inflating and deflating

[squirrelnutz]

Hey guys, I'm new to this forum. I just purchased a 14ft inflatable and I want to get out and use it. The thing is I don't want to buy a trailer for it right now because I don't really have anywhere to park the trailer when I'm done. Is it ok to deflate these things after every use? I'm thinking about just running my 1hp compressor off in inverter to inflate it. Any advice would be appreciated

 

[modernrocketry]

Re: inflating and deflating

I have an Avon that I keep rolled up in the Engine room of my boat. It serves as a backup if my big inflatable has an engine problem.
I keep it in the storage bag that came with the boat and routinely step on it as I am crawling around the engine room.

I fill it with air every year (usually in late August) while on a two week boating trip and my son uses it for fishing. It has served many years living like this. I'm not certain, but I believe it is Hypalon.

I use a stinger shop vacuum to inflate it. Then finish it off with a proper foot pump.

 

[Palssonater]

Re: inflating and deflating

Air Compressor's are high pressure low volume. It would take way too long.

Buy a 12volt inflator that you can use for towables, air matresses, etc. They are low pressure, high volume. Finish up with a footpump for proper pressure.

Much faster! I use a 12volt coleman. I think it was 20 bucks.

 

[bayman]

Re: inflating and deflating

I also like the foot pumps or the high volume double action air pumps similar to this one:

http://www.iboats.com/Airhead_Double_Action_Air_Pump/dm/keywords.air pump--view_id.259662

 

[squirrelnutz]

Re: inflating and deflating

are you able to get the 5psi with those foot pumps when you inflate the keel?

 

[miker-gr]

Re: inflating and deflating

Rib manufacturers on greece suggest to leave the boat always inflate.So this is what i do on my small zodiac and the bigger Planatech i own.
In addition is very boring to inflate deflate every time you want to use

 

[bayman]

Re: inflating and deflating

Most of the low cost foot pumps only get 2 to 3 psi. Some high end models around $65 USD or more can put out up to 10 psi. These are not as common and you may need to do some searching to find them. Some expensive models still only do 2 or 3 psi, but they are built to last longer.

 

[Palssonater]

Re: inflating and deflating

Wow what are you inflating to 5psi?

Not sure about other boats, but reccomended pressure for my Zodiacs is 240mbars. That's 3.4 PSI. My Zodiac foot pumps will easily achieve that.

 

[SnappingTurtle]

Re: inflating and deflating

My boat has each section marked with recommended and max pressure. It ranges (max) from 3-4 psi.

My double action hand pump can easily do double this and cost about 6 Euros, or with the exchange rate being what it is, $9.25.

You can buy electric pumps with automatic shut off functions and they are nice, but pricey. If I had a larger expensive RIB, I think this is the way I would go.

iboats has a lot of mid range pumps, that would be a good choice for those just not wanting to pump.

 

[squirrelnutz]

Re: inflating and deflating

it recommends the keel be inflated to 5 psi

 

[erikgreen]

Re: inflating and deflating

We inflate (top off really) our scuba inflatables with scuba tanks.. the first stage regulators put out about 130PSI, so you have to be careful not to overdo it, but it's nice to be able to fix a low tube on the water.

We store them with some air removed in case they get hot in the sun.

Erik

 

[SnappingTurtle]

Re: inflating and deflating

We inflate (top off really) our scuba inflatables with scuba tanks.. the first stage regulators put out about 130PSI, so you have to be careful not to overdo it, but it's nice to be able to fix a low tube on the water.

We store them with some air removed in case they get hot in the sun.

Erik

Erik, how much pressure increase will an inflatable see on a 85-90 degree day in the sun?

I realize that the color plays a role, but could you generalize a bit, based on yours?

 

[erikgreen]

Re: inflating and deflating

I guess I'd say the tube pressure will double if the tubes are left full in the sun on the black one and probably increase 25 percent on the gray one.

