Air Compressor help

[mtnbkr]

I recently picked up this air compressor at wal-mart for $22 (unadvertised sale, normally $80): http://www.toolsdirect.com/presentationpage1.cfm?pagename=productdisplay&manufacturer=Campbell%20Hausfeld&productid=FP2052&finish=NA

I knew going in that it wasn't designed for air tools other than low volume tools like grease guns, brad nailers, and small paint pens (great for inflation needs, my main need).  Anyway, I wonder if I can daisy chain this to my 10gal air tank and use it for limited air tool use.  I'd like to be able to run an impact wrench for a few seconds at a time (breaking nuts, etc) or using a standard paint gun to paint a few square feet, etc.

Will this work?  The compressor itself will deliver 1.4SCFM@90psi.  The extra tank I have is rated to 125psi.  

Chris

[K Frame]

I can't see how it will work, Chris, unless you can get the air donkey to dump a lot of air in a very short period of time, and that's partly a function of outlet size...

The air donkey isn't designed to supply large volumns of air in short periods of time as a large compressor is.

[cfabe]

You can run an air tool on that compressor, just won't be able to run it for very long. Daisy-chaining another tank will help somewhat, but you're still limited by the slow recharge rate. If you take the plastic cover off you should be able to remove the coily plastic hose and attach a normal 1/4" or preferably 3/8" air hose.

[280plus]

Yup, it'll extend your run time but also your recharge time. The only way to know for sure how much is to try it. I suspect it will put excessive wear and tear on the compressor though. It'll be running a lot.

[mtnbkr]

I can't see how it will work, Chris, unless you can get the air donkey to dump a lot of air in a very short period of time, and that's partly a function of outlet size...
The air donkey isn't designed to supply large volumns of air in short periods of time as a large compressor is.

That's part of my question, I don't know if the tools I'd be interested in really constitute a large volume use.  Besides, I'm not trying to run them for minutes at a time, just short bursts to break nuts loose, etc.  

If you take the plastic cover off you should be able to remove the coily plastic hose and attach a normal 1/4" or preferably 3/8" air hose.

Actually, the connector is exposed and of a standard thread.  That's what made me think of daisy chaining to my larger tank.  I can run a sturdy line from it's output to the input on the other tank and run my tools, etc from the output of the 10gal tank.

Are there any calculations that I could use to determine what I can run and for how long?

Chris

[K Frame]

Hum...

OK, I was under the impression that impact wrenches used a lot more air (7 to 9 SCFM) than they actually do.

A quick look at the Harbor Freight site shows that anywhere from 2.5 to 5 seems to be the average range for 3/8s to 1/2 inch impact wrenches.

That may be doable...

[erik the bold]

Are there any calculations that I could use to determine what I can run and for how long?

The formula is:  

Q=14.5 PD²
where Q is C.F.M., P is absolute pressure (gage pressure + 14.7) and D is orifice diameter in inches.

Your 10-gallon receiver tank requires 12.31 cubic feet of air to charge from 0 to 135 psi.  The 2 gallon tank requires 2.46 cubic feet, for a total of 14.77.

About 1/3 of that is usefull (around 5 scfm).  Look on the compressor to find the cubic foot output per minute, and you can calculate the re-charge time.

Yes, by all means, you can piggy back the tanks.  Make sure that the add-on tank is rated for the highest output of the compressor. I would recommend the use of hydraulic tubing and fittings for connecting the two, together to reduce pressure drop (probably 1/2")

Note that you should drain the tanks on a regular basis, because this is going to run hot, hence condensation in the tanks.

[mtnbkr]

Excellent info Erik!

The add-on tank is rated for about 10lbs lower than the compressor, but the compressor has a pressure adjustment knob for output side.  It's risky, but as long as I pay attention, I'll be fine.

One more thing...

Is there such a device that'll get an air line through a wall in clean manner?  I'd like to keep the compressor in my basement, yet use it in the garage without carrying it around.  My garage and basement share a wall.  What I envision is a wallplate on the basement side with an air inlet and outlet.  The compressor attaches to the inlet and another hose for my tools attach to the outlet.  On the other side of the wall, a single outlet is mounted.  That way, I can attach my 20ft hose and tools (or airchuck) to that wallplate and access the compressor.  The air inlet on the basement side would be threaded, but the two outlets would use quick release chucks.

Chris

[280plus]

It's risky, but as long as I pay attention, I'll be fine.

Don't forget our friend Mr Murphy...

[K Frame]

"It's risky, but as long as I pay attention, I'll be fine."

Before you burst the tank and splatter yourself all overy our garage, would you be kind enough to write me into your will as the recipient of your 6.5x55?

You can give the S&W to someone else.

[mtnbkr]

our garage

Know something I don't?

would you be kind enough to write me into your will as the recipient of your 6.5x55?

No, that's for Abby.  

Chris

[cfabe]

If you remove the cover of the pressure switch you will see a nut that can be adjusted to move the cut in/out pressures up and down. Just loosen the nut a little until it cut out pressure is below the working pressure for the secondary tank. Do this with the power disconnected, btw, terminals will probably be exposed.

[K Frame]

"Know something I don't?"

No. But I think I've proven to us both that my keyboard sucks. Note that the errant y is there, it's just in the wrong spot...

"No, that's for Abby."

I'll give it back to her in 12 years.

[erik the bold]

One more thing...

Is there such a device that'll get an air line through a wall in clean manner?  I'd like to keep the compressor in my basement, yet use it in the garage without carrying it around.

Depends on what type of wall we're talking about......

If drywall, you could maybe use one of those panels used to connect washer water hoses, removing the installed fittings and using "bulkhead" fittings.  You could also get some sheet aluminum and use on both sides of the wall.

Also,  you can use hard copper tube for installing.  1/2" size x .065 wall is rated for a bit over 1200 psi, and it won't corrode like black pipe with malleable fittings

[Lennyjoe]

I know I pretty much burned up my 5 gal maintenance free compressor using a 1/4" die grinder while porting and polishing my cylinder heads.  Got the compressor for free from a friend and it sounds like its on its last leg.  

I'd keep them seperated.  Use the small dude for airing up tires, blowing off dust and minor stuff like that.