Inflatable pressures.

[Rabbie]

I have no experience of inflatables. Having just acquired a very good used one, I want to know how to get the right pressure on inflation. Is there a guage that I can buy (valves look a bit complex)?. Also, on a hot day, is it prudent to let out some air before the inevitable happens?.
Thanks,

 

[charles_reed]

Varies from Inflatable to inflatable.
On mine the keel and floor inflate 2.4 bar and the rest to 1.6 bar.
This is controlled by a double-action pump, with the main pump you can only get up to 1.6 bar, after which a plug is forced out and the internal, much smaller pump carries on to inflate up to the keel/floor pressure.
As the dinghy and pump are in Argeles-s-Mer I can't tell you the name, except that it is distributed bu Plastimo, made in Italy and, guess what, only has instructions in Italian.

 

[ToMo]

I only use the pump that was supplied with it......somewhere in the blurb it tells me that provided I only use this pump I cant over inflate it. I don't think you have to worry about heat expansion if it is kept in the water.

TôMö

 

[vyv_cox]

I recently burst the diaphragm between the forward and one of the side tubes, at what I assume was a lot less than the final, all inflated pressure. Lesson learned: inflate in stages. Don't inflate one section all the way but partially inflate, move on and then come back.

 

[ccscott49]

Funnily enough thats how they tell you to do it in my Zodiac manual!

 

[Rabbie]

Thanks all for the tips. I would never have thought of that one Vyv!.

 

[rob]

Rabbie,

Dont do what i used to do when first getting a second hand one many years ago.
I used to inflate each tube as suggested in turn, then when trying to get the best possibe pressure kept pumping till the tube to the pump blew out.
But in my defence it never over inflated.

Rob

 

[schilde]

Surely if you burst the diaphragm, or a seam in it, then it must be a sign your dinghy's life is nearly over anyway. I can't believe that join is any weaker then the external ones. If it was, it might as well not be there because one failed tube would therefore cause the other to fail and you might as well not have separate ones.

Inflatables are really tough and I read somewhere that you cannot over pressure the tubes with the pump they supply.

I do agree you should pump up gradually and in order, otherwise a crease could put a lot of stress on a seam before it was all straight.

Do buy a dignhy that has valves you can let it down with, not ones where you have to take out the valve. My Plastimo is the latter and it managed to collect rain and spray inside the tubes while it was on the foredeck. And no, you cannot let it down and then put the valve back in, you can't get all the air out if you do.

hth

Steve

 

[Guest]

Pressures ... BAR ..... pipes blowing out ....

I pump mine up with a 12V air pump and then about 5-6 storkes of the foot pump supplied to get final stage.

How hard is it ? I can press my hand onto the tubes and get slight depression without creasing. If I cannot depress the fabric a little then its TOO HARD

As to letting alittle air out .... I pumped up my Narwhal in the garden one year, hard as normal. Sun was beating down and it blew the seams ........ When I took it to the service agents to re-glue the seams, they reckoned that it was on its way anyway and the increased temp / pressure gave it the coup de grace !