Considering a rear bumper doubled as an air tank.

I know it's been done tons of times. I'm 90% sure I'm going to be making a rear bumper out of iron/steel that is going to double as an air tank. It's going to be very thick and I know plenty who've done it, so the logistics of a rectangular air tank are not an issue.

But, my question is this: How much effort and money would have to go into making an automated setup with an existing 12v air compressor that constantly keeps the pressure up, and what are my main concerns going to be? I know it'd be best to make a drain plug and that I need to hard-wire the compressor to the battery. I know it needs some sort of pressure relief valve, as well as a switch to kick it on/off when the pressure is between two points. But are the kits I have stumbled across going to be worth their value, etc.?

Also, who here has fabricated rear bumpers before? I haven't even taken mine off, so I don't know how much difficulty I'm going to have making it secure (I have some shackles and the mounts for them, but want to make sure if I'm going to use it for recovery that it's not going to fail because I built it incorrectly.)

Any help is welcome.

 

Honestly, I wouldn't mess with an automated system. Just put a switch in the cab that powers up the compressor so you can just do it manually.

As far as difficulty, what experience do you have with fabricating stuff out of steel?

 

Are you going to use this rig for offroading? All I can think off is your dropping your bumper on a rock going down a ledge or something and seeing the thing blow up

 

most people mount compressors under the bed/ in the engine bay. Besides where is there room for an air tank on a rear bumper?

 

It wouldn't blow up, just leak the air really fast lol.

 

If I was going to do this I would just rig the bumper as a air tank. I guess you would just have to mount the connector piece to the bumper if I'm not mistaken?

 

If you don't have the tank pressurized it won't do anything. I typically leave my tank empty until a few minutes before I need to use it.

This is actually a pretty good idea if you have a boxed (square tube) bumper. My Armor Tech bumper is made of square tube. I don't know how good of a job Kevin did of keeping it fully sealed but it'd be a great idea.

 

@ Steve-O Good idea. I might do it. The only reason I wanted a fully automatic system was for using power tools, etc. but I suppose just having a switch would make it way less hassle to build. As far as fabricating stuff? I have years of experience with a welder, as well as trial and error If I can figure out the logistics of making it work, I can build it.

@achirdo The idea is to make the bumper completely sealed and have it as a functional air tank.

I was going to mount the compressor either in the engine bay near the cab, or behind the seat. It isn't really watertight or designed to be whatsoever, and doesn't need much room to vent heat. It'd be fine there. For wiring it up I was going to have a fuse no further than 3" from the battery and just have the wires snaked through a firewall somewhere. Location of the compressor isn't really a concern overall though.

@truckboattruck That's really neat. I'll have to look into that more. But with the idea I'm thinking of, I get really solid shackle mounts as well as a tougher bumper out of the deal. I'd also probably get a larger capacity tank.

The metal I'm working with is really thick stuff, probably 3/4"+ and is actually an old toolbar from an old piece of farm equipment. It is solid, that isn't the question.

 

well most air compressors can be set to only pressurize up to a certain pressure then turn off (actually I think they all do this). So I guess that is somewhat automated yet still very simple and reliable.

And yeah I was just making sure this isn't your first welding project . Sounds like you have it pretty figured out, can't wait to see what you come up with.

 

I would reconsider using 3/4" steel for a bumper. That's going to be a 250lb bumper.

You can purchase pressure switches depending on the max working psi of the compressor. For example, my compressors turn off at 200psi and turn back on at 165psi.

 

thanks for clarifying and x2 on the 3/4" steel! Good luck welding that stuff too lol. Stick with 1/4" at the most.

 

It may only be half inch, I'm not sure. I haven't looked at it in quite a while, I just know it's very solid lol. It's no less than 1/2" though. I suppose you'd have to see what i'm working with, but I promise you it's perfect for this application. It's the right size and shape, it's very solid, and it's free.

Like I said I just don't know the best way to go about automating a system. Ideally I'd like to be able for it to have constant power yet only kick the compressor on when the pressure is low. It'd be toggled though, obviously, in case I were leaving it for an extended period so it wouldn't drain the battery.

First and foremost I found this switch: http://www.acehardwareoutlet.com/productdetails.aspx?sku=998033790&source=GoogleBase

But beyond that I really have no experience building an air compressor setup. I already have the compressor and the tank construction begins after my current project is finished tomorrow afternoon.

 

Here is a link to pressure switches.
http://shop.air-zenith.com/pressureswitch.aspx

You will run a switched source to one end. This will be the switch you use to turn the compressor/s on. The other end will go to a relay that draws power from your battery and diverts it to your compressor/s.

Even 1/2" is over kill for a bumper unless you plan on hitting ice bergs with it. I wouldn't go any thicker than 1/4". Even that's on the upper scale of things.