I had it but I am now not so sure as people have posted different versions.

In the Zodiac manual, it gives a small table of assembly procedure. I had previously looked at the more detailed inflation instructions as the definitive version. Taking the relevant bits out of the assembly procedure table, it reads as follows:
2. Install bow stowage box
3. Activate values into inflation position
5. Begin inflation of the boat (not completely) - this is the extra step from the detailed instructions below.
6. Inflate the H2P floor to correct pressure
8. Finish installation of boat to correct pressure.

Now, looking at the detailed instructions, it reads as follows (3 sections):
Cadet fastroller Active-V - Air floor inflating procedure

• Before inflating, open out the boad and position the keel in the central band of the bottom and on the floorboard axis (centred between the positioning pins).
• First, inflate the keep-floorboard assembly to its rated pressure
• Check that the keel inflated perpendicular to the floorboard and that it is still positioned on the central band of the bottom (otherwise reposition)
• Inflate the main bouyancy tube
• Press the floorboard down around the edges to fit it into the follow of the angle

A: Inflate the active-v floorboard/keel assembly
1. Activate the valve into inflating position
2. (with foot pump) Inflate in position A (low pressure) until it becomes difficult to operate
3. (with foot pump) Finish inflation in position B (high pressure) until you reach the correct pressure (800mb/11.3psi)

B. Inflate the main buoyancy tube
2. Inflate the main buoyancy tube and the keel (assume this is for aero model not active-v) until it (the foot pump) becomes difficult to operate. Correct pressure = 240mb - 3.48 psi

It then has a series of diagrams explaining not to inflate a compartment to full pressure if other compartments are totally inflated. Suggests 50% then 100% inflation but im not sure if this applies to pressure or volume.

As you can see, the detailed instructions make no mention of inflating main tubes partially before floor/keel where as the procedure table says 'begin inflation (not completely)' and fails to mention what 'not completely' means, ie is it until they start to raise into shape, 50%, or something else.

To add to the mix, I have just bought a Bravo BST 12 HP pump with auto cutoff between 100mb and 800mb. Im too old to pump with my foot and want to enjoy being out on the water rather entertaining onlookers. So I'm not sure if I initially partially inflate main tubes by eye to 50% by volume, or to 100mb (approx 50% by pressure) then fully inflate.

I think inflating the bow tube first looks most logical. Presumably I deflate last, albeit in quick succession.

[RIBFIXER]

Hi.inflation procedures are a bit open to interpritation, but as a rule of thumb
1 check to see where the baffle seam lies in relation to the nearest valve,the baffle should inflate away from that valve.
2 From memory you start with the port rear chamber and then the bow and finally the starboard rear . But re check your instruction manual.
3 For initial inflation only inflate the chambers enough to give the boat shape to ensure the floor is correctly positioned as I said before ,the exact pressure at this stage is not really important.
Hope this helps.

[beamishken]

I wouldnt inflate each chamber to full working pressure if the adjoining chamber isnt inflated'
the bulkheads are not designed to have full working pressue on them with nothing on the other side the manual means 50% by pressure so you bring the pressures up equally so as not to overstress the adjoining bulkheads
the valves usually have a position which holds them open usually by turning the inner pin 1/4 turn to lock it in the open position for deflation I think this is what the "adjust valves" is refering to

[Locozodiac]

Originally Posted by IanH

The manual says inflate floor first. Why do you say last?

Inflatable manufacturers have different order inflation recommendations, if having a removable air mat the order is of no importance, the order of factors, don't alter the product. That is tubes must accomodate against air mat, or air mat must accomodate against tubes. If having an issue with inflation order, inflate gradually on a mery go round basis untill top recommended pressure is reached, keel inflates last. Will probably need to top once sib is resting on water for best performance and least hull drag.

If you want to buy used sibs and avoid hidden surprises you must inflate all tubes separately one at a time, (inflate/deflate) to at least 3.0 psi to know that individual baffles holds air properly. If buying blind and with issues will need to live with it.. Not an issue testing to 3.0 psi individually as manufacturer's test them to 5.0 psi when passing quality controls.

Happy Boating

[lightning]

I have a Zodiac 285s and if l inflate both tubes about 70% then inflate one fully, the other becomes hard too, and only requires a short period of inflation to reach full pressure. I assume this is due to the internal part of one tube expanding into the other, as suggested above.

[IanH]

I did some tests today and thanks to replies, especially ribfixer, all looks good.

I inflated to 50% bow then two stern tubes. Then finished inflating the two stern tubes then bow. After leaving it for a few hours, I then deflated bow until it became less firm. One of the stern tubes remained fully inflated (the one that I was originally concerned with) whilst the other dropped in pressure.

Now that I understand how the baffles worked, I realised that one of the baffles probably moved, causing pressure to be lost in the other tube. I then re inflated this tube and the bow partially inflated and took hardly any air to go hard.

I then reran the deflation test, knowing exactly where the baffles should be and this time, partially deflating the bow, the two stern tubes remained solid as I expected.

So there is no transfer of air between the tubes except as allowed by any change in position of the baffle which can make it look like an adjacent tube has deflated.

-Ian