I was poking around the net and found this.



http://www.lunghd.com/Tech_Articles/...ear_Bumper.htm

I thought it was a good idea, it would take care of a few problems i was having. I would have a rock bumper and on board air, without taking up space in the cargo area for a tank. Your thoughts? Possible pros and cons?

If you hit a tree or rock on the trail or get rearended, you no longer have an air tank. Probably wouldn't be the best protection if it is hollow. Just my $0.02

issues with an air tank like that

1, I dont see a water tap so the bumper/tank will rust from the inside out with pooled water

2. squares are not conducive to high pressure and the welds will fail or the bumper/tank will bulge. (look at every air tank they are all round to combat the pressure)

3. the fitting are kind of in a odd space to get lines from to fill tires or run an air tool


If I were building a bumper air tank I'd spend a lot of time with copper pipe and make up a tank my self with a water tap at the bottom and some sort of manifold and valve set up. You would build it like a large U shape with soldered joints ext to take the pressures and such.

From reading the post, there is a water valve on the back side. Also the tubing is 4" x 6" 1/4" thick box tubing. That is pretty thick. I am not exactly sure of the strength but I think that would hold.

I've been involved with air systems both at work and in the mini truck world and its been my experience that square or rectangle tanks dont last with internal pressure. I cant name a single system that I've run into that has a square tank. they are all round to take the pressure. 200 psi is a lot on metal and flat surfaces by nature are not as strong as round ones.

It's ability will be 'limited'.

1/4" isnt really all that thick and when it comes to tubing like that the only thing with even alittle roll to it is in the corners
tube is rolled into shape from basic flat steel and it has a seam weld on one of the 6" flats
tube is in no way made to have internal pressure youll be lucky if it just splits the seam
as a structural welder code requires we add a vent hole in box tube when caping the ends to prevent pressure build up from the welding process because the pressure if left in there will cause the peice to fail as it expands and contracts do to temp changes

My concern would be if it were charged and you got hit from behind. It would seem as if you had a bomb if that thing ruptured. Just my .02$

I have seen roll cages used as an air tank.

Yeah f that, I wouldnt want a tank for my bumper.

more then likey being hit with it full of air will more times then not just bust the seam weld and there will be a loud rush of air if it comes down to the tube exploding it would more likey be from an over load while you were filling in in which case you'd be ****ed

Id rather not find out. But I have popped bags in my hand and the seam didnt just give out.

All very good and informative points. Thanks guys!!! I was just thinkin this would be better than having a tank in the cargo area or under the xj.

I can't remember what forum it was, but I read a build thread where someone fabbed new rockers/boatsides out of 4x6 box with 1/4 wall and said it worked great

Just cause it works great doesnt mean it is a structually sound Idea. I have seen a lot of ppl build things out of material that was not intended for that purpose. By not failing immediately and working adequately.. other ppl perform same mod.. well then eventually it fails, and a bunch of ppl have time bombs


So to OP I say do it.. and telll us how it works for you in 5 yrs...