Onboard Air Research

the dude

Adventurer
great choice! I just picked one of these up from Sierra Expeditions.

What are you going to do for water proofing it? Or is it a concern? On my truck, I think it may get submerged once in a while...
 

tdesanto

Expedition Leader
the dude said:
great choice! I just picked one of these up from Sierra Expeditions.

What are you going to do for water proofing it? Or is it a concern? On my truck, I think it may get submerged once in a while...

I'm building a custom ventilated enclosure to keep it inside the back of my Montero. This will give me a flat deck with D rings to lash other gear on top.

Thus, it won't be subjected to water, so for me it's not an issue.

I don't know if submerging it is a good idea. I know that it's pretty resilient concerning water spray. You can probably plumb the air intake to a safer location.

Call George at Extreme Outback and dscuss your specific needs. I'm sure he'll help you find the right solution. He's great that way.
 

the dude

Adventurer
I would be really interested in seeing the encloser you come up with. I am going to do some research on a semi permanent/semi portable set up for my truck so I can undo/remove it if water becomes a concern.
 

tdesanto

Expedition Leader
the dude said:
I would be really interested in seeing the encloser you come up with. I am going to do some research on a semi permanent/semi portable set up for my truck so I can undo/remove it if water becomes a concern.

As soon as I tweak my drawings, I'll post them up.

Also, do a search for an Extremaire install that p1michaud did. I seem to remember that he put the whole thing in one of those Rubbermaid tough boxes, but I couldn't find the exact thread or our firewall keeps removing all the photos. I'm hoping you'll have better luck finding it.
 

jcbrandon

Explorer
Experience with a Quickair2 and 31s

I hard-mounted a Quickair2 on my 2000 Dakota shortly after I bought it new. It takes five minutes each to air the 31x10.5x15s from 15 psi to 40 psi. At the time I bought it, it was the best choice I could come up with. I did not install an air tank. The compressor has been completely reliable. But it did kill the stock Mopar battery in short order. I upgraded to an Optima redtop and have had no problems.

Now that I've upgraded to a Dodge Power Wagon with 33s I'm revisiting my onboard air questions. I can easily pull the existing system off the Dakota and install it on the Power Wagon. I figure probably about six minutes each to air up the bigger tires.

I could also get more complicated and add an air tank or two. Then maybe later, add a second compressor. But I'm not convinced the extra hardware, and plumbing, and wiring, and a pressure gauge in the cabin are all worth the additional time and expense. I haven't carried air tools in the field and don't plan to start. But that plan could change.

Any thoughts? Advice? Experiences?
 
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ntsqd

Heretic Car Camper
One advantage that having a tank may offer is the ability to seat a blown tire bead. Very few compressors can supply the large volume in a short time span needed to do this. Adding a tank could make this chore easier to do.
 

tdesanto

Expedition Leader
jcbrandon said:
I hard-mounted a Quickair2 on my 2000 Dakota shortly after I bought it new. It takes five minutes each to air the 33x10.5x15s from 15 psi to 40 psi. At the time I bought it, it was the best choice I could come up with. I did not install an air tank. The compressor has been completely reliable. But it did kill the stock Mopar battery in short order. I upgraded to an Optima redtop and have had no problems.

Now that I've upgraded to a Dodge Power Wagon with 33s I'm revisiting my onboard air questions. I can easily pull the existing system off the Dakota and install it on the Power Wagon. I figure probably about six minutes each to air up the bigger tires.

I could also get more complicated and add an air tank or two. Then maybe later, add a second compressor. But I'm not convinced the extra hardware, and plumbing, and wiring, and a pressure gauge in the cabin are all worth the additional time and expense. I haven't carried air tools in the field and don't plan to start. But that plan could change.

Any thoughts? Advice? Experiences?

Unless you plan to run an impact wrench or would like to speed up the air-up time, then I think you're fine the way you have it now.

If you wanted, adding a small tank and a second compressor would certainly speed things up a bit.
 

tdesanto

Expedition Leader
ntsqd said:
One advantage that having a tank may offer is the ability to seat a blown tire bead. Very few compressors can supply the large volume in a short time span needed to do this. Adding a tank could make this chore easier to do.

I would really like to hear from people who've done this.

Would my new system, with a 4 gallon tank, holding air at 125 PSI really accomplish this?

If so, I think I'd like to add the tools to do a valve replacement, as I've recently torn a valve. The ability to repair the tire/replace the valve would be nice.
 

ntsqd

Heretic Car Camper
tdesanto said:
I would really like to hear from people who've done this.

