HF 21 gallon air compressor.

[hornedfrog1985]

Anyone have this unit? Would it supply enough power to loosen, say, an axle nut, or something along those lines? I would probably only use it maybe once a month, so I don't want to spend a ton on a compressor.

http://www.harborfreight.com/25-hp-...-cast-iron-vertical-air-compressor-67847.html

I would hardly ever need it for something like and Axle nut, but if it happened I would want it to be able to do it. MOST of the time I would just be doing suspension work, brakes, little odd jobs like that.

 

[Homoudont]

I have the #94667 model and have that review posted in the harbor freight pass fail thread.

The only complaint I have besides the wheels is that it's very loud. But I use it so infrequently it's not a big deal.

 

[timtim2008]

i have this, so far so good

 

[Cryptic1911]

I have one of those, and an Earthquake 1/2" impact, and it seems pretty nice. I got it a few months ago for $139, and it was worth every penny. Once the tank is full of air, the only thing limiting the air flow is the regulator, line and your fittings. The cfm of the pump doesn't come into play until the tank is empty and you're using tools while the pump is going. I did however get a nice flexzilla hose, and some milton v style fittings and chucks, so it flows well from one end to the other. It was ok before too, just the fittings and hose we had leaky as hell. The milton v style fittings flow much better though

 

[hornedfrog1985]

I have one of those, and an Earthquake 1/2" impact, and it seems pretty nice. I got it a few months ago for $139, and it was worth every penny. Once the tank is full of air, the only thing limiting the air flow is the regulator, line and your fittings. The cfm of the pump doesn't come into play until the tank is empty and you're using tools while the pump is going. I did however get a nice flexzilla hose, and some milton v style fittings and chucks, so it flows well from one end to the other. It was ok before too, just the fittings and hose we had leaky as hell. The milton v style fittings flow much better though

Do they sell the Milton fittings at HF? I was actually thinking about that exact combo with the 1/2" earthquake. Do you think it would take an axle nut off, or something like that? Also, if I ran the earthquake 3/8" air ratchet that requires 6scfm would that even work on this compressor since it's only rated at 4.7cfm? Those are the only two tools I would use for the most part.

 

[Cryptic1911]

No, they don't sell the milton fittings at HF. They have some chinese fittings that leak. I got mine from here http://www.toolsource.com/vstyle-hiflow-brass-coupler-female-p-106755.html

What's the axle bolt torqued to? I don't think you'd have a problem. Mine seems to work damn good, zips off lugnuts like nothing. I'm sure the axle bolts are cranked on more, but it should be no problem

Anyways, about the cfm's, What I was getting at was that if you fill the tank and the pump shuts off at 125psi, and the regulator is set at 100psi, then you have 100psi of air flowing at whatever cfm your 3/8" line, and 1/4" npt fittings will allow. The pump only pumps 4.7cfm when it's running, so obviously if you have an empty tank, you aren't going to have full power until the tank pumps up to the shutoff (125psi in this case). So basically the only thing that limits the flow between the tank and your air tool is your regulator, fittings, and air line. An impact gun should work just as well on this compressor vs a larger compressor (when running from the air supply in the tank). Only thing is that the larger the tank, the longer it can power the air tool before the pump turns back on (and pumps 4.7cfm in our case)

 

[hornedfrog1985]

Ohhhhhhhhhhhh. It is all starting to make sense. I finally get what I'm looking at in the specs. Thank you. for all the help.

So I can actually set the PSI higher than the tool even requires for more torque? Will I damage the tool if I do this? That would obviously drain the tank faster as well then.

 

[chewy7]

No, they don't sell the milton fittings at HF. They have some chinese fittings that leak. I got mine from here http://www.toolsource.com/vstyle-hiflow-brass-coupler-female-p-106755.html

What's the axle bolt torqued to? I don't think you'd have a problem. Mine seems to work damn good, zips off lugnuts like nothing. I'm sure the axle bolts are cranked on more, but it should be no problem

