[grandville455]

I have a older craftsman air compressor and it has a leak at the bottom on the tank.. what can I do to repair the tank?

[Stuckinda60s]

Nothing, it's a pressure vessel. It's probably pitted from moisture.

[grandville455]

So U can't weld it up where its got the hole? if u make sure the tank can breathe while doing so?

[Simple Man]

It could be welded by someone who can do hi pressure welding. But if it has one weak area, there are probably others.

[grandville455]

So Just get a different tank then?

[Stuckinda60s]

You could get a new tank, if it wouldn't cost too much compared to the price of a new one. Craftsman isn't known for using robust pumps, they cut corners, so yours might not be worth replacing the tank.

I got a nice, made in USA, 2-stage,cast-iron, 80 gallon tank for $850. It'll do anything that's asked of it.

How big is your compressor? Would it support a larger tank? It might be time to get one if you decide to replace it, anyway.

[cuz68]

You might wont to try the JB weld that every one is talking about?

[gary bennett]

i had an old one that had a leak in the bottom. i drilled it to a size, tapped it, put in a screw with a faucet washer. that was 14 yrs ago & the guy i gave it to said it is still working. it topped off at 100lbs then turned off.

[Jim Scites]

If it's leaking on the bottom it probably rusted through from the inside out. They get water in them and it sits on the low spot inside the tank and causes rust. By the time you see the hole it's way too late. If you repair it and later it splits in the same place it can do a lot of damage when it lets go. I agree with at least replacing the tank. Whatever you do be careful.

[Johnnygoose]

Hose clamps, piece of heater hose, and #2 gasket sealer, been holding for over 5 years although my my compressor only puts out about 70 psi. See photo.

[Stuckinda60s]

You guys who are patching these tanks need to realize something. It's a dangerous practice. Take a 100 psi tank and calculate the amount of force on the area of the skin of the tank. It's scary! A 30" diameter by 40" tall tank at 125 psi has about 700,000 pounds of force exerted on its tank. And they can blow and throw pieces in all directions. Don't forget that those cannons used to throw pumpkins a mile are air-powered.

There's a real good reason why tanks have an ASME inspection plate on them. They're an inspected pressure vessel and when their integrity is compromised, they become dangerous. Any repairs to them should be done by a certified repair person.

[cuz68]

I have not been around many small ones, The larger ones that i have been around have pop off vales like a water heater but smaller.

[YVEYANT]

DeVilbiss makes all Sears/Craftsman compressors if that helps. Maybe call them and ask for a tank replacement. New compressors are pretty cheap these days. A lot of deals out there if you shop around.

[Stuckinda60s]

Okay, compressors have pop-off or relief valves. Why? The answer is to prevent the compressor from over pressurizing the tank, if it fails to shut off. Once again, why? To prevent explosions.

That's fine when the integrity of the tank is intact. That relief valve setting assumes that this is true. When the tank has been damaged, the relief valve setting probably exceeds the safe pressure and becomes meaningless. The tank is most likely to fracture when the compressor is running, due to the vibration and pressure pulses. This means it's most likely to explode when the air is being used and someone is in the vicinity.

Because of the dangers, tanks over a certain size are required to be inspected from the inside!

Look, you guys are free to do what you want. When someone asks advice I'm going to give them the best advice I can. I haven't always done the safest thing, but I'm not going to advise someone to ignore safety just because I got away with it.