Air compressors

[65535]

A while back I posted about air compressors. Found out belt driven oil bath compressors where the bees knees in reciprocating compressors. I ended up with a Craftsman as a gift for my 19th birthday.

That was a month ago, the motor is a bit crooked so the tech guy came out and banged on the motor mount no luck so he ordered a new one. (Thank god, I didn't want a pounded on motor.) The pounded motor works for now until the new one shows up. Hopefully the new one will be straight and run smoother.

Anyways I love adding stuff on and tinkering so here's a few things I did.

Replaced the drain valve with a ball valve on a 4" nipple and an elbow.
Replaced the quick connect outlet with a 3/8" ball valve an a universal coupler.
Replaced the stock air filter/silencer with a larger one.

If you want to quiet your compressor down slap a bigger air filter on it. It's surprising what it will do. Mine didn't need to be quieter but I wanted it to be anyways.

You're probably thinking, well jeeze you have high flow 3/8" fittings and ball valve on 1/4" feed and 1/4" termination on the end of the line, that's ridiculous overkill.

It is, but it's cheaper to get the universal couplers over good quick connects. It also lowers resistance for running air tools in the future. Less restrictive quick connects the better.


EDIT: The hose and blow gun arrived, and I made a rack at my cousins house out of steel. Still waiting on the motor and belt.

Anyways here's the eye candy (or not).

Entire unit.

Showing the back.

Closer to the filter.

New vs. Old.

Same.

Regulator ball valve and universal coupler.

Mated couplers.

Why I chose the couplers in the first place.

Ends for the 100' hose I have coming.

100' Hose and home made steel hose rack.

You can also see my Guardair quiet blow gun.

Different angle again.

 

[precisionworks]

While you're at it, you might want to consider adding an air-to-air intercooler, which dramatically lowers the temp of the air entering the tank. The cooler the air entering the tank, the more moisture condenses inside the tank, instead of going downstream to air tools or paint guns. Easy to make with a couple of compression fittings & a coil (or partial coil) of copper tubing.

More expensive compressors, like the two stage IR or Quincy, come with these. It's amazing how well this works.

 

[wquiles]

I currently have a rather "small" 20 Gallon, 5HP, oil-free compressor, and would like to get something like a 40-60 gallon unit, but I would like to know what to buy and not to buy, and why. Is a twin piston better/quieter than a single piston unit?

I also read that adding an automatic drain valve is a good idea - something like this one (although this one if probably too cheap)::
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46960

Besides totally enclosing the compressor on some sound-proof housing (which I have seen done by others), what are the other ways to make compressors quieter? Did the larger filter/muffler does much?

Any/all help appreciated

 

[65535]

I currently have a rather "small" 20 Gallon, 5HP, oil-free compressor, and would like to get something like a 40-60 gallon unit, but I would like to know what to buy and not to buy, and why. Is a twin piston better/quieter than a single piston unit?

The number of pistons isn't inherently different in performance. Generally speaking single pistons go from about 0-5CFM @ 90 psi.

Then from there you get 2-4 piston units.

If you mean 2 stage vs. single stage compressor it depends. Generally with a 2 stage you will never have an issue with low pressure drop out when running tools. As long as you get a unit that recycles above 90 psi you should be fine. I like higher pressure units just because they pack that extra buffer before cycling and before you lose power at the tool.

My unit runs 150 psi max and cycles on at 120psi.

I also read that adding an automatic drain valve is a good idea - something like this one (although this one if probably too cheap)::
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46960

You don't need an automatic valve if you are good about draining the unit yourself. They are great if you keep your compressor in the boonies and don't want to go or can't get to it to drain. No matter what a ball valve is the best drain aside from automatics.

Besides totally enclosing the compressor on some sound-proof housing (which I have seen done by others), what are the other ways to make compressors quieter? Did the larger filter/muffler does much?

Make sure you get a low RPM pump. around 700-1000 is considered low RPM. 1740 rpm motors are much quieter, but generally more expensive, not as common and draw a few more amps than a high speed motor.

The larger silencer does do well to reduce noise. You get noise from a few places.

The motor so slower is quieter.
The compressor pump itself again slower is quieter.
The air intake, unless you go with a high end pressure lubricated ($5k+ at 5HP) the valve action and stroke is loud. A larger silencer will soak that up.
The exhaust into the tank, some sound goes in there and emits out the tank wall, not much you can do about that other than wrapping your air receiver in foam.

Any/all help appreciated

I would personally recommend a Quincy QT compressor (IIRC) with a 5HP 230V motor.

If there is a better compressor out there, I don't want to know about it.

 

[darkzero]

Nice compressor!

