[weirdbeard]

We let the trusty Porter cable 60gal 7 horse air compressor run out of oil at work. We build cabinets a furniture and used this compressor mostly for finishing.
While spraying the pump locked up and tripped the motors lil breaker. You can still turn the big pump pulley by hand but it is real hard.
The boss man did not want to fool with fixing it and bought a big C.H. 80gal.
Now I could probably buy this old one off him.
What should I pay for it? I mean this it probably only a $400 compressor new right? So what is it worth now? I don't want to pay to much and I am not trying to rip him off either.. Or am I?

[matt167]

give $150 or so... HF's cheapest 60 gal compressor is $399. just as an example.. Porter Cable is more expensive than that

[HalfOunce]

20bux or just ask him what he wants for it.

[oldred]

If you can get it for $100 or so then buy a pump at HF for about $90 for the 3 HP version you should be OK. You are right you could buy that thing new for about $400. HF also has a bigger V-type pump that is for 5 HP or more but you could slow it down a bit and it should work fine with your 3 1/2 Horse power 7 HP motor.

[boatbob2]

hi,i bought the small air comp pump from H.F.,it locked up in about 3 days,went back and got another one,it lasted about 2 weeks,then when it locked up,it broke the flywheel (belt part) then i went back and got my money back,DO NOT buy a pump from H.F. THEY ARE JUNK...

[OneMoreTime]

H'mmm I have one the V-twin single stage pumps from HF and it is working fine for me..have it set to shut off at about 100-105 psi and works fine...gotta check the oil on those as they are shipped dry..

Sam

[oldred]

I know of a couple of the HF V-type pumps and they have been working really good, both have been geared down to run slower with a 3 HP motor. I have never actually seen one of the small pumps for the 3 HP motor so I was basing it on the V-type but it sounds like that was some REALLY bad advice! Surplus Center has a good 3 HP pump (Devilbiss) for $90 that is made in Italy and these are good pumps however they have a rather large pulley/fan and requires a pulley change on the motor to get the speed right and most of the time the safety guard will no longer fit, other than that they are very well made and should last a long time. I actually have one of those things sitting in my garage right now that was ordered for a guy who has not picked it up yet, it is to be coupled to a hydraulic motor that will be run from a truck hydraulic system on a small service truck.


http://www.surpluscenter.com/item.as...-1761&catname=

[weirdbeard]

Wow Oldred that is a really cheap pump. 13+ cfm for $99 bucks is nice.
Do you guys think that the locked up pump on the compressor could be repaired? I mean I have never messed with one, but it seems like you could hone the cylinder walls and replace the rings (are there rings?) and it might work again.
Worse case I pay $150 for it and get that $99 pump..$250= happiness.
And yeah I don't know where they get the HP power #s from for these things. I have a 25gal compressor that says it is 5 HP. I have a shop vac that says 5HP. The drum sander at work is 5 HP and the motor is a huge 100lb monster that would take your arm off. This lil compressor motor says 7HP. I don't get it. That is another story I guess.

[matt167]

Originally Posted by weirdbeard

Wow Oldred that is a really cheap pump. 13+ cfm for $99 bucks is nice.
Do you guys think that the locked up pump on the compressor could be repaired? I mean I have never messed with one, but it seems like you could hone the cylinder walls and replace the rings (are there rings?) and it might work again.
Worse case I pay $150 for it and get that $99 pump..$250= happiness.
And yeah I don't know where they get the HP power #s from for these things. I have a 25gal compressor that says it is 5 HP. I have a shop vac that says 5HP. The drum sander at work is 5 HP and the motor is a huge 100lb monster that would take your arm off. This lil compressor motor says 7HP. I don't get it. That is another story I guess.

they use brake HP, and not running hp, to overrate a lot of compressor motors.. you figure the true hp out from the wattage..

[oldred]

Originally Posted by matt167

you figure the true hp out from the wattage..

That's about the only way to get a real idea of power output and even that will vary from motor to motor. For instance you will find 5 HP motors (real ones that is) rated from around 23 AMPs to 29 AMPs but I would bet against 100 to 1 odds that the 7 HP motor on that thing is rated no more than 16 AMPs and most likely 15. If you can find that same motor (probably an Emerson or Century) on the shelf somewhere it will almost certainly be sold as a 3 HP.

[oldred]

Originally Posted by weirdbeard

that is a really cheap pump. 13+ cfm for $99 bucks is nice.

It can be hard to find a pump that size and when you do they usually cost so much it would be better to just buy a compressor than give $150 for a used one then another $175 or so for a new pump, you wouldn't save enough to make it worth while so that's the reason I mentioned the HF pump.The V-type HF pump seems like it is OK but I should not have assumed that just because it may be OK the other one would be also. The pump from Surplus Center I know first hand is a good one and the price is certainly right but it may be a bit of trouble to set up because of the pulley size. They used the large pulley to get enough air flow over the thing for cooling so even if you had a smaller one that would fit it would not work because of the air flow. This however is a minor problem and you would simply need a pulley of the proper size on the motor to reduce the motor RPM to 1000 RPM on the pump then everything would work just fine.

[Shelby1]

Originally Posted by weirdbeard

Wow Oldred that is a really cheap pump. 13+ cfm for $99 bucks is nice.
Do you guys think that the locked up pump on the compressor could be repaired? I mean I have never messed with one, but it seems like you could hone the cylinder walls and replace the rings (are there rings?) and it might work again.
Worse case I pay $150 for it and get that $99 pump..$250= happiness.
And yeah I don't know where they get the HP power #s from for these things. I have a 25gal compressor that says it is 5 HP. I have a shop vac that says 5HP. The drum sander at work is 5 HP and the motor is a huge 100lb monster that would take your arm off. This lil compressor motor says 7HP. I don't get it. That is another story I guess.

The horsepower ratings on is generally based on the rpm that they work at most,all work type motors(except vacs) turn at 1750 rpms, most all air compressor's turn 3450 because the compressor is more efficient at that speed( can supply it's rated air output)so the compressor motor can be smaller in size with a higher hp output.
On the compressor, if it turns hard ,there are two things that are a deal killer as far as rebuilding it goes, scored cly walls and/or scored crank.There are rebuild kits for most brand name compressors but if it's "Chinaware" you'l have to toss it and find a replacement. When you pull it down( if you decide to fix it)pay close attention when you pull the head and look at how the reed valves are set up so they can be put back in the same way they came out. Other than that all the rest is pretty much straight forward.


Good Luck
Kenny

[weirdbeard]

The surplus center pump pulley looks very much like the pulley on the Porter cable. I would guess from memory maybe its a 10" or 11".
If I buy this thing I will tear down the pump. Even if I cannot rebuild it thats always a good way to learn something.

Man the thought of a big fat air compressor just makes me happy. Maybe its just me..

[oldred]

The flywheel on the very common Campbell Hausfeld type compressors usually measures about 10" and the one on the Surplus center pump is 14 1/2".

[jaguarxk120]

First I would ask what he's going to do with the compressor. You may get it for the taking! If not you have the option of throwing money at him.

Second it depends who made the pump, Sounds like the bearings are shot. Turning stiff but still turning indicates a lower end rebuild. You can find a shop that will rebuild it or provide you with parts to do it your self.

Also the pump has a core value in it self. Look for a dealer and find out what a new/rebuilt pump will cost.

Your boss weighted the cost of new to the cost of rebuild/time lost on the jobs and opted to purchase a new unit. His need for a running piece of equipment is your gain. Good luck on getting it. TF