Outer Limits 4x4 Board

what are the rules and regs of welding and modifing air tanks (e.g. i know of many air tanks that have been made an intergrated as part of the roll cage in utes?) ive heard that if you weld an air tank of any kind you run the risk of weakening it? is this 100% true? cos i have mates that a wanting to weld mounts to the air tank/roll cage for lights and have been told that if they do that they run the risk of causing major safety problems

so if its a safety prob then why have a sh1t load of blokes modified ther utes roll bar to hold air? what happens when you roll it onto the roll bar and damage it...wont it explode?awwe bugger this is head ache material if i have ever seen it

the sort of air tank you're talking about, to hold about 120 PSI, doesn't really have to be very strong. a beer can or PET bottle easily holds that sort of pressure (from memory the vapor pressure of carbon dioxide is around 600 psi at room temp) - so whether or not laws apply, the danger is fairly limited - it you whack an air tank with 120 psi hard enough to rupture it, chances are the air will go "hisssssssssssss" out the crack/hole and nothing much exciting would happen.

it's possible* to calculate the energy stored in a compressed gas given the temp, pressure, volume etc, then compare with say the energy required to lift something heavy or acclerate it to a given velocity, and for 120psi you need significant volumes to do any real work. it's a borderline pressure between tow low to be useful and too high to be safe.

if you're talking about very high pressures like SCUBA, it all changes; those sorts of pressures are dangerous for even small volumes.

anyway my OPINION is if you want to carry 120psi in the barowrk, go for it. it's not dangerous. if you get pulled up for it, say it's a water tank.


* but too difficult for me to do off the top of my head. I'd have to go and get a textbook or something. and screw that for a game of skittles.

we're talkin about my tank that i use as a roll bar ... its paul staibes old
tray and roll bar combo ... i want to weld some extra tags for lights on the
bar ..... the air tank will only be used for inflating tyres .... so 150psi is
bucketloads of pressure

as long as you're handy with the welder and not likely to blow through the walls of your bar pipe, go for it. I'd make sure the tabs I was welding on were thinner material than the wall thickness of the pipe, and keep the amps low, so the penetration on the pipe is acceptable but minimal; so it if breaks, the tab snaps off rather than tearing a chunk out of the pipe.

Hey Rosco, you just need to find the right welder to do the job with no damage to bar work or piping. Hint, hint.

DAZZA-LUX wrote:Hey Rosco, you just need to find the right welder to do the job with no damage to bar work or piping. Hint, hint.

the only problem is that you are in farken MELBOURNE and not in townsville...still i know the beter place outer the 2

So Dazza (newbie are you volunteering to weld my sliders/sidebars?

toonfish wrote:So Dazza (newbie are you volunteering to weld my sliders/sidebars?

Dazza, you could come up to sydney and do mine too

Nev62 wrote:

toonfish wrote:So Dazza (newbie are you volunteering to weld my sliders/sidebars?

Dazza, you could come up to sydney and do mine too

The Hell-Raider has an air tank/roll bar??? fulsik!

Terrafirma wrote:we're talkin about my tank that i use as a roll bar ... its paul staibes old
tray and roll bar combo ... i want to weld some extra tags for lights on the
bar ..... the air tank will only be used for inflating tyres .... so 150psi is
bucketloads of pressure

"150PSI is bucketloads of pressure"....hmmm maybe for inflating tyres or being able to run ari tools - but if the maximum pressure contained is only 150PSI it's NOT that much pressure....a as said above scuba etc where we're talking '000s of PSI is bucket loads.....1-200PSI will just sound like a bloody big whooping cushion if holed under pressure

Besides wouldn't common sense dictate that the pressure be removed prior to welding, valves left open and then when completed the pressure reapplied.....hence you have 0PSI and as you inflate if it's holed it will simply leak out......

Staibey's old tray is pretty thick material, isn't it? I couldn't imagine a Woomba boy going too thin on the build quality. Just weld 'em on.

So why would the spotlight tag welds be any less safe than those welds holding the roll bar together, unless of course anybody is dumb enough to weld while the tanks at 120psi.

dumbdunce wrote:

Nev62 wrote:

toonfish wrote:So Dazza (newbie are you volunteering to weld my sliders/sidebars?

Dazza, you could come up to sydney and do mine too

The Hell-Raider has an air tank/roll bar??? fulsik!

Nah, it is the sliders I need, tired of "re-adjusting" the side steps after going for a drive.