Compressor head and motor

MountainD

Technical Excellence Contributor
my 20 year old 60 gal porter cable compressor is tired and running very hot. It’s on its way out and although rebuilding is a possibility, I’m thinking of upgrading the unit, keeping the tank, and building a new motor/compressor assembly for the top. Leading the top of my list, being relatively frugal, would be the HF 5HP twin: https://www.harborfreight.com/145-psi-5-hp-twin-cylinder-air-compressor-pump-67698.html
but I bet there are better options to consider. the quiet California Air Tools compressors are interesting but I’m sure someone here has a great idea. I’m currently plugged into a 50A 220v 1 phase, so power isn’t really an issue.
 

erover82

Well-known member
I like having multiple tanks, including a detachable small aluminum one. Small job inside? Close valve to big tank and start it up. It'll fill up fast and save your ears. Small job outside? Disconnect small tank and carry it outside.

Another thing I like doing is plumbing in an aftercooler which cools hot compressed air and causes moisture to condense out. This extends the life of your tools and is critical for painting. Many high end compressors include them, so if you're browsing turnkey solutions, that's a feature I'd look for. Example: https://www.aircompressorsdirect.com/EMAX-ES10V080V1-Air-Compressor/p18822.html
 
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UnfrozenCaveman

Well-known member
I like having multiple tanks, including a detachable small aluminum one. Small job inside? Close valve to big tank and start it up. It'll fill up fast and save your ears. Small job outside? Disconnect small tank and carry it outside.

Another thing I like doing is plumbing in an aftercooler which cools hot compressed air and causes moisture to condense out. This extends the life of your tools and is critical for painting. Many high end compressors include them, so if you're browsing turnkey solutions, that's a feature I'd look for. Example: https://www.aircompressorsdirect.com/EMAX-ES10V080V1-Air-Compressor/p18822.html
...genius... !!! I've just been running long hoses through the house for trim work, etc. :rolleyes:
 

mitherial

Well-known member
If portability is high on your priority list and your portable CFM needs are modest, you may want to consider something like Milwaukee's M18 battery portable compressor--currently $100 off [or the Dewalt equivalent]:

2.0 gallon tank, 1.2 CFM@90 psi. It's certainly not the most powerful option, but is extremely portable, and the M18 platform is great.
 

MountainD

Technical Excellence Contributor
great suggestions, but outside my $$$. just looking for best refresh for the $$.

most my big stuff is sandblasting although sprinkler blow outs is definitely On my list. But sandblasting is the big hog. 12-15cfm @90/100psi is ballpark. I am wanting to get A nice TIG if I was gonna toss down wife-attention-getting funds…
 

mitherial

Well-known member
Changing the motor is certainly the lowest cost fix, but just be sure that your tank is not completely rusted out (a real possibility after 20 years), or you may have to get a new tank anyway.

I doubt anything portable will be up to task with sandblasting (even the ARB twin is only rated for 6 CFM). I have a big 20 gallon Craftsman, but I never use it or my air tools now that I've changed over to Milwaukee M12/M18; the smaller Milwaukee M18 inflator does a great job with airing up reasonably sized tires (just input what press you want, and take a break). I'm tempted to sell the big compressor when I next move, but I am sure that if I did, I'd find some high PSI task.
 

erover82

Well-known member
great suggestions, but outside my $$$. just looking for best refresh for the $$.

most my big stuff is sandblasting although sprinkler blow outs is definitely On my list. But sandblasting is the big hog. 12-15cfm @90/100psi is ballpark. I am wanting to get A nice TIG if I was gonna toss down wife-attention-getting funds…

Do you have a motor to drive the pump head? HP rating? If you're looking for something a bit better than that HF unit, you could look at two-stage heads, but it depends on your motor. Media blasting benefits from cool dry air too. You can build an inexpensive aftercooler from a transmission cooler and AC fan, then put your oil/water separator right after it.
 

