OBA: Steel or Aluminum Tank?

So I am putting together a Power Tank-esque CO2 system. I have found sources for both steel and aluminum tanks, but don't know which is safer. So which tank material is safer/better(safer being the priority)? And why? Thanks in advance for the help.

Fergie

IMHO, aluminum is probably a better choice because:

- aluminum can hold higher pressure (more volume) in the same size tank.
- aluminum is lighter than steel

Safety isn't an issue as long as the tanks have been fabbed by a reputable shop. Aluminum will develop fatigue as much as steel when repeatedly flexed (this is important because the tanks are constantly flexed as they are filled and drained), but a hydrostatic test will help you sleep better. For any pressure greater than 100 lbs, I recommend a semi-annual hydrostatic test to 150% of the max rated pressure. Failure rates are marginally higher for steel tanks vs. aluminum when used in similar applications (scuba, f'rinstance, but the pressures there are much greater (1500-3000 psi) than you can expect from a home compressor).

Other considerations: a drain petcock is a very nice feature to have. Moisture condenses out of expanding gases very quickly and collects in the tank. This will rust out a steel tank pretty quickly and corrodes an aluminum tank almost as badly. This can be potentially deadly if ignored. All compressor tanks have them, DIY tanks (OBA or otherwise) should, too.

It's nice to have a take with a painted interior. Helps keep moisture from eating away at the tank from the inside out.

Anyone else care to weigh in on this? Thanks

Fergie

i dont know about comparison, but i use an AL tank for the same style setup. it works great, the price was right, and the weight difference sells me on the AL tanks.

www.beveragefactory.com has decent deals on AL tanks, i bought my regulator from williams balloon supply- http://www.williamsballoons.com/co2_regulators.htm youll need the 150 male, whatever PSI rate you want. if you dont want a fixed reg, then try Holox or another commercial gas vendor. sometimes you can pick up a good dual gauge reg from them for 30-40 bucks used.

well i use the 150male regulator at 100psi from williams. it works fine for air tools, and it fills the tires nice and fast. i have about 92psi at the hose outlet (you get some pressure drop in the hose)

i do want an adjustable regulator though, and i have a line on one here soon from holox (once im done using it at work). ill let you know how it fares.

I don't see how either water or CO2 could corrode an aluminum tank. I thought one of the biggest advantages next to the weight was the resistance to corrosion as it forms a protective oxide around the bare aluminum.