Scuba Tank for On Board air... stupid qestion?

[Guinness44]

May be the portable ARB compressor is the way to go, at least it wont run out of air, if it does, we all are in trouble. We have had ours for 10 years now, it works well, no fancy stashing. We use it in the box, so we can use it in whatever vehicle we drive (not wired/installed for good).

 

[xcmountain80]

Yeah having a air pump is nice but gaaaaad it takes forever. I was thinking a tank for day to day or run to run and the OBAC for backups. I run a viair 450c and it does live under the hood and is exposed to everything the engine is decreasing it life w/o a doubt. It takes roughly forever to fill 4 33's from 18-45psi. It is still within the operating range compared to the OJ test, so 3-4 min ea. a tank would knock em out 30-40 sec. ea. . Power tank has some or had some blem tanks on sale for $330 with all the goodies.

Aaron

 

[mog]

A 'trick' I use is to avoid the large regulators with breakable gauges is to use a fixed pressure regulator. These are most commonly use as regulators for helium balloons. No, I'm not saying to put helium in your tires to float down the trail .
I adapted mine (set to 30 psi) to a portable nitrogen bottle. I use nitrogen only because I'm an aviation mechanic and can refill it for free from the bottles we have at the hangar for the aircraft. I hydro it every 5 years, and I'm good to go with free 'pressure'.

 

[mog]

I have an aviation oxygen tank that I intend to convert to on-board air use.

A work of caution . You got the bottle cheap, because it is past it's 'life limit'. Aviation oxygen bottles are constructed much lighter (for obvious reasons) then standard high pressure bottles. They need to be hydro checked like normal bottles (a DOT requirement not FAA), but have a limited life due to their construction. Also they are much more susceptible to damage then a normal bottle (on aircraft they are under floors, behind bulkheads, in areas not normally associated with damage (other then mechanics accessing them), so any scratch, dent, ding would be a bigger issue with them, then with a normal HP bottle. And do not even think about using a composite aviation oxygen bottle past it's life limit, or outside of aviation. Those are extremely susceptible to the above listed damage. Normal high pressure bottles, Scuba tanks, CO2 tanks, are construction with normal wear and tear envisioned, not aviation bottles.
Also that bottle is probably rated to 1800 psi. If it is repainted and re-regulated (I'm guessing your's did not include the original regulator, those are pricey), now if you take it in to fill with say nitrogen or compress air, it will probably be filled to 2500 +/- psi ..... 40% higher then it's rating when it was in it's 'life limit'. Lost in Space Robot voice -- "Danger Danger Will Robinson"

 

[jnaut]

Yeah having a air pump is nice but gaaaaad it takes forever. I was thinking a tank for day to day or run to run and the OBAC for backups. I run a viair 450c and it does live under the hood and is exposed to everything the engine is decreasing it life w/o a doubt. It takes roughly forever to fill 4 33's from 18-45psi. It is still within the operating range compared to the OJ test, so 3-4 min ea. a tank would knock em out 30-40 sec. ea. . Power tank has some or had some blem tanks on sale for $330 with all the goodies.

I'm old fashioned so I'd rather have something that... generates its own air, even if it takes longer. I've considered splitting the difference and just bringing my own 100lb tank compressor along. It runs on 110 volt so I'll need to upgrade my inverter to a higher rated one, but you can prefill the compressor tank and top off a tire pretty quick. But you have an infinite supply of air. No high pressure tanks or co2 re-filling required.

 

[Colorado David]

Mog, I bought the bottle from the estate sale of an engineering test pilot. It was a portable oxygen apparatus, not the permanent (and lighter weight) bottles that are used on general aviation aircraft. Although it is about a third the length of a welding oxygen cylinder, it is the same diameter and is every bit as heavy construction. I talked my plan over with a technician at Air Gas. The cylinder will be tested and repainted.

 

[CharlieV]

I just made up an 80 cubic ft. aluminum scuba tank to use as a portable air source. I purchased a used regulator (old U.S. Divers) off ebay and then took it to my local dive shop, where I have a longstanding relationship, to get it looked over. The owner, a generally taciturn man, frowned at its age and gave me the old "just don't dive with it," speech. He installed an emergency pressure relief valve (about the size of a dime) so in the event the regulator failed the hose would not burst. I used a low pressure inflater hose from a BC and mated that with bushings from a plumbing supplier to a standard 3/8" shop air hose. It produces enough pressure to fill a tractor/trailer steer tire (from 80-105 psi), but that is all the testing I have done with it. Maybe not the best or the safest, but I already owned the tank when I decided to go this route. My cost for the other parts totaled $50 for reg, hose, bushings, etc. DIN tanks will hold more air per overall tank size as they are higher pressure, but I just used a regular 3000 psi tank. Oh, might I add that the dive shop sells a one piece reg and hose for $95, but the hose is only 3' long (the hose acts as the regulator in this case).Hope this helps.

