Several compressor questions...

[DocsMachine]

Just finished my shop airline install and compressor relocation project.

Plumbed the main shop (2 car bays) and side machine room with eight drops all told, with a total of 11 QD connections, all run off a 60-gal CH upright. I moved it out of the main shop and into a side storage room, which made it a LOT quieter.

While I had the tank emptied to replumb the connections, I of course popped open the inspection cap and had a look inside. It was rustier than I'd hoped to see, of course, but from what I could see, it didn't look "dangerously" rusty. I also don't get like rust flakes and whatnot out with the drain water either.

I bought this thing in '98, so it's past 20 years old. Question one is, with relatively mild use (I don't paint cars and only use air tools sporadically, half the connections I put in are just for blowguns at the machine tools) and regular water draining (which I've always tried to do) what sort of life expectancy can a compressor like this have?

Should I start thinking about replacing it, or at least getting a new tank? Or just "monitor the situation" for another 5 to 15 years.

Question two is, along that note, does anyone know if Eastwood is planning an upright/60-gal version of that quiet scroll compressor? Kinda moot for me at the moment, as the move quieted it down substantially, but I'd be curious to know, anyway.

Question three, I've always been curious why somebody hasn't come up with a way to coat or seal the inside of a compressor tank, to prevent rust in the first place. Only good reason I can see- and it likely IS a good one- is that if the coating somehow cracks or chips, rust starts as a point, leading, I think, a lot quicker to a "point failure", rather than a more uniform, widespread coating.

Still seems odd somebody hasn't come up with something- an epoxy coat, or hot-galvanized, or something, to make an extra-long-life tank.

And going off that idea, question four is, has anyone given any thought to periodically treating or protecting the tank? Like emptying it, letting it dry completely inside, and coating the inside with something like Ospho? (Chemical rust converter.) How about Waxoyl?

Doc.

 

[thanasi]

I have had mine since 99 same one other then the noise level it hasnt skipped a beat. Im a tech, this is my personal air com for home i use it often with out any issues, only maint i have done is oil replacement and drain periodically. Never thought to look inside or even check belts to see their condition. Hmm might do that sooner then later, i do want to add a auto drain with a timer on it i have it just never got around to installing it. I get rust stains but i doubt it rusted to the point of worry/danger
Hahaha mine was a weeding gift to me from my wife lol

 

[EOC_Jason]

I've seen air tanks for 18-wheelers and whatnot where they spray the inside with some sort of coating.

What drain do you have on the bottom? Just the stock petcock like most have or does it have a ball-valve for easy access? See attached picture for an example of what I did on my dad's 60 gallon Craftsman. Makes draining MUCH easier, I would always drain out the water after use, but also the next day (if I remembered) I would drain it again as there would always be more water (Houston is very humid)...

Draining your tank regularly is 99% of what affects the tank's lifespan...

Considering there are tanks that are fine that people are using from the 60's & 70's... I wouldn't worry about it UNLESS you never drain your tank...

I bought a used horizontal that was from the 90's and took a look inside. Amazingly the sides were bare steel and no rust, but near the bottom you could see rust (but it wasn't bad, I flushed it all out good before mounting my compressor & tank on it). The old horizontal tank was from the 70's, so it lasted 40+ years before getting a pinhole leak, which actually was caused because the tank drain was on the side rather than bottom so there would always be some water in the bottom of the tank. Otherwise I'm sure it would still be perfectly fine today.

You can probably look up the model of that compressor and the manual might say the MTBF for the pump. As long as you check & change the oil even semi-regularly (again depends on usage), same with the air filter, and don't abuse it I'm sure it could easily last another 20, 30, 40+ years... All just depends on usage and maybe a little luck... Sometimes a screw will loosen on the reeds, or a bearing goes... but for the most part they are pretty solid. You will likely have the motor die before the pump.

EDIT - Added more pics of my Quincy... You can see the side-angle where the bung was on the side/bottom (I removed the drain valve so nobody could plug it in & build pressure). Interesting enough in the first pic you can see how the pipe from the pump goes to a 'canister' next to it, then to the tank. That canister is supposed to help trap moisture and it has a drain on the other side. It's very thick cast iron. I did not re-use it when I transferred my pump & motor to a new tank.

The 'new' tank like I said was from the 90's, but if you see the drain is on the bottom. It had a crummy petcock but I managed to pipe in a ball valve for easier draining. I was able to remove the big reducer on the bottom, and also on top, to inspect & flush the tank before assembly.

It's kind of funny, I bought the whole Sanborn compressor for $100, it had a 15A (3HP) motor, and the pump turned fine. It wasn't wired up right (the pressure switch was jacked) so I never got to test it. But I ended up selling the motor (after testing) and pump (untested) for more than what I paid so the tank was basically free. My little Quincy only has a 1.5HP motor but it runs sooo quiet, and like I said before it's a pressure lube (vs splash like most) and has the hydraulic unloaders on top so the valves stay open until oil pressure builds up.

 

[May Pop]

The canister is called a cushioning chamber to further quiet the compressor.