MountainD

Technical Excellence Contributor
It is a 3.7HP (running) motor. Since I am not doing any ultra high PSI work, I was thinking of staying single stage. My rationale is that the 2-stages are great for high pressure, but I am not needing a 175PSI system---plus you only have it "in storage" until it is depleted and then you are at the mercy of a vastly reduced CFM rating. A 5HP Dual stage puts out fewer CFM than a single stage--mainly because it is wanting to do it to a higher PSI. But "keeping up" cfm, it produces less for a given system. I am NOT a pump expert, so if there are added benefits that outweigh this, I truly am all ears!

As for cool air, my system is running the air through about 40' of black pipe (some folks use copper) that runs across the ceiling and then down the wall into a drain fitting with the air take off fitting about 1' up that then runs through a water separator above that. I painted (HVLP) my 90 with this set up and it worked out just fine both on temperature and H20, but all good advices. My sandblaster doesn't mind my set up, just minds the CFM rating at times... So most likely will continue with single stage but am not theoretically opposed to a dual stage. Does it keep air cooler/dryer?

I know I can get a 2 cylinder or 3 Puma pump, a 5HP (running, not peak) motor and keep it under $1K. That is what I was thinking. I will check my tank, but last I checked I am good. I regularly de-water my tank, so I am ahead of the game of some that way (been meaning to put the auto-discharge port on it...). I have a hose permanently attached and I open my ball valve and drain right into a bucket often enough. Rust happens, but so far so good. I put two alkaseltzers in the tank every 6 months to convert all the rust to a rock hard coating.

I am kidding about the alkaseltzers. However, now that I said that out loud....It wouldn't be bad idea to slosh a rust converter through it from time to time!
 

erover82

Well-known member
It is a 3.7HP (running) motor. Since I am not doing any ultra high PSI work, I was thinking of staying single stage. My rationale is that the 2-stages are great for high pressure, but I am not needing a 175PSI system---plus you only have it "in storage" until it is depleted and then you are at the mercy of a vastly reduced CFM rating. A 5HP Dual stage puts out fewer CFM than a single stage--mainly because it is wanting to do it to a higher PSI. But "keeping up" cfm, it produces less for a given system. I am NOT a pump expert, so if there are added benefits that outweigh this, I truly am all ears!

As for cool air, my system is running the air through about 40' of black pipe (some folks use copper) that runs across the ceiling and then down the wall into a drain fitting with the air take off fitting about 1' up that then runs through a water separator above that. I painted (HVLP) my 90 with this set up and it worked out just fine both on temperature and H20, but all good advices. My sandblaster doesn't mind my set up, just minds the CFM rating at times... So most likely will continue with single stage but am not theoretically opposed to a dual stage. Does it keep air cooler/dryer?

I know I can get a 2 cylinder or 3 Puma pump, a 5HP (running, not peak) motor and keep it under $1K. That is what I was thinking. I will check my tank, but last I checked I am good. I regularly de-water my tank, so I am ahead of the game of some that way (been meaning to put the auto-discharge port on it...). I have a hose permanently attached and I open my ball valve and drain right into a bucket often enough. Rust happens, but so far so good. I put two alkaseltzers in the tank every 6 months to convert all the rust to a rock hard coating.

I am kidding about the alkaseltzers. However, now that I said that out loud....It wouldn't be bad idea to slosh a rust converter through it from time to time!

Two-stage are generally for high power work, longevity, and efficiency - a necessity in large industry, but only a luxury in a shop. I'd stick with a single-stage.

That long pipe run should do it for your uses. Sounds like a good general setup.
 

erover82

Well-known member
Changing the motor is certainly the lowest cost fix, but just be sure that your tank is not completely rusted out (a real possibility after 20 years), or you may have to get a new tank anyway.

Metal and rust fatigue is real. Tanks may be built to last as few as 500 full pressurization cycles.

 
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