DIY: On Board Co2

Cross posted to 2nd Gens.

Alrite folks, this may or may not exist here already (I'm sure there are hundreds of these posts online), but maybe someone will find it helpful.

PowerTank sells a basic, 10lb (fill weight) Co2 cylinder for $380 +/-, it includes a gas cylinder with carry handle and an air hose/tire filler. For roughly half that cost, you can make your own on-board cylinder air and have double the capacity.

http://www.alphaexpedition.com/10-lb-basic-system/


For purposes of this post, I'm not looking for the cheapest internet retailers to link to, just showing what parts you can buy, what their ballpark cost is, and what you really need to get this on your own rig for far less money.

Co2 cylinders come in many sizes, PowerTank uses a 10 lb cylinder, which is fine, but 10 lbs goes quickly and the cost difference for the cylinder itself and also the Co2 gas fill isn't really much at all, so I'm suggesting a 20 lb cylinder for the context of this thread. An aluminum cylinder doesn't rust, it looks nice, and it weighs a good bit less than a similar steel cylinder and that's what I recommend.

Here's what you need to build your own transportable air system.

20 lb aluminum Co2 cylinder. 20 lbs FILL WEIGHT of Co2. This holds your Co2.
http://www.beveragefactory.com/draftbeer/tanks/co2/C20.shtml

Nut and barbed stem fitting - this can be sized up to 3/8" which I personally prefer, and you can find a 3/8" fitting identical to this 1/4" pictured for $1.50 or less. This allows you to connect your high pressure tubing directly to your Co2 valve.
http://www.chicompany.net/index.php?main_page=product_info&cPath=375_20_312&products_id=1563

3/8" nylon braided reinforced high pressure PVC gas line. This is how you connect your tire filler.
http://www.chicompany.net/index.php?main_page=product_info&cPath=375_86_87&products_id=713

To attach the 3/8" tubing to the barbed stem at the cylinder valve, and also to attach your 3/8" barbed stem which you'll attach to your tire filler you'll need clamps. You can use hose clamps, though their design isn't ideal for this type of tubing and high pressures, which may cause leaks both at the cylinder valve and also your tire filler. Oetiker clamps are superior and cause no damage while providing a tighter, more secure fit, so I'm recommending them here.

Oetiker clamps. This will securely attach your high pressure line to your barbed stem fittings.
http://www.chicompany.net/index.php?main_page=product_info&cPath=375_86_88&products_id=179

Oetiker makes their own tool to use their clamp, but as you see the tool you can probably figure out a substitute, though they're not expensive and work great.
http://www.kegoutlet.com/oetiker-clamp-tool.html?gclid=CM_purLhucECFcyyMgodKDAA4Q

Tire inflator with regulator, ARB brand.

$48 ARB ARB605A Tire Pressure Monitor Inflator and Deflator with Analog Gauge and Flexible Hose in Blue

http://www.amazon.com/gp/product/B0036ULEV0/ref=pd_lpo_sbs_dp_ss_2?pf_rd_p=1944687682&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B003N2UWX2&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=04RPPWWBXZ7ZNFE8PVF2

You'll need to thread a 3/8" barbed stem into the tire filler so it can meet up to your 3/8" high pressure gas line. Again, this piece is $1.50 or less, and can be found at most hardware stores.

The brass nut and stem you attach to the Co2 cylinder will seal very well, as brass is soft. If/when it starts to fail or you want to prevent any leaks from happening there in the first place, I highly recommend picking some of these crushable composite washers between the face of the tank valve and your stem. Ideally you'll use a brand new washer each time you re-fill your Co2 tank and re-attach your nut/stem/tubing to use the system.
http://www.chicompany.net/index.php?main_page=product_info&products_id=604

That's all you need. The PVC line isn't too friendly with UV damage, so if you keep it out in the sun all day long you'll want to replace it every other year (or more, it will develop cracks easily visible if it starts to fail), but if taken care of you can use the same tubing for 10 years.



All of this stuff can be found locally and any welder's supply company will sell you aluminum Co2 cylinders, regulators, and most hardware stores will have the brass fittings, if not, a beverage/beer supply house will have them. If those aren't local to you, the internet is your friend.

Building a similar setup is a lot less expensive if you don't need the name brand sticker on it, and of course there are other ways of doing this and different parts you can use and accomplish the same thing, but I've personally used a cylinder setup as I've outlined here many times and have no issues.

Lastly, the difference is cost between filling a 10 lb (fill weight) cylinder and a 20 lb (fill weight) cylinder is minimal, if different at all. Locally they charge $16 for a 5 lb (fill weight) cylinder fill, and it's $18 for a 20 lb cylinder fill.

Hope this helps someone, or gets their creative juices flowing to create a low cost PT alternative.
__________________

 

Fixed broken links, sorry for anybody who had issues.

 

Eventually that line is going to get brittle and blow out on you without a regulator to knock the pressure down some. I have read in some firefighting equipment paperwork that CO2 stays in liquid form at just over 800psi at room temp. What pressure and temperature is that semi-rigid hose that you are using rated for?

You should add a regulator,

 

And probably read this before you start offering a low cost, unsafe OBA setup.

 

X2 I run the adjustable one with this hose On a #20 beverage tank the set up work awesome and the hose coils up nice after use.

 

I've been looking to do a DIY build on air and this is exactly what I'm looking for. This post was from many years ago and I'm curious if you're still running this setup? If not, what issues did you have? Thanks!

 

I dont think James mini van has OBA. Amirite?

@T4RFTMFW

 

how many air ups can you expect to get on say 4 x 35" or 37" airing up from say 15-20PSI to 30PSI all the way around...I have an empty 20# tank I need to get filled, just wasn't sure if there was a WAG for how many trips i can use that tank prior to a re-fill...would suck to air down to 10 and find out the tank is empty when i hit the pavement.

 

https://powertank.com/pages/tire-air-up-chart

 

Thanks...just so I'm reading that right. 20# tank, adding 15psi to 37/12.5r17 gets me just over 10 air ups all the way around? 42 tires filled total?

Awesome info if I'm reading that correctly. Easy to log.

 

That is how I interpret the chart as well

 

Ideally, you'd want to weigh the tank while empty.

Once you get it topped off, you'd want to weigh it again.

This way you can accurately figure out how much co2 you have left before "chancing" it.

I still have co2 left over in my 5lb tank but I get 20-24 tires going from 15psi to 32-33psi on smaller 32" tires