School me on air compressors

[ThrottleJockey]

Or check out pawn shops.

This. Or buy the smaller one and a second tank to add on...

 

[AllenM]

Yea on second thought, pawn shops would be a good idea

 

[melensdad]

& how much HP?

I'm guessing it would be around two or three.

I'd be pretty much willing to bet that if you try to go over 2hp the compressor will require a 240v dedicated outlet, and won't run off standard 120v household current.

 

[ATOMonkey]

You can buy a tank and add that to your little compressor if you want a larger air resevoir. They're typically pretty cheap.

 

[jedi]

Guess I'm going to "hit" a pawn shop real soon.
(Like the play on words there).
-Jedi

 

[Wheezy50]

As someone already said, HF stuff can be a bit of a crapshoot. I've only had good luck, but some of my friends have not.

With that being said, i was in the same boat as you for the last few months. I needed a compressor for things around the house. Airing up tires, blowing out guns, etc. I've got some trim projects in the house, so i will be trying out a nail/brad gun soon. I wanted to get one a little bigger than i thought i'd need, hopefully i wont need to upgrade to a bigger one.

I got a 3hp, 22gal upright compressor from a freind, it came from Harbor Freight about three yrs ago. It is the standard 120v plug in, so no need for electrical upgrades to the garage. I have only used it to air up a couple tires so far, but i think it will serve all my needs well. It's the kind with oil, so hopefully i will get some years out of it. I'll be the first to admit, it's on the loud side (unless you spend big $$ they all are). It's best to turn it on and leave the garage while it fills up.

All in all, i'm happy with it so far. We'll just have to see for the long-run.

 

[ATOMonkey]

I'm going to "upgrade" my current compressor with a 2 stage oiled pump and a much bigger motor.

 

[schafe]

Oh, believe me, those large compressors are amazingly noisy too! I finally put my 80 gal. compressor in a dedicated shed in back of the garage, simply to free me from that miserably raucous partner. (It freed up some precious floor space too)

 

[ATOMonkey]

It may just be cheaper to buy a new compressor. The cheapest pump and motor are looking like $400.

Time to hit up CL. They always have good deals on used shop equipment.

 

[jeremy]

Oh, believe me, those large compressors are amazingly noisy too! I finally put my 80 gal. compressor in a dedicated shed in back of the garage, simply to free me from that miserably raucous partner. (It freed up some precious floor space too)

80 gal, that is a little bugger there...

It may just be cheaper to buy a new compressor. The cheapest pump and motor are looking like $400.

Time to hit up CL. They always have good deals on used shop equipment.

CL?!

Pray tell who is this CL...

 

[Mr Evilwrench]

I have a 5hp which is 120V. It's pretty much on its own circuit (the shed is on the same one, but that doesn't draw much current mostly).

 

[Brandon]

If you go the pawn shop route google the reviews of what ever they actually have there in the shop. And not all pawn shops are "good deals" either.

 

[Rookie]

I've got a six horse thirty gallon. It's 120v.

 

[Butch627]

All these hp ratings that the manufacturers are putting on their compressors are a joke and just marketing propaganda. There is no magic trick that anyone has that allows 5hp on a 20 amp 120 circuit. Don't bother with those magical hp claims. Look at the amp rating on the motor and the actual cfm on the unit at 90psi. The higher the amp rating the more power but it won't be over 20 amps or it won't work on typical household wiring. With a given amp rating on the motor all the pumps will put out a similar amount of air. There is no magic secret that someone puts in their compressor to get more air with a set amount of motor amperage. When you pay more you are getting a quiter more durable compressor. Oilless compressors which I recommended against usually make a little more air output than a oiled compressor with the same amp output on the motor, but I don't believe the cost savings and slightly increased output are worth the tradeoff in durability, noise, and the ability to service it.

 

[Mr Evilwrench]

That's a good point. 20A @ 120VRMS works out to 3.2somethingHP, and that assumes 100% efficiency. I do think there are different ways to define HP, like there are different ways to define audio power, so by some marketroid bogosity they may be able to justify it.

 

[jedi]

All these hp ratings that the manufacturers are putting on their compressors are a joke and just marketing propaganda. There is no magic trick that anyone has that allows 5hp on a 20 amp 120 circuit. Don't bother with those magical hp claims. Look at the amp rating on the motor and the actual cfm on the unit at 90psi. The higher the amp rating the more power but it won't be over 20 amps or it won't work on typical household wiring. With a given amp rating on the motor all the pumps will put out a similar amount of air. There is no magic secret that someone puts in their compressor to get more air with a set amount of motor amperage. When you pay more you are getting a quiter more durable compressor. Oilless compressors which I recommended against usually make a little more air output than a oiled compressor with the same amp output on the motor, but I don't believe the cost savings and slightly increased output are worth the tradeoff in durability, noise, and the ability to service it.

Thanks Butch627. Is sort of came to this same conclusion today when I stopped at Harbor Fright, Menards, and Sears. Sears was the most helpful in terms of product information and giving me a 4-1-1 on compressors. I did not talk to anyone at any of these places but sears had the most post product information and best of all had what does each item/vocabulary item mean.

Plus looks like one of the sales associated left the associated guide book out in error so I got to reading that and it gave a lot of tips on what to emphasis and why for each of their compressors.