Anyways, about the cfm's, What I was getting at was that if you fill the tank and the pump shuts off at 125psi, and the regulator is set at 100psi, then you have 100psi of air flowing at whatever cfm your 3/8" line, and 1/4" npt fittings will allow. The pump only pumps 4.7cfm when it's running, so obviously if you have an empty tank, you aren't going to have full power until the tank pumps up to the shutoff (125psi in this case). So basically the only thing that limits the flow between the tank and your air tool is your regulator, fittings, and air line. An impact gun should work just as well on this compressor vs a larger compressor (when running from the air supply in the tank). Only thing is that the larger the tank, the longer it can power the air tool before the pump turns back on (and pumps 4.7cfm in our case)

you still might only get 70 psi or so at the tool while its in operation to account for pressure loss. you want 90 psi at the tool while its in use . so set the regulator at like 120 to account for the pressure loss through your hose.

 

[Cryptic1911]

The tank PSI is always going to be higher. A big compressor will pump up to like 175 psi, but you'd keep your regulator at like whatever the air tool needs. The 175psi on the tank side just gives you more stored capacity before you run out.. it doesn't really do all of the work. the CFM is what is going to produce the torque.

 

[SpiderGearsMan]

add air tanks for more scfm , don't think I would get the hf ones though , could be a bomb

 

[chewy7]

when the air is actually flowing you want 90p p.s.i. right before the tool but after the hose. more pressure in tank equals more capacity.

 

[chewy7]

If the regulator is set at 90, you might only get 60-70 p.s.i. at the tool while its being used. That would be too low and the tools' performance will **** big time.

 

[hornedfrog1985]

So if I had this compressor and its max PSI is 125 am I going to be running the compressor constantly just to get little spurts off it? Would I even be able to set it at say.... 110 psi so the tool sees ~90psi?

 

[Cryptic1911]

the hf earthquake 1/2" specs say it requires 90psi, so whatever you buy should be ok after any pressure loss, though if you keep to reasonable lengths of hose, it won't be too bad. You don't need 300ft of hose if you only use 15-30ft anyways. The shorter it is, the less pressure loss you'll have

 

[fitz11]

I have one of these with a 25 gallon tank plumbed with it. It takes a bit to fill both tanks but has worked for everything I can throw at it. For the money you can't go wrong.

 

[Handyman163]

I have the older model 94667 referenced above, and it does all I need it to do with the 1/2" earthquake gun. I will say that the first thing I did was remove the regulator altogether, and here's why. I set the shutoff so that the pump shuts off at 120psi and kicks on at 90psi. When there is 120psi in the tank, with a pressure gauge mounted just before the impact wrench, as soon as you pull the trigger on the wrench, pressure drops to a perfect 90psi when using a 50' 3/8" goodyear air hose. This is using their hi-flow air couplers. So, I removed the regulator and mounted couplers on it so I could plumb it in if needed (brad nailer, etc), but the compressor is perfect with no regulator on it since the hose and fittings regulate it to 90 anyway.

The Earthquake gun is AWESOME. Worlds better then the cheap impact wrenches sold at HF and elsewhere. It zips lugnuts off like lightening (torqued to 110 ft/lb.), and I set it on setting 3 of 6 to put them back on, and that puts them just shy of clicking the torque wrench at 110 ft/lb. The gun is heavy though, but it's quick, so you won't be holding it long.

As for air usage, I can remove two wheels and re-install them for a brake job or tire-rotation on my Chevy Truck before the compressor kicks on if I'm quick about it. Then the compressor kicks on for 2 minutes or so. It's LOUD, but it's does all I need it to do.

I also swapped off the air shutoff to a 1/4" brass ball valve (at HF) since internally it is much larger than the one that came on it. I didn't notice much difference, but it certainly didn't hurt. Then, I installed a splitter to give the compressor 2 female hose couplers. This, in addition to the 1/2" air-hose supply line I made to run a hose reel and hookup for the bench on the opposite side of the garage, gives me air in three places and adds to the capacity of the system.

Here are some pictures before the shutoff conversion. The second photo is a comparison from the standard 1/4" air hose coupler and the hi-flow HF ones. The Hi-flow have the same internal size as 3/8" (roughly) connectors and are threaded for 1/4" hookups. The third photo shows the tee I made to measure pressure at the end of the hose just before the tool.

 

[bsaint]

Yea its a great little compressor but its going to be a bump tank for me soon.