Would my new system, with a 4 gallon tank, holding air at 125 PSI really accomplish this?

If so, I think I'd like to add the tools to do a valve replacement, as I've recently torn a valve. The ability to repair the tire/replace the valve would be nice.
I made a really crude SW model of a 33" tire for a tire interior volume estimate and by P(1)*V(1) = P(2)*V(2) I get a residual tire pressure of ~19 psi using your tank & system numbers. That assumes no temperature change, which isn't realistic, but it was quick.
IMO that is borderline not enough. The flow rate thru your plumbing would be important. A smaller tire or a larger total tank capacity would push it more towards success.

The flip side is that unless a really good tire to rim fit, the compressor probably can't do it alone so a tank in the system can't hurt.
And, all of this ignores the various tricks employable to get the bead(s) closer to seating prior to inflation.
 

madizell

Explorer
You can seat a tire bead with a hand pump if you have proper preparation and a clean tire and rim to work with, so having reserve air isn't really to seat the tire as much as to compensate for contamination of the bead, lack of proper tools on the trail, and so on. Carry a ratchet strap and use it around the circumference of the tire to expand the tire onto both beads so that you have rubber to rim contact both ways, make sure the bead surface is clean and lubricated, and it will take very little reserve air to get the tire to seat. Problems arise when you can't get contact all around and have a slow leak somewhere on the bead which you can't find or can't defeat. At that point, if you don't have that volume reserve to swell the sidewalls, you can pump all day without seating the tire.
 

tdesanto

Expedition Leader
madizell said:
You can seat a tire bead with a hand pump if you have proper preparation and a clean tire and rim to work with, so having reserve air isn't really to seat the tire as much as to compensate for contamination of the bead, lack of proper tools on the trail, and so on. Carry a ratchet strap and use it around the circumference of the tire to expand the tire onto both beads so that you have rubber to rim contact both ways, make sure the bead surface is clean and lubricated, and it will take very little reserve air to get the tire to seat. Problems arise when you can't get contact all around and have a slow leak somewhere on the bead which you can't find or can't defeat. At that point, if you don't have that volume reserve to swell the sidewalls, you can pump all day without seating the tire.

Greg,

Thank you. You're a huge help as always. That gives me some confidence that I could do this in the field. Besides, if I've really torn a valve and it needs to be replaced, what do I have to lose?

Ratchet strap? Got plenty of those too.

To lubricate the bead, I usually see the tire techs using soapy water, am I interpreting that right? Would it really be as easy as some soap and water?
 

ntsqd

Heretic Car Camper
My comments above were based on not needing to employ any of the common methods sometimes needed to get the tire's bead closer to the rim.
tdesanto said:
To lubricate the bead, I usually see the tire techs using soapy water, am I interpreting that right? Would it really be as easy as some soap and water?
Yes.
Whole point is some liquid with a high surface tension to bridge the gap and form a temporary seal. Soapy water does that and isn't harmful to the tire rubber. In a pinch you could use gear lube, engine oil or something like those. Not sure what they will do to the rubber, but you can deal with that when you get out of the out-back as what ever it might do won't happen too fast.
On larger rims a partly to fully inflated bicycle tube combined with a soapy water etc. can be used to bridge a larger gap.
 

madizell

Explorer
While engine or gear lubricant will do the job, it will also leave the rim very slick, which can lead to a follow-up problem of unseating the bead on rocks or whatever. Using soapy water differs in that as soon as it dries, the rim is no longer slick and the tire stays put. Dish soap, hand soap, or whatever you have will work, and will help the bead seat firmly and evenly. Plain water will also work if you have no soap handy.

On the trail it seems it is impossible to get the bead completely clean. Plan on using more water here than you might think just to get things clean. Patience pays off as well, because it is easier to get a tire reseated without sand and such on the bead no matter how much air you have on hand, and you don't really want grit between tire and bead anyway.

Practice breaking and re-seating a bead on a spare tire in your driveway. If you just can't get it back together, you can always take it down to the local tire shop, but the practice at home helps you to understand the trouble and force needed so that if you need to do this on the trail, it will make more sense, and you will have a greater confidence in getting the job done. Anyway, don't panic if you unseat a tire on the trail. It might be tedious and you will perhaps need to take the wheel off the vehicle to work on it handily, but you can always get it back together as long as you have an air source and a few tools.
 

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