Technical There was a thread awhile back discussing air compressors.

In that thread someone mentioned a place/company -maybe in Michigan? I can’t recall, but US made cast iron compressors.
I went to HF for one today, but the paperwork in the compressor didn’t mention whether it needed to be spun at 1750 RPM or 3500 RPMs. My motor is a 3 HP 1725 RPM.
I figure a company that makes them, rather than a store that sells them, can send me what I need.
Anyone recall the thread or have a line/lead on who to contact?

 

Eaton corp. sells a nice line of pumps. Good customer service.
I like the low rpm compressors. They are quieter and create less heat.
Bought a pump from them and the guy in sales was very helpful. My motor spins at 1740 rpm. Since the pumps all come with a pulley of a certain diameter, he was able to recommend the proper diameter of the drive pulley on the motor. Reason being is that the pump wants to spin at a certain rpm for proper splash lubrication within the pump.
Makes perfect sense.

 

Well, today I went a bit Kamikaze on my compressor. Back when I built it, it was an old pump my dad had under his work bench. Probably as old as I was (and am) at the time.
I used a 60 gallon ASME certified tank, a 3 HP motor, etc.

Geesh, it took 25 minutes to reach a 100 PSI. So that’s where I set the cut off at.
But, like Tim Allen I needed “more power”. So kept raising the cutoff point, trying again, easing it, mercy. 2.5 hours to get 8 lug nuts off my tractor.
I started with a 1/2 inch impact, and the 3/4 wouldn’t budge them until I got the pressure up to 135 or so.
Ya, I need a new head for the beast.
Thanks for the tip on Eaton.

 

You sure your not spinning it too slow ? If the head is that old it's probably made to spin 3500 rpm. If your using the 1740 rpm your spinning it almost half of its rated speed and doubling the time to compress air..

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What gets me is it seems like all the new compressors like Ingersol, Husky etc. all shut off at 175 psi. Why? All of them are driven at 3500 rpm. Loud and obnoxious. Seems like they will gladly cruise right up to the 125 psi point and then struggle to make that extra 50 psi. At this point is when the pump is working harder, causing excessive heat buildup which creates moisture in the system. If I had one of these, I'd replace the pressure switch with one that cuts out at 125.

 

It’s spinning correctly. I asked a place that used to sell parts back in the day, bought a motor pulley from them. And the pump was spinning at 750 RPMs. I took the pump in with me, they sold me a pulley for the motor.

 

Most (if not all) pressure switches are adjustable. Some are set for a differential between cut in/out and you just adjust one nut and it raises the cut in/out. Others you can adjust the pressure differential and the cut in/out pressure.
Then there’s the fancy digital one you can pay up for. lol.

 

@1ton it's to give you more working time before the compressor kicks again. With 175 PSI your pumping/forcing more air into that 80 gallon tank than you would be at 125 PSI.

Whether this is a plus or minus is a mystery to me. I understand longer work time but does the extra time the compressor runs to go from 125 to 175 equal out to were it really doesn't matter? Only the universe knows....


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Quincy makes some of the best compressors on the market, At least the old ones were.

 

The extra pressure is sometimes needed for air tools. Way back when, my dad’s compressor was set at 190 off, 160 on. But this was the 70’s into the ‘80’s. Then I started picking up IR impact tools, we found out we could lower the on/off. I think we settled on 135/100 or so.
This was used (among other things) to mount the wheels on his tractors (bottom dumps and transfer).

But as air tools have become more efficient, I can’t see a need for 175 (in my use)

 

All air tools have a sticker that states 90 PSI max and have been that way as long as I can remember. So again it comes back to available volume vs real tool working pressure.

175 PSI 10 gallon tank will feed that 90 max PSI tool longer than a 125 PSI 10 gallon tank.

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Be sure your tank has the capability to handle the high pressure. The max working pressure will be on a panel attached to the tank. Exploding tanks are no fun.

 

I watched a video on youtube where a guy built a liquid cooled coil in a 5 gallon bucket for his compressor to manage heat and the difference in air temps coming out of the compressor and the temps after the bucket were substantial. around 150 degrees different.

 

I built an expansion setup on to my compressor, it dropped temp at tank inlet about 120 to 125 degrees and pretty much cured all my moisture problems. Living in Kansas the humidity can get really high and really hot around here.

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Interesting stuff.

 

Sure. But how much torque could you get from say an impact wrench from IR in 1972 vs one made in 2022?
Same 90 PSI, but at least twice the power.
That’s my basis of what I had mentioned.
Heck, even cordless impacts made today out perform what an air impact did 30-40 years ago.

 

My Puma compressor has been running 37 years. It's hardwired to the panel and has never been turned off. They sell pumps too. http://www.pumaairusa.com/products-16.html . 810-830 RPM . Mike

 

As with @BJR , my old Quincy 325 has never let me down.

