Crack in Air Compressor tank…

[StevSmar]

Ever since I purchased my air compressor it’s had a slow leak, but since it was either under a bench or in a corner I never looked to see what the cause was, naively assuming it was just one of the fittings needed re-sealing… until today…

It probably has only 100 to 200 hours of running spread over 20 years, with the air tank drained after each use.




The crack is maybe 1.5” long… gulp… 3 gallons at 120 PSI is a lot of energy…

Should I:
1) Buy a new compressor.
2) Buy a new compressor and a lottery ticket.
3) Try to find a replacement tank.
4) See if I can get it repaired.

 

[boilerhouse]

Any of the three options that do not involve trying to repair the tank. Not worth it if done professionally (and properly), and not safe if it isn't done professionally.

 

[DavidR8]

Buy a new compressor with an ASME certified tank.
Do not mess around with getting it repaired.

 

[Tom O]

Use the tank for blast forge or a melting furnace for casting metal.

 

[slow-poke]

While were on this topic how often do you guys drain your air compressor?

I hope I don't have an accident waiting to happen. My compressor must be more than 20 YO.

 

[Former Member]

The is the most common failure on horizontal tanks and when they fail its with explosive result.

Run away and buy new.

 

[boilerhouse]

My tank is probably 20 years old too. Should probably drain it everyday I use it, but probably drain a couple times a month, but also gauge roughly how much water comes out. Usually it's just a few tablespoons. You can get auto devices on the drains and set them on timers if you get a lot of moisture and don't have a good "manual" routine.

 

[DavidR8]

I drain mine with every use.
I have drain extensions so that they are easy to reach.

 

[Proxule]

I would chase that crack with a die grinder and fill it up with weld. Then hydro test it, or do your own ?
Safer route is likely a new tank.....

gluck either way!

 

[Aliva]

looks like a fatigue crack possibly from vibration. If you feel confident, gouge and weld then hydro test. Personally I'd scrap it. I wouldn't take the chance. If it's cracked once it may just crack again in some other place.

 

[Susquatch]

IMHO, Nothing to discuss really.

Time and excuse for a nice new upgrade. Any SWMBO worth keeping will agree to that.

Turn the old unit into something else or scrap it. Don't Fk with it.

Be grateful that you and your shop are still in one piece.

 

[Susquatch]

While were on this topic how often do you guys drain your air compressor?

I hope I don't have an accident waiting to happen. My compressor must be more than 20 YO.

I love this question and would like to know best practices too.

I have 2 compressors, a big one I hardly ever use and a little one that gets used several times a week.

 

[Proxule]

looks like a fatigue crack possibly from vibration.

This is likely the cause.

 

[StevSmar]

3 gallons at 120 PSI is a lot of energy…

Correction 20 gallons…

Thanks for confirming my suspicion- buy a new replacement tank, or a new compressor.

But this has got me thinking, do I even need an air compressor?
I’m not routinely spray painting or sandblasting (yet…). The six air tools I have are available in electric versions and I have three of those already. A source of air would be nice to blow chips around the workshop where I can’t easily clean them up though.

Buy a new compressor with an ASME certified tank.

This was a Quincy air compressor which came with an ASME tank. Thanks for pointing ASME certified out though, that’s a desirable feature to remember to get.

looks like a fatigue crack possibly from vibration

My suspicion, is that it was dropped when it was being delivered- hence it always having a leak (that I should have chased down…), but the leak had gotten substantially worse from the crack propagating.

 

[whydontu]

My seriously weird-ass use for an old compressor tank. I wanted on-demand cutting fluids on my mill and lathe, but every coolant pump I found was way too big for a bench mill and a 10x18 lathe. Flood coolant is just too messy. So I mounted the old air tank on a shelf up against the ceiling of my shop, ran plastic hoses from the tank to my machines, and put a small bilge pump in a bucket under my work bench. Bilge pump output runs up to the tank. Ran hoses from the chip trays to the bucket. A couple of mag bases with small needle valves connected to fine nozzles aimed at the cutting edges or workpieces. Needle valves adjust from one drip every few seconds to a steady stream.

Gravity feeds the nozzles, when the bucket fills I turn on the bulge pump and refill the tank. Rube Goldberg at his finest.

 

[CWret]

Agree with @Susquatch and others - time for an easy to explain need (not a want) for a new one. Who can argue with safety. Not sure what a SWMBO is but i think most of us are happy to have one.
I repaired (welded) an old air pig with a small leak. I remotely powered it up to 150psi and then used it at 100 psi max. Then i got smart and got rid of it. Was going to give it away and then quickly decided that was a worse choice than using it myself. Sometimes we do things at home that we would never do at work. Silly.
I sold my 15+ year old 4cfm/10gallon compressor because it was so loud- it still looked and worked well so i got a fair price. I think a reasonable life expectancy for a compressor (that only gets drained occasionally) is 20 years.
My new one (2years ago) is similar size (CT’s Maximum, WhisperTech, 4cfm/15gallon tank) but ooooooh so much quieter. I also have a very nice little King Canada FlexAir ultra-quiet (2.4cfm/4.6gallon). Nice thing about the King C is it has aluminum tanks. I use the little one most of the time but run them in tandem to supply the plasma cutter. Thanks to this post - today i installed a hose to extend the drain plug (for the WisperTech). Super simple to drain now plus I have a short blow hose right at the compressor.

I’ve owned a lot of large and high pressure compressors. I’m a pretty good welder - but repairing that air pig was one of the dumbest things I’ve done.

Side story: on a construction site an excavator (general contractor’s sub) hit our rock drill pretty hard. It dented the 50 gallon air tank and also bent the drill tower at the same time. It was an insurance claim. We asked if they wanted a price to repair and re-certify the tank instead of replacing it. Repair would be rather quick but replace was a delay with job schedule impacts. They answered immediately and emphatically NO. Cut it apart and scrap it!

 

[Janger]

yah cut it up so no one else is tempted. or put a sledge hammer into it.

 

[StevSmar]

Yes, I’ll put a hole in the tank so that it can’t get used for a pressure application by anyone.

I’ve sent and email to Quincy’s Winnipeg’s representative to see if parts for a 22 year old design are available.

 

[Ironman]

Yes, I’ll put a hole in the tank so that it can’t get used for a pressure application by anyone.

I’ve sent and email to Quincy’s Winnipeg’s representative to see if parts for a 22 year old design are available.

I drain my tank every 20 minutes for 20 seconds, as I have an electronic drain valve.
My Quincy 325 is made in 1934 and they have parts for it. Cranks, piston rings, valves, etc. but gaskets are getting hard to get.
So far you are lucky.
A good high strength air tank can be had from a propane tank. I made mine from a 100 gallon school bus tank and hydro tested it at 600 psi for 24 hrs. It's been in service since 2009.

 

[Dan Dubeau]

Congrats on the new shell for your foundry!