OT: Portable Air Compressor

The off road guys deal with this all the time, they want to be able to air down 12.50x33x 15 tires to 10 psi for every outing, then back to something reasonable to drive on the road.

You can always try to bring along enough air in a tank but it takes a BIG tank. A lot depends on your tires but something on the order of a 30 gallon tank is about the minimum.

The little 12 volt compressors work, take a while, just die an early death. There is a slightly heavier duty version, the "Truckair" that is a bit heavier duty, it is about the minimum for doing 4 truck tires on an occasional basis. That's the one I have.

The standard rig is a truck A/C pump mounted > I know this is totally off topic for this group, but there is about a

285 70 17 for me That's roughly 11.7 X 32.7 since this truck sees road use also, but still a good size tire.

Yeah, I was thinking something big like that myself. Not a bad idea at all. Maybe 3 or 4 of the 11 gallon tanks, except they will take up a lot of room.

The ones I have had so far usually take 20 minutes to fill one tire. However, I have to admit I have always had the cheap ones. I figure you can only pull so much juice through a cigarette lighter plug, and if I found a decent one it would have to come off the battery directly.

Got a source for that? Sounds like what I am looking for. Most times and most places I go I can drive out without dropping the air. Just switch to

4wd mode and go. (positive locking front and rear differentials help a lot).

Yeah, I wasn't really thinking that was a great option on this big diesel, but threw it out there in case somebody had a great solution along those lines.

Thanks. Some great starting points in this reply.

I'm sure there are a lot more expensive and probably long-lived compressors out there, but HF has 2 models of better-quality 12v compressors, one works off the regular lighter plug, the other has to be connected directly to the battery. The one with the battery clips may be the one of interest for your application. I've got the lighter- powered one, I've inflated almost flat tires in about 4-5 minutes. Both are all-metal construction with no plastic shrouding, blinky lights, sirens or other non-compressor items attached. I've no idea how durable they are, but the cheapy is only a few bucks more than the all-plastic wonders, buy two, keep one for a spare. Mine came with a very nice nylon web carry case, better than the vinyl or rip-stop nylon you usually get. Something for you to check out.

As always, test it out BEFORE you need it!

I also remember a gadget that would replace one of the engine spark plugs and supply compressed air, was from the '50s or '60s and I can't imagine trying to swap out a plug with one of today's engines while it's hot.

Stan

I have a Truckair inflator too. It pumps less air than those ones that die after 3 hours, but that is exactly why Truckair lasts a lot longer. These Truckairs are not very expensive.

i

(I have it)

Again, it pumps less than competing models, but lasts a lot longer, for the same reason.

i

Do you have item numbers for those?

i

I have an onboard set-up on my response rig. It is mounted under the hood of a 97 S-Blazer. I cheated a bit and mounted it on the drivers side and it is powered off a second pulley mounted to the power steering pump.

In my case it can air up tires or power rescue tools.

For the once in a few years use it would be overkill. For that I would suggest a standard SCBA cylinder and a regulator.

27 cubic feet at either 2215 or 4500 PSI.

Actually they have two with hippo clips listed on their website. I considered those, and at 72-79 dollars they are not out of the budget at all. Just didn't want to spend it if they didn't work. I think I may stop by the store today and take a look.

Buy two. You sound like me. Always have a spare. If you find something you really like and can afford it buy five. (My favorite popper rod I did this with and they don't make it anymore. I still have four left.)

Sounds like it will fit right behind the seat along with my locker bar, jack, shovel, cables, tow strap, etc

I was just thinking if I buy one I'ld head for the shop and flatten a couple tires to see how it works.

I think I have one in the emergency road kit in the saddlebag of my wife's Harley. I'm afraid it wouldn't work very well on my diesel truck.

Bob La Londe

those, and at 72-79

if they didn't work.

really like and can

make it anymore. I

shovel, cables, tow

tires to see how it

Harley. I'm afraid it

I have one of these.

great. Just be sure to run the engine while operating, as it will suck a battery down quickly. It's often on sale for $50, then apply a 20% off coupon for a better deal........Paul

I looked at that one last night.

So can you tell me what might be the difference between these two?

and

I mean other than 3 dollars. LOL.

Bob La Londe

> Works great. Just be sure to run the engine while operating, as it will suck a battery down

93186 is real shiny chrome. :-) Otherwise, they are about the same. The hose on 93186 plugs directly into the compressor and the 66399 has a pigtail. I don't think the 66399 was available when I bought mine. Another thing to watch out for, is they get hot enough to burn you if run for a long time....Paul

Re the 20% HF coupon. Here is one that's good until Nov. This is from Popular Mechanics. Some people believe it's not right to use a copy (black and white is fine at my HF). My HF had no problem with it and even gave it back to me to use again.....Paul

Paintball sized CO2 cylinder & regulator.

On Mon, 13 Jul 2009 10:10:18 -0500, the infamous Ignoramus20849 scrawled the following:

And on the same page, a Programmable Digital Tire Gauge. Crikey, what are we coming to as a race?

-- Mistrust the man who finds everything good, the man who finds everything evil, and still more the man who is indifferent to everything. -- Johann K. Lavater

So -- does that translate into it living longer to pump the same total air as the shorter-lived but faster ones.

Enjoy, DoN.

[ ... ]

The color, and the length of the coiled nylon air line. (8 feet more for the first one).

Accessories for filling sports balls (footballs, soccer balls, etc), and inflatable mattresses.

4" difference in the power cable length. 0.1 pounds total weight.

The second ones has a little over twice the total volume. (Hard to tell how much of that is significant, but comparing the apparent size of the compressor itself vs the size of the battery clips, I think that the volume comparison may be a reasonable measure. This makes me wonder why the difference in weight is so small.

They both claim to fill (or inflate) a tire (of unspecified size, and to an unspecified pressure) in three minutes. :-)

Perhaps it might make sense to track down one of the compressors used for air brakes in serious freight trucks, and see whether it could be mounted someplace out of sight, leaving access just to the power switch (on the dash?) and the air fitting. What pressure do those run at? I'll bet that they would have a much longer service life, and you might even be able to set up a tank to store pressure while you are driving so some air is available at short notice.

Enjoy, DoN.

No, it is supposed to last for a very long time, as in many years. Over its life time, it will pump much more air than the cheaper ones.

i

Both Gast and Thomas make some "real" 12V DC motor driven close coupled oil-free piston compressors in the 1/4 - 1/3 - 1/2 - 3/4 HP range, and they will do 100 - 125 PSI. Check the Grainger catalog, they list some of them.

But they are not cheap, you'll pay $300 to $800 for a new one, depending on size. But still less than the production models with a starter motor and an oil-lube compressor, or the "On Board Air" systems that hang a screw compressor off the transmission PTO - and if you don't have a PTO you need to add one...

The Harbor Freight ones look OK, but I would not use them on anything "Mission Critical". You don't want a 20-mile hike out to civilization if you get a flat tire and the compressor craps out.

Read the charts and decide what your max pressure needs are, then the CFM, then the space to mount it under the hood.

You can probably hook up a set of jumper cables, a 10' hose and chuck, and make legs with rubber feet if you need Portable.

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That is a good idea. I was actually considering adding a small pressure tank somewhere to whatever I do.