 

I'm half Scots i.e. thrifty, and put together a small compressor system using 2 HF ultra quiet 2hp compressors and a HF 7 gallon alloy portable tire fill tank. The 2 compressors also have alloy tanks. It runs my half inch impact wrench just fine. I don't paint, so no idea if it could support that. And I can stand next to it and talk to someone while it's running without raising my voice. I must have deleted the picture of it, so I'll get one later after NASCAR is over and post it.

Just remember, the tanks are bombs when full. If they are corroded because you've never drained the water out, the max pressure before failure is greatly reduced. My system having alloy tanks is less susceptible to corrosion, but aluminum has no fatigue limit, and is also a potential bomb. I hardly use it, so for me, I'm okay with that.


It was still on the camera! And notice that the large tank is up top, and the plumbing to it can drain to the lower compressor. Not perfect, but I haven't seen water in the large tank the few times I've drained it.

 

I haven’t used this compressor much since built. My dad had a large one on the front shop, and I drug my oil-less, noisy Craftsman over, used it mainly-it’s a water maker for sure.
I built this compressor for use in the back shop for the blasting cabinet.
Man that was a long time ago. But anyways, at 100 PSI it didn’t keep up with the cabinet. I didn’t realize at the time it was because the nozzle was worn out when I got it. Who’d have thunk a used cabinet would have a worn out nozzle?
So it has pretty much sat for 25-30 years. I aired up a tractor tire once with it, and this weekend was probably the 3rd, maybe 4th use of it.
The tank was as dry as possible when I got it. It was a vacuum tank first. Dayton as I recall, pretty confident it had no moisture in it from its previous use.

 

I think I commented on an air compressor post sometime a go. We purchasaed a Castaire in 2016 and it just keeps chugging along. It is manufactured in Minnesota but that's close to Michigan
https://castair.net/about-castair/
We also purchased a free standing air cooler
https://castair.net/air-drying-equipment/air-cooled-aftercoolers/

 

I think it was your post!!!
Thanks, going to save the info this time

 

If you plan to use it for a sand blaster, you need to not only worry about pressure but air volume. I also think you should get a bigger compressor.....tank and all. My sandblaster operates off an Ingersol Rand that has the 3650 RPMs. Not my first choice but I got a deal on it brand new from a guy who worked at the factory. It runs a lot when I'm using the blaster. I put it in a corner and cut a hole in the wall so it could pull air from outside the building with its pulley/fan. I also put an air intake that ran thru the wall and has an air filter on it outside. Then mounted a fan near it to blow more air on the pump while it runs.


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I bought some of these as they are WAY cheaper than Miltons. This should be enough to do a compressor to sandblaster and some spares. Best to convert all air tools though....as they won't fit the other chucks and fittings you already have.

Here is the difference using Milton pictures.




Milton wants more for one air chuck with no fittings than the WYNNsky wants for this group.

 

Dave, why don't you put a T on the bottom compressor instead of the L fitting? Then run a drain line down with a valve instead of letting the water run back to the tank.

 

In my shop, I have an IR 2.5 hp compressor with a 20-gallon tank that puts out 4.6 cfm. It works for some of the stuff I do but when I need more volume, I have a Honda powered 5.5 hp wheelbarrow IR with an 8-gallon tank that kicks out 11.8 CFM continuously at 90 PSI. Max pressure on that one is 135 PSI. I added a half inch fitting to the manifold so that I would have plenty of air to work with. I can run an arc gouge or air grinder all day long with the wheelbarrow unit. I'm not doing any commercial work anymore, so I've thought seriously about putting an electric motor on the wheelbarrow unit and piping into a larger tank through condenser coils.

 

Lazy! What can I say...

You're right on that. I ran out of fittings when I put it together. And I can't use the excuse that I haven't been to the hardware store since. In fact I have become an Ace Hardware premier customer... yeah, I know, but again what can I say? SWMBO thinks I own a piece of the store.

I also like the water cooled line section above. I should talk to one of the guys I used to work with at the lab, and ask him to make a coil out of 3/8 stainless steel tubing. He and I built a custom emissions analytical bench almost 20 years ago, and it had a coil just like that to reduce the amount of water getting to the vapor separator. They don't like much above 45-50 % moisture in the gas stream. This made them last longer before requiring maintenance.

Think I'll give him a call tomorrow...

 

Good info as always. I believe I have enough tank (60 gallon) just need a proper compressor pump. It did serve the purpose yesterday though, but took quite a while to get from 100 to about 120, longer from 120 to around 135. But ran the 3/4 impact for what I needed to get done.
I do have some cabinet blasting to do in the near future, so definitely will be looking at a different compressor pump and run the best I can find for the 3HP motor I have.

If I have to take a beer break every 10/15 mutes to let it fill and cool down, I’m okay with that

 

Mmm! Beer! And donuts!

 

The breakfast of champions

 

I only drink on days off after 10 am, so “brunch” for me