 

[Uncle Ben]

I've been looking to get this compressor also, so it's great to hear good things about it. I'm sure I'll want to do some of these "upgrades" also. Great info

 

[Uncle Ben]

Which would you guys recommend between the two of these? One is oiled and a little smaller, the other is oiless and 5 gallons more. They are close enough in price regardless of sales, so to me that is not a factor. I've heard that oiled compressors last longer if you take care of them, but the 26 gallon unit will have a little better capacity...

21 Gallon oiled compressor:
http://www.harborfreight.com/25-hp-21-gallon-volt-psi-cast-iron-vertical-air-compressor-67847.html

26 Gallon oiless:
http://www.harborfreight.com/18-hp-26-gallon-150-psi-oilless-air-compressor-68067.html

 

[Chrislols]

I'm picking up the 21 gallon oiled because I'm extremely impressed with the performance of it for what I need in terms of air tool work, I'm going to set it up with high quality Milton v regulators, folders etc. Although I can't comment on the performance of HF's oilless compressors

This is a GREAT buy when you can pick it up with a super coupon for $139.99 and a 25ft good year hose for $12.99

Let me know if you need a link to any of these coupons.


.02
-Chrislols

 

[Uncle Ben]

A link to the $139 coupon would be great! I already have a 50' goodyear hose, but thanks for mentioning. I also got a reel from them this month that holds up to 100' hose (hose not included) and it is only $15 this month.

Another question: if I want to go with the high-flow stuff (milton V fittings), do I need to change out all the fittings, such as the air regular (change out the one that comes on the compressor), the quick connector, and all the male fitting on all my air tools?

 

[Chrislols]

It's all personal preference at that point really, I'll probably pick up a few male end fittings since they're relatively cheap, and the female quick connect adapters, but in terms of changing your regulator, I'm sure it COULD help be more precise and effiencent in air regulations and psi etc, but I'M going to wait before doing that because my pockets are relatively cheap.

 

[pipsters]

For a 125PSI outlet pressure (initially) I would completely skip the regulator. Use an adapter to plug the 50' hose directly into the compressor outlet and then use a hi-flo quick disconnect at the end of the 50' hose to plug tools into. My regulator when set at 120 PSI drops to around 90 instantly when I pull the trigger. For impact use I have a dedicated 25' hose that comes straight off and I dial in 120-125 psi at the regulator. I too have the Earthquake (new version, but have owned the old), it's a great gun and will pretty much do everything you will need it to do.

 

[neonnblack]

Uncle ben go with the oiled less noise, and that is a good compressor. I have had the older style red one outside for about 4 years now, original oil. Starts in 15 degrees or 100 degrees still no issues. I just used it last weekend doing some engine work on my car with a cheap HF 3/8 air ratchet, worked great. It is a little noisy but thats alright with me for the price i paid.

 

[Cryptic1911]

yeah, ours is still going strong.. bit loud, but it works great for the price

 

[hypertek]

I know this thread is a bit old, but has anyone mounted 2 of these 21 gals in tandem? I have one I had for a few years and it served me fine. Painted a car with it and it was huffing and puffing as far as having to wait to fill back up. But I seen mention on youtube of putting 2 pancake compressors together in tandem , and wondered if anyone tried that with these? Since these are still cheap if you already have one, and still comes out cheaper than a bigger 220v compressor.

 

[fsdogwood]

Ohhhhhhhhhhhh. It is all starting to make sense. I finally get what I'm looking at in the specs. Thank you. for all the help.

So I can actually set the PSI higher than the tool even requires for more torque? Will I damage the tool if I do this? That would obviously drain the tank faster as well then.

I think one can pretty much ignore the CFM spec for an impact, as long as
you don't hold the trigger for an extremely long time to exhaust the tank.

For setting the compressor at a higher PSI, I would take a look at the PSI
at the tool end, not the compressor end, as there should be some pressure
dropping along the hose.

I am using the mac700 with the HF twin-hammer impact, and was able to
remove 3+ Honda lug nuts before the compressor kicks in. I'd just wait
for another 10 seconds, and I can take 1 wheel off.

It's the sanding, etc., that requires continuous air flow, not the impact.
So this HF compressor or lesser one should be fine (for impact wrenching).

HTH.