Hot Rods Question about air compressors

My ancient air compressor may have given up the ghost. It's an ancient Curtis that was manufactured in the the early 50's . It has been a great compressor and has handled my needs perfectly. The motor died and I am getting estimates from rebuilders any where from, it can't be rebuilt because of age to $600 to a $1,000.00. Don't know if I want to invest that kind of money into this old pump and tank.

If I have to buy a new compressor what kind of CFM should I be looking at to operate my small sand blast cabinet and pressure tank blaster. My current compressor could handle it but I had a lot of catch up time between uses. I am not a commercial shop. Just a hobbyist working out of his home.

Northern tool has a Quincy that is rated at around 13 14 CFM that fits my foot print without to much h***le.

Any suggestions are appreciated.

 

If the electric motor died, why not just replace that? A 5hp compressor duty motor can be had for about $200....

 

A new motor and a rebuild is easy
There is a reason it lasted so long.

Quincey builds a great compressor

My Big Red is 20. Runs great. 24cfm handles 2 guys working and runs my blast cabinet well.

Champion makes a good one as well

We have an IR at school. Great but loud. The other brands usually operate at a lower rpm

 

hard to make recommendations without knowing what your old compressor is, and what your needs are...

a pressure blaster's air requirements mostly depend on the nozzle size. For example, my 2 stage 5 hp compressor (from the 1970s). handles my pressure blaster fine if I use a 1/8" nozzle, and replace it when it gets worn a bit.

 

I just bought a 5 HP 2-stage compressor from Harbor Freight. Price was $749 with a "super coupon" ($799 regular price). There's a 3 cylinder 5 HP compressor they list, but I don't think it's 2-stage.

I hooked up the electric to mine this AM and did some bead blasting. I don't know what diameter nozzle I might have, but it's the same one I've used for years so I would expect it's somewhat enlarged. I bead-blasted some parts for at least 5 minutes steady and the blaster was working great. Compressor ran constantly while I was blasting. I had set a pressure regulator to 120 PSI to the hose, and had set it with a blow-gun "blowing" .When I stopped bead blasting I immediately walked the 20' to the compressor which was maintaining 120 PSI in the tank.

I had a Ingersol-Rand 2 HP compressor which was working as it should, but I was blasting 20 seconds....waiting a minute....blasting.....waiting ..... and on and on.

FWIW, I could only get to 1 of the two wiring "legs" in my electrical box, but the compressor was pulling 15 Amps on that leg of the 240 V power. I only have 60-100 AMP to my shop and the lights did dim for a moment when the compressor kicks in, but it didn't blow the 40 Amp fuses on it's circuits. Granted, I won't be able to weld and run the compressor at the same time, but then I'm not coordinated enough to bead blast and weld at the same time either.

Lynn

BTW....If you're interested PM me with your e-mail address and I'll forward the e-mail from Harbor Freight with the super coupon. I guess it'll be good at all stores?

 

You must be thinking of a 3600rpm motor?

Reason I ask, I'm looking for another 5hp 1725rpm motor, hard to find an old used one in a pile for 200.

 

Ok, a few bucks more..... https://www.walkerindustrial.com/L3...MI5OWk1bfu3QIVHrjACh0R-QUzEAQYAyABEgK8EPD_BwE

 

Old compressor tanks can be dangerous.

 

I bought this 5 hp 1725 rpm 184T frame Baldor Motor for my compressor a few months ago.
eBay item number:
183467117194
Those guys had it here a lot quicker than I thought it would get here.
Checking a it that L3504 Baldor That Crazy Steve showed is 1/2 hp and not 5 hp it is a rather small motor with a 56 frame and 7/8 shaft.
The L1430T, 5HP, 230V, 60HZ, SINGLE PHASE, 20.6AMPS, 1725 RPM, 184T FRAME, OPEN ENCLOSURE, RIDGED BASE, SHAFT DIAMETER 1.125", SHAFT LENGTH 2.75" is the one I showed that I have.

 

FWIW, Tractor Supply is running a clearance sale on Porter-Cable compressors. Last week I bought the 30 gallon upright (which is EXACTLY the same as the $449 Dewalt 30 gallon unit) for $349 which is less than Harbor Freight's ($354) 29 gallon unit.

 

Isn't that a .5 hp, or half a horsepower? Not 5 full horsepower.

 

Northern tool has a Quincy that is rated at around 13 14 CFM that fits my foot print without to much h***le.