I've got a Craftsman (stamped DeVilbiss) 20 gallon 5HP oil type compressor too. I bought it when I used to work in automotive for cheap off a buddy. I love it & it has served me well for many years. Runs my IR2131 (strongest 3/4" impact at the time) quite well even when removing stuborn axle nuts. I wish the tank was bigger for times using air sanders & cutoff wheels but I don't work on cars anymore so I can live with it.

Not sure about the latest compressors but when I got mine I noticed oil free compressors are crazy noisy compared to oil type. I've got a 1 gallon oil free pancake style compressor from HF & I hate the thing cause it's so loud! I live in a quite neighborhood & not once have my neighbors complained about compressor noise (the Craftsman) even when using it late at night & my neighbors can be complainers! If I were to buy again I would choose an oil type again. They last longer too if well maintained. Not "maintenance free" like oil free but how lazy can you be, it's just an oil change.

Most of my buddies run their compressor on the side or backyard & run a hardline into the garage. Probably the best thing you can do to cut down on noise in the garage! If I had a stand up shop style compressor & the room I would do the same!

I used to have that same auto drain kit from HF too. I forgot if it worked well or not cause I returned it since I didn't have room to fit it on my tank. It's bulky! I'm running an Amflo water seperator between the hose & regulator & it works quite well when the compressor is in constant use. I highly recommend a water seperator (not the small inline one) if you run the compressor for long periods of time.

Those larger air filter silencers actually do work quite well!

 

[65535]

Barry, it's funny you mention the after cooler, I love it maybe convert a small AC heat exchanger into an after cooler, but my issue with the copper loop exchanger is that I burned myself on the aluminum pipe today when wiping the unit down after doing some leak checking. I just don't need a big foot diameter look of copper burning hot.

You wouldn't happen to know what kind of pressure a heater core is rated to do you?

 

[darkzero]

Barry, it's funny you mention the after cooler, I love it maybe convert a small AC heat exchanger into an after cooler, but my issue with the copper loop exchanger is that I burned myself on the aluminum pipe today when wiping the unit down after doing some leak checking. I just don't need a big foot diameter look of copper burning hot.

You wouldn't happen to know what kind of pressure a heater core is rated to do you?

Slap on a Spearco Air To Liquid intercooler! :naughty: Problem solved. :laughing:

 

[KC2IXE]

As for quiet compressors - the one that is over at Dad's is fairly quiet, but done on a VERY odd way

It's a BIG pump (I think from a 5 HP) running on a 1 HP motor, and driven down with pullies so it's SLOW - as in "wacka-wacka-wacka-wacka" - we adjusted the pullies so it was only trying to draw that 1 HP at full load - not much in the way of CFMs, but you can have it right next to your workbench, and not go nuts

A friend has an old "dentists" compressor for his airbrush - you can't hear it

 

[65535]

As for quiet compressors - the one that is over at Dad's is fairly quiet, but done on a VERY odd way

It's a BIG pump (I think from a 5 HP) running on a 1 HP motor, and driven down with pullies so it's SLOW - as in "wacka-wacka-wacka-wacka" - we adjusted the pullies so it was only trying to draw that 1 HP at full load - not much in the way of CFMs, but you can have it right next to your workbench, and not go nuts

A friend has an old "dentists" compressor for his airbrush - you can't hear it

It's actaully pretty common to do that, aside from the sound factor, it will last just about forever running that slow.

 

[KC2IXE]

Well, that one was a used pump, and has an addition 30+ years on it since we set it up - of course, the last 2 decades, it's been run maybe 1/month for an hour or so (maybe 5 minutes of actual pump time per run)

 

[wquiles]

The Quincy is too rich for my budget. I was looking at the $400-600 range at the most. Something like this for example:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=55995

I am in no hurry since my 20 gal DeVilbiss is still working fine, but I definitely want to start looking for something better and larger

Will

 

[StrikerDown]

I have a 30+ year old 1 HP compressor bought from Monkey Wards! It has outlasted the store! Oh and I even changed the oil in it for the first time about 2 months ago! the oil still looked good... big surprise! I built 1 car ground up and in addition I have done lots of die grinding, drilling spray painting, a little sand/bead blasting, etc. It did burn up the original motor come to think of it about 20 years ago, put in a 2 hp same RPM.

I think you will be very happy with your Craftsman when you get the one with the aligned pulleys, it looks gorgeous!

 

[choffman]

This may be more than you are looking for but I would recommend Eaton compressors.

http://www.eatoncompressor.com/catalog/item/504747/172983.htm

Big money, but a lifetime compressor.

 

[65535]

You guys will never guess the replacement cost of a motor for that compressor.

I have a warranty so I'm covered, but the receipt showed $430 for the motor, $212 additional for the 1-2 hour replacement labor.

