Welding Air Tank

[gus]

My '54 PD4104 wet tank has four holes, the largest is about 3/16". I punched all over the tank and found no more weak points or any weak metal adjoining these holes.

Has anyone welded an air tank this old and been successful?

I have the tank out so welding is no more work. I found that it was bypassed because of one pinhole. I made the other holes with a punch and hammer.

[Hartley]

You could probably plate over the holes with a wide patch, But I would guess that if pinholes are coming from inside
your best bet may be to replace the tank if possible. I tried that on one and the heat from welding broke a bunch of
garbage loose inside the tank which clogged up all the air fittings. Then I had more holes appear within a short time.

If it's a critical tank like brakes or the wet tank I would rather suggest replacing it than trying to patch. Safety is Everything
and as you probably know, No-air No-brakes.

Hope that helps a little....

[gus]

Dr,

I wouldn't even be thinking about welding  if I thought I could find another good one. Since it is such an odd setup I'm afraid I won't be able to find one.

It is pretty hard to plate because it is on the curved end.

My thought is to fill the hole with a bolt or screw and weld around the head. If the metal around the hole is too weak to hold the weld then it is definitely new tank time.

Brazing might work even better.

Junk inside from the welding isn't a problem because the drain hole is huge, about 1 1/2" ID.

[gumpy]

if the hole is on the curved end, I think I'd cut a round piece of steel that will cover the hole, use a small body hammer to shape the piece over the hole, and weld the edges to the tank. That is assuming the steel in the tank is good and can be welded.

craig

[kyle4501]

My concern is for your safety & my opinion & advice to you is to

        FIND ANOTHER TANK!

Yes you can weld on it, it may last forever, then again it may not. Lots of us have pushed the limits of good judgement & were lucky to survive & tell the tale. You have to decide if it is worth the risk.


Not trying to be bookish or a KIA, but to shed some more light on this so you can make the best choice for your needs ------

You are dealing with a thin walled pressure vessel. The steel in it is highly stressed when under pressure.

There is a very good likely hood that the inside of the tank is pitted. All that pitting combined with the patches will cause stress risers that may cause a catastrophic failure (think bomb & schrapnel).

In college, one of the engineering professors was a real hands on guy & saved the field failures he investigated to show what some the textbook failure theory looked like in the real world. It made a lasting impression.

Have you asked Luke for a tank? I have stumbled across some very good air tanks for my 4501, so there is hope for a more popular coach.

If no luck in finding a good used one & you can buy a new tank & have the needed fittings (from the old tank) added to the new one by a certified (in pressure vessels) welder. (The new tank won't have any pitting or rust inside to worry about.)

Good luck & keep us informed of how it works out.
kyle4501

[coachcrazy]

you should probably replace it, you dont wanna start rolling the dice when it comes to your life. i have to assume its the originial tank on the bus, look at it this way its  had a long life of 52 years in service on a bus(could have been made a few years before it was installed).  Retire the tank and get a new one and not have to worrie about it for another 52 years

[boogiethecat]

I have to agree, your tank is most likely telling you it wants to retire.  No, welding it probably won't result in your bus being launched to the moon or something of similar ilk,  although it could result in an unexpected stop somewhere on the road (Psssssssh goes the tank, on goes the brakes) but if there's even one rust-generated pinhole in it, it's very likely there's a lot more of them right behind it.  Since we're talking about 100psi here, if you really want to weld it and keep it, maybe consider having it hydro'd after you're done.  If it passes, well.... but if it doesn't, listen to what it's trying to tell you.

Personally I'd go to the trouble of finding another or even making another.

There's lots of air tanks out there... I bet with some looking you could find one that'd work fine.  YOu may have to weld in some new fittings... even propane tanks would work well as they are designed to work at 200-300psi.  I'd much rather see you cut a *good* tank in two, make it the size you need and reweld it, than piddle around with a 60 year old rustbucket....

[Dallas]

If I remember correctly, it's against federal regulations to weld an air tank. I may be mistaken, though it would leave you open to a lot of liability in case of an accident.

[gus]

I just got a quote of $391 for the tank but shipping from the East Coast will be a killer.

I know it is unlawful to weld fuel tanks but didn't know it was for air tanks.

I'm trying to find one closer to home to avoid that shipping cost.

[boogiethecat]

I think it's probably unlawful to weld any tank that has pressure in it.. That said, someone welds them or they wouldn't exist.  But those guys are certified welders for the application and they test & inspect them 100% after the welding's done.   If I were going to try it, I'd want to be a darned good welder in the first place, and then have it hydro'd at least.  But I agree that doing it yourself may have it's liabilities. 

How big's the tank?  I have a pretty decent guy who does my shipping if it's too big for UPS... maybe he can give you a decent freight deal??? 

Hey ONLY 4 MORE POSTS AND I DON"T HAVE TO BE A NEWBIE ANYMORE !!! 

[Busted Knuckle]

Hey ONLY 4 MORE POSTS AND I DON"T HAVE TO BE A NEWBIE ANYMORE !!! 

Hey slow down Gary! Don't wanna give up yer youth too soon they're already calling me a Sr. an I'm only 40! LOL! BK

[Hartley]

Air tanks fall under the ASME rule as I remember but might be wrong.

something like,

"Any tank that is used for pressure must pass a static test and must not have dents or patches."

Sorry, I saw that somewhere...

I know that I have been told by LP Gas people that it is illegal to fill a rusty or dented LP tank
or to them even one that has been repainted in a sloppy manor.

I would not trust my life or safety on any air tank or LP gas tank that has the remotest chance
of failing while under pressure. Especially one that I repaired. The liability factors are just too great.

I used to scuba dive and one time while getting tanks filled a guy had one that had a heavy scratch and ding
in the side of it. The air station refused to fill it and removed the valve then bashed the threads so that a valve
could not be installed. Most scuba tanks used to be filled in a tub of water which was a safety item so that if the tank
ruptured the water and tub would take the worst damage and not the guy standing at the control panel.

[86neoplan]

personally, I would not even play around with a safety sensitive part like brakes.. that price for a new tank is way less than the value of human life, which there is no price for. If you plan on keeping the old girl, give her a new tank.

shawn

[Clarke Echols]

Call a salvage yard that tears down big rigs (as in 18-wheelers).  They usually have a bunch of old air tanks around the yard.  Give them a diameter and length and they may have a suitable match.  Probably won't cost more than $5-10.   Western Truck Salvage (I think that's the name) in Denver (actually Henderson, CO) does it all the time.  The ports for connecting may be different, but if the size is close, you should be able to easily adapt.  Try for newer truck models, not something from the 1960s.  Big salvage yards get a lot of fairly new rigs from highway accidents.

(gee -- and I thought maybe I'd get rid of this "newbee" thing at 25...)

Clarke

[DrivingMissLazy]

Nope, Clarke. Not till 50 unfortunately. You just have to get on here more often with some of your Pearls of Wisdom!
Glad to see you posting again,  BTW
Richard

Call a salvage yard that tears down big rigs (as in 18-wheelers).  They usually have a bunch of old air tanks around the yard.  Give them a diameter and length and they may have a suitable match.  Probably won't cost more than $5-10.   Western Truck Salvage (I think that's the name) in Denver (actually Henderson, CO) does it all the time.  The ports for connecting may be different, but if the size is close, you should be able to easily adapt.  Try for newer truck models, not something from the 1960s.  Big salvage yards get a lot of fairly new rigs from highway accidents.

(gee -- and I thought maybe I'd get rid of this "newbee" thing at 25...)

Clarke