 

[IH8RDS]

A 'trick' I use is to avoid the large regulators with breakable gauges is to use a fixed pressure regulator. These are most commonly use as regulators for helium balloons.

I use a fixed regulator set to 90psi. Works great except I really never know before it is empty. I can only gestimate by weight.

 

[StumpXJ]

Thanks to everyone for the info, I think I may pass on this for now. One, I dont know enough about it, and two, it sounds like it will end up costing as much as a co2 set-up for air.

The tank would cost me about 40 bucks, plus a little gas money.

~James

 

[Casper]

You can get a CO2 tank at any welding supply shop for around $60, then get a regulator from one of the CO2 companies for around $80 (I think that was the cheapest I found). Now you have a complete det up. When you need it refilled, just take it back to the welding supply shop and exchange it for a full one, $13 and you don't have to wait for them to fill, or come back when they have it filled. Thats the set up I have and love it.

Casper
:smiley_drive:

 

[SWbySWesty]

I'd like to bring up this thread and ask that anybody who IS runnign a scuba tank setup if you could please post a picture of how your secured the tank in the bed/cargo area. I have all the gear and filling attachment and am now considering how to secure it in my cargo area (I don't just want to lay it down like I usually do when I go diving).

With more cargo, I have to pack carefully, and obviously it's only used once on the trip doesn't need to be accessible all the time.

 

[xcmountain80]

I'd like to bring up this thread and ask that anybody who IS runnign a scuba tank setup if you could please post a picture of how your secured the tank in the bed/cargo area. I have all the gear and filling attachment and am now considering how to secure it in my cargo area (I don't just want to lay it down like I usually do when I go diving).

With more cargo, I have to pack carefully, and obviously it's only used once on the trip doesn't need to be accessible all the time.

Well unlike a CO2 tank you can run a dive tank laying flat. I would wither get a set of bracket or make them and mount them to the floor. Make sure you have access to the 1st stage. I know nay sayers will tell you a dive tank is dangerous and yes @ 3500 psi in a 80 tank has enough power to lift a locomotive 3' into the air if properly detonated, but I have seen these tank flip end over end down the interstate with no consequence (obviously you could not use them and if you did perhaps crazy), tanks are safe vip em annually and hydro every 5 years.

Aaron

A

 

[SWbySWesty]

I'm all set on tank safety. I am a certified scuba instructor and ex shop manager where I filled more tanks than I'd like to mention LOL

 

[Honu]

scuba tanks work BEAUTIFULLY!!! i used one for quite awhile. holds about 3000lbs of air. just remember that youll only get about 6 to 10 fills on it, depending. i have 265/75's and i could go from 18 to 40 in about 35 seconds or so.

also remember to pad it REALLY well. i didnt and my tank got the anodizing worn off and they wouldnt recertify the tank. it doesnt take much to get a tank rejected. mine had a very slight gouge in it where it rubbed on the side of the bed. in retrospect i should have padded it so that it cant rub on ANYTHING that is even remotely hard enough to scratch it.

otherwise, theyre a great source of air if you already have the tank.

im also assuming that youre a certified diver. if youre not, then youre going to have a hard time getting it filled. MOST places require a SCUBA certification card to fill a high pressure tank.

way old thread
BUT in the above I would have brought my tanks some where else then to get a VIP unless they did not pass hydro for some other reason ? but the outside has nothing to do with the inside ?
unless the scratches were so deep they did something structural to a tank ? you should see the abuse boat tanks get !!!!!
when I lived on Lanai they bounced around the back of a van stacked 6 high every day for years to and from the compressor and we drove those vans into the ground over the rough roads even got airborne in them every day on this big bump hehehehe

I am a X instructor for over 15 years and did a TON of VIPs at shops and when I worked on boats etc.. all the tanks in the islands look like crap on the outside as they get beat up

sadly I think the shop just wanted to sell you new tanks or take your used ones off you for cheap find a new shop !!!!

 

[OverlandZJ]

How about the old Yellow Fireman tanks? I was given one years ago and it's just decorating the garage currently.