We're not really worried about bursting so much as a long term stretching of the fabric (an upgraded PVC on the black, the gray is hypalon with the hard rubber protectors).

Erik

 

[SnappingTurtle]

Re: inflating and deflating

I guess I'd say the tube pressure will double if the tubes are left full in the sun on the black one and probably increase 25 percent on the gray one.

We're not really worried about bursting so much as a long term stretching of the fabric (an upgraded PVC on the black, the gray is hypalon with the hard rubber protectors).

Erik

Thanks Erik!

Mine is orange, and I was guessing about 15-20% increase, but had really no idea.

I have tried to keep it out of the sun, unless it was in the water in the short time I have owned it. It was purchased used, and what it experienced in it's life before me one can only guess.

 

[deejaycee_2000]

Re: inflating and deflating

just to give you guys an idea, I inflate my main pontoons 0,4 bar (5,8 psi) and my highjackers (bottom "keel" pontoons) 1 bar (14,5 psi) .....

 

[Dry Diver]

Re: inflating and deflating

Erik, how much pressure increase will an inflatable see on a 85-90 degree day in the sun?

I am not sure if it is the same in an inflatable or not but in a scuba cyl for every 1deg in temp difference you go up or down you will get a 5lb difference in total air pressure inside your tank. i.e. If you fill your tank at an ambient air temp/tank temp of 80deg to a pressure of 3000psi then let the tank sit in the sun and the tank hits 90deg then your pressure will now be 3050psi.

Not sure if this helps or not.

 

[nobrainsd]

Re: inflating and deflating

The manual for my '98 futura mk2 indicates that the tube, speed tubes and keel should be inflated to 240mb/ 3,4 psi. The manual also states that a 1 degree C/ 1,8 degree F increase in ambient temp will raise the tubes internal pressure +4mb/ 0,06 psi. They also list an interesting example where a boat inflated to 3,4 psi at an ambient temp of 10 deg C/50deg F is left in direct sunlight on a yacht deck (50deg c/ 122 deg F). Internal temperature can then increase and reach up to 70 deg C/ 158 deg F doubling the internal pressure to 480mb/ 6,8 psi.

Temp increase really impacts pressure big time. Considering all of the conditions my boat experiences during use over a day I think having a pressure gauge is a real necessity. I always bleed off some air when pulling my zodiac out of cool water and placing on my trailer for sure!

 

[SnappingTurtle]

Re: inflating and deflating

I think just to be on the safe side, I will just continue to release 40-50% when I pull it out of the water. It doesn't take that long to pump it back up.

I checked again, and mine is marked for 0,30 bar or 4,2 psi, for the main tubes and floor.

 

[Dry Diver]

Re: inflating and deflating

So would the best practice then be to inflate fight before use then deflate immediately once it is out of the water on the trailer? Or can I wait till I get home that way it will be a little more rigid for the 1 1/2 hour ride down the highway?

 

[nobrainsd]

Re: inflating and deflating

Well, Obviously you dont want to fully deflate the boat on the trailer before towing, might not properly support an outboard The boat doesn't have to be fully inflated to ride nicely. My zodiac is sort of bouncy when fully inflated, dirt roads and trails really go better with a little air bled off. Short paved roads I don't worry about it. For me it is totally situational. If you've been out on cold water and you put your fully inflated boat on a trailer in the hot sun you should bleed off a little air. You don't have to let out a lot, the boat will still ride fine. You know the tubes are going to be heating up so you want to accommodate that right off. The flip side example would be towing my boat at night in Mex. What was inflated, but not overpressured, will often become too low as the fog and cold take effect after sundown. The boat doesn't ride well as the tubes lose too much pressure. You just have to check on the tubes occasionally and particularly when the exposure shifts a lot. Temp has a huge effect on pressure in your tubes. On my first daytime/nighttime run to Mex I was astonished to look back and see my boat cover flopping around on a much diminished zodiac about 1 hour after sundown. It's second nature now to manage my pressure and everyone should have some small pump onboard that can do this.