Compressor / Air Tools help

[Raf99]

If I have a 5 gallon compressor that will do 135 PSI max with 4.8 CFM at 40 PSI / 3.5 CFM at 90PSI, and a gun that will do 420ft-lb tq. but requires SCFM of 3.7 @ 90 PSI.....

Assuming I want to max the tool out, what is the maximum setting I can/should set the tool PSI on the tank for this setup? I had always used 90, thinking that the tank can only push max 90PSI at 3.5CFM for this tool but would setting it to 130PSI do anything here?


To summarize:

Tank:
135 PSI max
4.8CFM @ 40PSI
3.5CFM @ 90PSI

Impact Gun:
420ft-lb torque
needs 3.7 SCFM @ 90PSI

[Flip-Eye]

I would tend to think you'll be maxing that little 5 gallon out rather quickly.

If your already over taxing it by running a tool requiring more CFM that your compressor puts out and/or if you do actually hit pressure required to get anywhere near the 425 ft/lbs your anticipating, it'll probably only be for a few seconds.

Is it running an impact gun?

[Raf99]

I would tend to think you'll be maxing that little 5 gallon out rather quickly.

If your already over taxing it by running a tool requiring more CFM that your compressor puts out and/or if you do actually hit pressure required to get anywhere near the 425 ft/lbs your anticipating, it'll probably only be for a few seconds.

Is it running an impact gun?

Yes.

[cp[mike]]

mine is set to 120.............. hasnt blown up yet, but I don't recommend it. I also can't see how a 5 gallon will have enough volume, but if you let it fill up all the way, you might be able to get a quick blast out of it to break a bolt loose. it probably won't do much if you try to use it while its running/refilling.

also make sure your air lines are good... some of the ones out there are TINY diameter... i ran 1/2" air hose and got the special quick-disconnect fittings from Harbor Freight that have extra wide openings thru the center, so that none of the fittings are creating a bottleneck.

[Raf99]

I hear ya. & I'm noticing to get past 3.7SCM @ 90PSI you need a pretty big upgrade for the tank! Lot's of tanks 5, 10, 15, 20 gallon but they all push the same SCM. Not until you get into the $400+ tanks that you see SCM that can be used for good impact guns.

Even 500ft-lb tq. require 3.9SCM @90PSI, and then you're looking at some expensive tanks.

Gone to try 120

[h22sparkle]

Most good tanks will run you about 300 or more. If its an 8 gallon your better off breaking the bolt loose then go from there

[Flip-Eye]

Tanks that small are typically used for inflating roofing nail guns, other small tools requiring not much air.

If you got enough pressure out of that tank, you'd only have a window of a few seconds at peak pressure to break the bolt loose.

If your not breaking it loose in that small window, it ain't coming loose!

[jst_4_kiks]

Check craigslist for a used taller/larger capacity compressor. I got mine free (vertical craftsman 30 gallon oil less) from my old work because they upgraded to a larger quieter machine. Handles my air usage fine. Deals online & black friday & xmas time. Home depot, lowes, sears, tractor supply... all good units for personal use.

[Raf99]

Went with a 4ft. steel pipe instead, and......... dam.




The bolt I'm trying to remove is an axle nut/bolt

[cp[mike]]

i would recommend using CRAFTSMAN breaker bars on that nut. you may even break a couple more on it before it comes loose, being able to stop at the local sears and get a new one helps. Or go for a 3/4" drive :P BTW, the air gun wasn't going to take that nut off, either. My 30 gal doesnt budge it, sometimes you can't beat sheer leverage. You did make sure to un-stake it first, right?

[GhostAccord]

A little bit of heat (BurnzOmatic torch) and mechanical leverage, with a quality strong bar (Craftsman is what I use), is really all it takes to get those old axle nuts to break loose.

[Raf99]

i would recommend using CRAFTSMAN breaker bars on that nut. you may even break a couple more on it before it comes loose, being able to stop at the local sears and get a new one helps. Or go for a 3/4" drive :P BTW, the air gun wasn't going to take that nut off, either. My 30 gal doesnt budge it, sometimes you can't beat sheer leverage. You did make sure to un-stake it first, right?

Please......... :P
Ya, thinking of going and buying this - http://princessauto.com/en/detail/pr...ch/A-p8340507e

A little bit of heat (BurnzOmatic torch) and mechanical leverage, with a quality strong bar (Craftsman is what I use), is really all it takes to get those old axle nuts to break loose.

Ya, going to heat it next time before I put another break bar on it or before I take a gun to it. I was using some anti-seize junk.....

Just not sure what to buy since everything else failed. New electric gun (360ft-lbs tq.) or a bigger / better breaker bar?

Your suggestions?

[floored]

Kind of off topic but back when I had a cb I broke about 14 or 15 craftsman ratchets. I think I was breaking them 3 at a time and returning them to sears. after about 15 they told me they would no longer exchange them under warranty. I told the guy to watch this, and went out to loosen that nut and guess what, snapped em all. He basically told me to screw so I went over to the service area, garage door opened, puled in grabbed an impact and threw my socket one....problem solved and drove away

[Granite CB7]

I say a bigger breaker bar. I have a 1" drive setup for stubborn crank pulley bolts and axle nuts. The feel of 3/4" and/or 1" drive is so awesome over 1/2". I would personally opt for a 3/4" slide bar and not a flex handle, the slide bar is only 2 pieces really. These tend to be more direct and stronger with less moving parts. Ghost is right on point as always, heat is very important.

[lucifer1]

I have an 18v Dewalt impact and works great on axle nuts. Have not tried it on a crank bolt yet.

My cheapo air impact can't even break lug nuts loose.