If the new one isn't straight I'm drilling out the holes installing plastic bushings to reduce metal-metal contact and line er up.

 

[65535]

I've heard mixed things about Eaton, they are a good compressor most pumps are made in China, but I hear the QC is done in the US during assembly and the quality is there, still made in China though.

 

[StrikerDown]

You guys will never guess the replacement cost of a motor for that compressor.

I have a warranty so I'm covered, but the receipt showed $430 for the motor, $212 additional for the 1-2 hour replacement labor.

If the new one isn't straight I'm drilling out the holes installing plastic bushings to reduce metal-metal contact and line er up.

You probably didn't pay that much for the whole compressor did you?

I'm glad I bought that motor 20 some years ago then! I do seem to remember that it was kinda expensive though... long before eBay!

Where did you get the Air filter?

 

[65535]

Air filter was purchased through Granger, the motor is a 1.8 HP (2HP) 3450rpm capacitor start motor with weld on mount.

Compressor runs for around $400-$500 new. So I don't understand the motor cost at all.

Realistically that motor should cost $150-200 new.

 

[StrikerDown]

Air filter was purchased through Granger, the motor is a 1.8 HP (2HP) 3450rpm capacitor start motor with weld on mount.

Compressor runs for around $400-$500 new. So I don't understand the motor cost at all.

Realistically that motor should cost $150-200 new.

I think that sometimes they do that as an incentive for you to want to buy an extended service contract because the repairs are so expensive!

I don't buy service contracts on hardly anything.

 

[precisionworks]

what kind of pressure a heater core is rated

Around 15 psi, IIRC.

Quincy QT compressor (IIRC) with a 5HP 230V motor

I have one Quincy QT & a pair of Home Depot Husky models. The Quincy is ten times the compressor of the Husky. Quincy keeps a database of all units purchased through a dealer, and can track a pump from birth to death ... except they seem to never die. I had issues with head gasket failures on mine, and they sent replacement parts, well after the warranty had expired, until they fixed the problem. Awesome service.

The IR T30 is another nice unit.

I would recommend Eaton compressors.

+1

One of my customers had an Eaton recip, running 12 to 14 hours per day, 6 days a week. Eaton said that they would kill the pump & they did. Eaton replaced the pump under warranty. Customer finally bought the correct unit, an Eaton rotary screw.

If you want a quiet unit, look at a rotary screw. Eaton, Kaiser, IR, Quincy, et al, make smaller units. Around $5k buys a nice setup, good for a lifetime of use.

 

[choffman]

I've heard mixed things about Eaton, they are a good compressor most pumps are made in China, but I hear the QC is done in the US during assembly and the quality is there, still made in China though.

Here is a write up from the website about being MIC.

Product Disclosure Form

To compare "apples to apples" on where a product is made can be very challenging. We have attached a Product Disclosure Form that you can print off and take to your air compressor providers to have them complete so you will know where the product and its components are manufactured. Just because you see the American Flag sticker on the front of the unit does not mean it was actually made in the USA. There are many factors that you need to be aware of before purchasing a unit. 1. Where the parts were manufactured, 2. Warranty, 3. What are the replacement parts going to cost for the unit you are purchasing? We have seen 5 HP compressor pumps that are over $1,000.00 for a rebuild kit. We use international compressor pumps built in one of our own factories. This is why you see "EATON" in our castings. One out of every 100 compressors is built in the USA. We strive to give Americans jobs (the majority of our piston-type unit's components are made here in the USA) but have to also keep PREMIUM quality at a reasonable price with a 5-YEAR BUMPER-TO BUMPER Warranty on all parts - NOT PRO-RATED!!! Our quality and price is the best on the market. Our goal it to beat our competition name-brand and non-name brand. Have your compressor company complete this form and if you have any questions about what they have filled out on the form, you can call me personally.
Starting October 28th, 2008, We are putting an American flag sticker on the items that are made in the USA. For example, our tanks are made in the USA, So we have placed an American Flag Sticker on the tank that states this tank is manufactured in the USA. These stickers will be placed on every item that is made in the USA. This gives the consumer a clear direction when purchasing our compressor on how much of the complete unit in made in the USA.
I can only think of 2 companies that build compressors here in the USA.
Ultimately, we encourage our customers and potential customers to compare our product to any product in the industry. You the buyer, should know exactly what you are buying and from who you are buying it from.
[FONT=&quot]Sincere Regards,
[FONT=&quot] [/FONT]
[FONT=&quot]Matt Cain[/FONT]
[FONT=&quot]President/CEO[/FONT]
[/FONT]http://www.eatoncompressor.com/eatoncompressor.html

Regardless, they are good machines IMHO if you have the $$$$.