Learned that an oiled one will last longer and is more quiet than a oilless one. I liked this one at sears:
Sears: Online department store featuring appliances, tools, fitness equipment and more

The box they have at the store comes with a 9 part accessory kit. Looks like it's a slightly different model at the store.

Harbor Freight had this one (8 gallon)
Portable Air Compressor - 2 HP, 8 Gallon, 125 PSI

& while the price is lower ($120 for unit) I did not get a good feeling for it. On the way into the store they were having a parking lot sale and they had close to 20 of these units (re-furnished sold as is) for $70. That is way too many bad units. True cost for this unit is closer to 138 once you add the oil & accessory kit (similar to what sears gives you).

Menards has this one:
6 Gallon Air Compressor at Menards

6 gallon for $130 & it has everything minus oil so its simlar to the sears one.

Needs to go online and compare like you said the CFMs to get a better comparison. Right now I'm leabing towards the 7 gal just because it's a bigger tank. But I'm not in a rush to buy one so I'll do some more research first. I think for what I want to do 10 gallons would be the max. No need for a huge tank which I can't move easily. I would rather have the portability of the unit.


Why compare the cfm on the unit at 90psi? Why 90 psi?
Thanks

-Jedi

 

[Butch627]

90 psi is what you would generally set the pressure regular at for normal use. Most manufacturers show the cfm at 90, and at 0. Some manufacturers show it at other pressures but if they do I believe they are doing so to try and mislead you because their cfm doesn't look as good as others do at 90. 2 stage compressors show cfm at higher pressures, but since your not looking at 220v there is no need to go there.

When you are shopping only by price they can shortchange you a number of ways. The compressor may be rated at 3.5cfm, but if they used a really cheap regulator it may only flow 2.5. It may only have only one quick connect fitting. The quick connects may be very cheaply made, leak and be difficult to use. If its 2 tanks, only one of them may have a sump you can drain moisture from.
A lot of cheaper compressors have really weird air filters that don't filter well and leak are around them. Ive seen foam ones that fall apart over time and get sucked inside the pump. I would never buy a compressor that doesn't use a standard easily replacable filter.
Im not saying you should buy from there, but maybe check out AAA supply across from Lowes on 41 or some other industrial tool supply place to see the features a more expensive compressor may have. Ive recently jumped across the border from Ill so I am not sure what other places nearby sell quality industrial tools. If you shop at some industrial supply places and find something you like you may be surprised on how cheaply you may find it from a reputable seller on ebay.

Myself I would scour CL and yard sales for a used one. Newer compressors are no better than one made 30 or 40 years ago that has been taken care of but there are a lot of things you need to look at when considering a used one.

Being a gun newbie I won't be buying any used guns for a very long time. If your not confident on evaluating a dirty old compressor you may be better off sticking with new.

 

[jedi]

Okay I think I have narrowed it down to these 3 after looking at Sears, Menads, Harbor Freight, Lowes, and Home Depot. Running our HF due to the quality issue that is a 50/50 if you get something that will work. Did not find anything that was comparable with the 3 below in terms of CFM and the price range I was looking at.

Listed from cheapest to most expensive.
Menards - Tool Shop
6 Gallon Air Compressor at Menards
6 Gallon
3.5CFM@90PSI
$130

Includes everything minus oil.
Not sure if it has a quick connect connector or not. Also not sure about the filter
Sadly I can't find a manual online for it.

Sears - Craftman
Sears: Online department store featuring appliances, tools, fitness equipment and more
7 Gallon
2.4CFM@90PSI
$145
manual here: http://www.manualowl.com/m/Craftsman/16639/Manual/245455
Includes everything minus oil.
Does have a quick connect connector.

Sears - Craftman
Sears: Online department store featuring appliances, tools, fitness equipment and more
12 Gallon
2.4CFM@90PSI
$161
Includes everything minus oil.
Does have a quick connect connector.

My concern with both of the craftman is that there are some bad reviews online on the sears website for them. Saying that they are "junk" now a days and the craftman brand is no longer any good.

Can't find any reviews about Menards. I bought a power drill from them back in 2010 and its a piece of junk so that is the only experience I have with their tools.

The craftman you can get a 2 year warranty for $34 or a 3 year for $54. Covers parts but not labor. Not sure if Menards sells a warranty I think they do.

So are these worth it?
I have checked craiglist for the past week but alas have not found anything in NWI. Some good deals in the chicagoland region especially near Naperville.

 

[Butch627]

Of the 3 you have listed I like the vertical tank model. Id be willing to bet that both craftsman units have the same components on the different tanks. The vertical tank is larger, takes up less floor space and is easier to roll around. If you do stairs it is much easier to pull up stairs than a horizontal tank. It looks like it has a real air filter that probably screws into the head. The cast iron cylinder is good.
I put synthetic compressor oil in everything I own and recommend everyone else to do so also. Regular compressor oil is basically 30wt non detergent engine oil. When its 0 degrees in the winter and you fire the compressor in the garage that compressor oil is like honey. These things don't have pumps, they have a little tang on the bottom of the connecting rod that flings oil around to lube it. It doesn't work well until the oil heats up. Ingersoll Rand sells syn compressor oil, and even extends the warranty on their compressors if you buy it for one of their branded compressors.

 

[jedi]

Thanks Butch627. I'll go back to sears and look to see if they are the same parts on those 2 compressors and if the vertical one has a real air filter. If I recall both models were on display at the one in Schereville.