Harbor Freight Tools that don't suck

[sixdogs]

Let me add to my above post regarding the standard and heavy $75 impact wrench. I know it's probably supposed to be used at 90 to 110 PSI but I have the compressor at 140-170 PSI or so and it's too much to go over to reduce it so I just let 'er rip at that PSI. I'm only an occasional user but I've done this for decades and never a problem. I actually think the HF heavy one preferred more PSI and I really took some nasty nuts off with it. If the wrench broke, so be it, but it never did. When I sold it, it worked as well or better than new and if it broke, I didn't care because I wanted a new one.

I have not done that with the new XL one but may as time moves along. It's all OK and the sun will still rise in the morning.

 

[California]

One more point about HF's compressors: Mine from 10 years ago showed its rating as CFM while their model that replaced it was rated in SCFM and showed lesser output at the same amperage draw. Like 'peak HP' vacuum cleaner ratings etc I suspect HF's CFM were claimed at some unreasonable working conditions - chilled air input, cold room, overvoltage, or something, while SCFM, Standard Cubic Ft Per Minute, has some legally valid definition that should be comparable across different vendors. Just a suspicion ....

 

[Midniteoyl]

... Also, the "max" psi of the compressor is usually meaningless. Who cares (normally), if that compressor has a max psi of 150 psi? Most tools don't need that much, and unless you're doing a lot of blowgun work that actually requires that high of psi (most of the time you're not blowgunning at that much psi anyway), then it's again, a "worthless stat" that just makes the marketing sheet look good.

The higher max psi is good for keeping a consistent psi to your higher psi tools and for using multiple tools. It also helps with cycle times of the motor/pump.

 

[Midniteoyl]

Let me add to my above post regarding the standard and heavy $75 impact wrench. I know it's probably supposed to be used at 90 to 110 PSI but I have the compressor at 140-170 PSI or so and it's too much to go over to reduce it so I just let 'er rip at that PSI. I'm only an occasional user but I've done this for decades and never a problem. I actually think the HF heavy one preferred more PSI and I really took some nasty nuts off with it. If the wrench broke, so be it, but it never did. When I sold it, it worked as well or better than new and if it broke, I didn't care because I wanted a new one.

I have not done that with the new XL one but may as time moves along. It's all OK and the sun will still rise in the morning.

Thats what they make regulators for

 

[Slowpoke Slim]

The higher max psi is good for keeping a consistent psi to your higher psi tools and for using multiple tools. It also helps with cycle times of the motor/pump.

That is incorrect. It is cfm, not psi that keeps the air supply and the compressor "ahead of" your tools. You can stay ahead of an 8 cfm tool if your output supply is 12 cfm @ 90 psi, but if your output supply is 6 cfm, it won't matter if your psi is 120-150 psi. You're tool will take down your air supply faster than your compressor can replace it.

For multiple tools, you have to add your total volume demand in cfm together, and use that to determine what kind of output compressor you need. So 2 tools that each require 8 cfm are going to require at least 16 cfm (and 20 would be better) in order to be run continuously without taking down your air supply. Increasing your line pressure to 150 psi will do nothing for you here.

If you have a 1000 gallon air tank for storage, but only have a compressor that outputs 5 cfm, a constant run tool that requires 10 cfm to operate will suck down that entire air tank if you run it long enough. Cranking the line pressure up to 200 psi will do nothing to prevent this (and probably kill the tool in the process).

 

[Slowpoke Slim]

Thats what they make regulators for

That is correct. That IS what pressure regulators are for.

 

[Midniteoyl]

One more point about HF's compressors: Mine from 10 years ago showed its rating as CFM while their model that replaced it was rated in SCFM and showed lesser output at the same amperage draw. Like 'peak HP' vacuum cleaner ratings etc I suspect HF's CFM were claimed at some unreasonable working conditions - chilled air input, cold room, overvoltage, or something, while SCFM, Standard Cubic Ft Per Minute, has some legally valid definition that should be comparable across different vendors. Just a suspicion ....

There was a lawsuit settled in 2004 for exactly that - using 'peak hp' and unrealistic atmospheric conditions to get the advertised CFM ratings. Now they must use the continuous shaft HP of the motor and a standard atmosphere of 68 deg F, 36% RH, and 14.7 psia pressure. Not that they all do that, of course. Marketing is still marketing

 

[Midniteoyl]

That is incorrect. It is cfm, not psi that keeps the air supply and the compressor "ahead of" your tools. You can stay ahead of an 8 cfm tool if your output supply is 12 cfm @ 90 psi, but if your output supply is 6 cfm, it won't matter if your psi is 120-150 psi. You're tool will take down your air supply faster than your compressor can replace it.

For multiple tools, you have to add your total volume demand in cfm together, and use that to determine what kind of output compressor you need. So 2 tools that each require 8 cfm are going to require at least 16 cfm (and 20 would be better) in order to be run continuously without taking down your air supply. Increasing your line pressure to 150 psi will do nothing for you here.

If you have a 1000 gallon air tank for storage, but only have a compressor that outputs 5 cfm, a constant run tool that requires 10 cfm to operate will suck down that entire air tank if you run it long enough. Cranking the line pressure up to 200 psi will do nothing to prevent this (and probably kill the tool in the process).

Sorry, I did simplify it. And I meant say 'the higher max psi one..'

Usually the higher 150-175 psi compressors are 2-stage and thusly rated at a higher cfm per psi.

If your tool, say a needle scaler, requires 9cfm @90psi, having a single stage 115-125psi compressor is not really gonna do you much good even if it says '9.8cfm @90PSI' (which is a real stretch, I know). Not only will that single stage not keep up with the 9cfm, it wont keep up with the 90psi either 'cause if it cant get it in, it cant compress it. Agreed?

So, to have consistent psi (and by extension, cfm, or vise-versa if you prefer) you use a 2 stage with that can deliver enough cfm above the psi you need, and with a holding pressure and cut-in pressure above what the tool needs, and use a down line regulator to feed the tool set at 90psi, and viola, consistent psi.

Thats what I meant..

 

[California]

There was a lawsuit settled in 2004 for exactly that - using 'peak hp' and unrealistic atmospheric conditions to get the advertised CFM ratings. Now they must use the continuous shaft HP of the motor and a standard atmosphere of 68 deg F, 36% RH, and 14.7 psia pressure. Not that they all do that, of course. Marketing is still marketing

Thanks, that adds specifics for something I vaguely remembered. I thought Sears was the defendant in the case I remembered but it was much earlier.

Then more recently it seemed obvious that HF (and lots of stuff from China) was rated using the same bogus ratings Sears had used.

 

[aczlan]

That is incorrect. It is cfm, not psi that keeps the air supply and the compressor "ahead of" your tools. You can stay ahead of an 8 cfm tool if your output supply is 12 cfm @ 90 psi, but if your output supply is 6 cfm, it won't matter if your psi is 120-150 psi. You're tool will take down your air supply faster than your compressor can replace it.

On the contrary, the if a compressor puts out 6cfm at 150psi, it may be able to handle 8cfm at 90psi if you run a regulator to drop the pressure.

Aaron Z