Best fix for rust hole in air tank?

[Buzzer John]

My air compressor tank has developed a small rust hole and I am looking for the easiest fix that does not call for a new tank. I only use this thing for filling tires. I have thought of screwing in a sheet metal screw with a bit of a gasket. I might be able to weld it, but I would probably just burn a larger hole. Any other suggestions?
Thanks, John

[pressurerelief]

Buzzer John, I would not repair but would replace. I know you said you did not want to do this but this is the only safe alternative. You probably have many other rust pockets waiting to break through. You have a potential failure of a pressure vessel on the horizon. Stay Safe.

P/R

[Arcane]

If you don't want to buy a new tank, buy a used tank that is in good condition. That basically means it would pass a hydrostatic test. Rust holes are like rats, if you see one, there's many more that you don't see. Sometimes airtanks fail catastrophically like a bomb and sometimes they just leak and it's pretty well impossible to tell in advance which one it will be. There's been a few instances where a great deal of damage was done when one blew up and if you were right there when it went, you would stand a good chance of getting hurt very badly if not killed. That also applies to any innocent people nearby. It really isn't a good idea at all to try to fix a problem tank that probably has already paid for itself many times over.

[Buzzer John]

Thanks for the comments about safety. Would an old propane tank be strong enough? I have see some made into a portable air tank, but I don't know how much pressure they hold. My unit cuts out around 100psi.
Again thanks, John

[Roy Andrews]

i welded the tank on one of my compressors that developed a small pinhole leak from rust about 15 years ago. if your worried about your welding just clean it real well and braze it. rust holes or welding them closed will not cause any sort of catastrophic failure. rusting weld joints actually make a tank less likely to fail dramatically due to over pressurization as the weak seams open up fairly easily and relieve the pressure. i dont offer this as hearsay or old tales. i once worked for a company that made tanks and i was involved with the testing and failure analasys of a lot of tanks. we had fixtures that blew up tanks and we did it every day. it was incredible the damage a small 20 gal .125 wall tank would do.

[Evan]

A 20 lb propane tank will work fine. They are rated to at least 300 psi. Take proper precations to avoid igniting residual propane. Washing with solvent and then hot soapy water followed by a rinse of boiling hot clean water will work.

Disclaimer: Some may say it is dangerous. It is but only because any vessel filled with compressed air is dangerous. Small propane tanks and small air tanks have the same steel and same construction as well as same burst pressure requirements. Actually, propane tanks are somewhat better regulated. YMMV.

[Buzzer John]

Sounds like the propane tank is my best bet. I can probably pick one up at the local gas supplier. He used to have a pile of them with the old style valve.
John

[websterz]

Thanks for the comments about safety. Would an old propane tank be strong enough? I have see some made into a portable air tank, but I don't know how much pressure they hold. My unit cuts out around 100psi.
Again thanks, John

Look at the collar that surrounds the valve. There SHOULD be a DOT rating stamped there, something like DOT-250. The number is the tanks safety rating in PSI. Give yourself a comfortable safety margin, say 75-100psi above what your compressor is capable of putting out and you should be fine.

[wierdscience]

An old post on the subject.

http://bbs.homeshopmachinist.net/sho...OMPRESSOR+TANK

[kendall]

I'm normally very willing to go with 'fixes' but for some reason I feel that the only real fix for an air tank is replacement.

I had a fantastic little compressor for work (carpenter, for nail guns etc) that I really loved because it was light, and extremely quiet ( a HUGE plus when you have to listen to it all day long!) I bought it used, and had it for over 15 years, and repaired several leaks towards the end of it's life with welds,braze, and even epoxy only to have a new leak show up a short while later. When I finally stripped it down, thee were 8 repairs along the bottom. (stupid, but when I find something I like, I try to keep it going as long as I can!)
I finally tossed the tank, because while prepping for another repair, I noticed several divots forming where I was sanding, and saw that I could easily press a needle through them.

You can't tell what the inside is like without a serious inspection, and if it was rusted enough to leak in one place, there are several others that are very close.

Find another tank, there are hundreds of tanks tossed all the time because the motor or compressor died, save the headache, replace the tank.

A propane, freon, or even another air tank is great. A few years ago I trashed an old water heater, and noticed a tag on the tank itself that stated 'not to exceed 300psi" Which is about what a lot of air tanks are rated for.

Ken.