Any suggestions are appreciated.[/QUOTE]

I would buy the Quincy I have, it's a model 325 I think it's 18 CFM and runs at 1750 rpm's and is pressure lubricated not splash. I bought it brand new 33 years ago and never regretted spending the money. There are a lot of things to consider when buying a compressor, CFM, RPM, pressure or splash oiling, noise, quality and cost. I put cost last because a good compressor lasts a long time The cheaper HF, Tractor supply, Lowes, etc. turn at much higher rpms to have the CFM and pressure ratings, they are also very loud. I can stand next to mine when it's running and still talk on the phone.

Good Luck and choose wisely.

Pat

 

Buy the biggest compressor that will fit your space and pocketbook. Stay away from oilless compressors. Compressors made in the USA are better.


Bones

 

Good point about the noise. The HF 5 HP compressor I just bought is louder than I wish it was. But, I have it now and I'll probably just wear earplugs when I'm using a lot of air.

Lynn

 

wow! That one's not even THAT old.

 

New compressors are not built anywhere near what the "old" one's were, I would find a motor

 

https://www.zoro.com/weg-air-compr-mtr-5-hp-1745rpm-208-230v-184t-00518os1ccdol184t/i/G4267216/

$447

https://www.ebay.com/p/Baldor-Air-Compressor-Electric-Motor/2035155984?iid=183469871572

$339 for a Baldor

 

Not to hijack this thread but seeing that tank all exploded like that I have to ask,
Is there any way to tell the condition of an old tank so as to avoid such a problem?

 

From what I've been told by folks who should know, there is a test that can be performed, and is required by OSHA on shops that require OSHA inspection, that will certify an old tank that is past a certain age.
Have no idea what it is called, or what is involved, nor the cost. My shop isn't under OSHA as it is only a hobby shop used by myself and my son. I do have some concern about this, as my 2 tanks, 1 an 80 gal. and 1 60 gal probably date back at least to the early 50s, maybe older
Accordingly I have them in a shed outside a concrete block and brick veneer wall from the shop and have the pressure switch set for on @ 85psi and off @ 120.

 

Okay, so what pressure was the exploded tank subjected to before it blew up? How old is it?

Without more information, one can't blame a tank explosion on the age of the tank.

 

Mine is a 80 gallon Craftsman that I bought 12 years ago. The motor finally up and died last year. I took it into a local shop, they cut the feet off and welded them to a new 5 HP motor, I re-installed and it works great.

My compressor is mounted in an outdoor closet behind my garage where it stays a bit cooler and I don't have to listen to it! When the old motor shorted out it also blew that regulator box on the front but I found a new one on line. This has been a real work horse and I have been quite pleased.

Next time I am buying a slower RPM compressor, this thing runs too fast and makes too much noise.

Craftsman is not the same company anymore, this was USA built, they aint anymore.

 

More often than not tank failures of the type pictured are due to the fact that the shut off valve failed and the compressor continued to run unnoticed and way over pressured the tank. It is far more likely for a tank to develop pinholes with age than have a catastrophic failure as shown in the picture.

 

That's why I also have a pop off valve set just above point where switch shuts off compressor.

 

As dirty old man said, there are inspectors With OSHA and other safety organizations that inspect them and certify them. When I was teaching auto mechanics one inspected the 80 gallon tank on our compressor and found a crack. I ordered a new tank from Grainger and the old one got cut in two to make a water trough for a local farmer. Once we got it out where we could see it the crack was pretty noticeable.

I'd agree with the tanks getting rust pits inside, too many guys never drain the water from the tanks until they have issues from water in the lines. I argued to no end with the dairy farmer I worked with that he needed to blow the tanks at least once a day and after each shift would be better. He thought it took too much time but quite often lost valuable time during the shift because water took it's tole on the air cylinders in the milking barn.
When I worked at Frank Weaver Pontiac in Waco in the 70's you knew it was quitting time when you heard the service writer open the valve to drain the tank after shutting the compressor off. We never had air tool problems in that shop.
It should go without saying that every compressor no matter what the size should have a good working pop off valve on it.

 

Pop off valve

I also installed an electric valve on the bottom of the tank that is programmed to release air/water ever hour on the hour, 24-7. Easier than trying to remember to empty daily.

 

[QUOTE="Bandit Billy,
I also installed an electric valve on the bottom of the tank that is programmed to release air/water ever hour on the hour, 24-7. Easier than trying to remember to empty daily.[/QUOTE]
I wish I had had one of those on the compressor we had in the school shop. And the two side by side tanks on the dairy. I may have to get one for the one I have now.

 

I recently bought this monster, it has 4 pop 0ffs.

 

That is a beast.

 

If you can afford it , get a screw type .

 

I'd like to second and third/fourth the recommendations for as large as you can reasonably afford, one that is oiled, and Quincy compressors are very nice. I've been happy with mine for years.

Good luck.