Welding on a compressor....with POLL!!

[e-tek]

OK ya crazees!! The POLL is posted. If ya also want to add more crazee comments on why you would or wouldn't, or shouldn't, weld on a compressor, or, if you just want to tell us your expert qualifications on the subject, your vessel-certifications, and maybe your Local Pipe-fitters Union number, please do so!

 

[s_ontario]

need to add one

I think your a idiot for even thinking of welding on a compressor tank but for god sakes if you do take pictures.. we will send flowers

 

[Tigwldr]

I weld one high pressure boiler tubes all day. We hydro test at 4000psi and above. An AC tank is no problem to me.

 

[pgreen]

I do a LOT of critical TIG welding on race cars. I'm not sure how this is so much different than a highly stressed 4130 chromoly suspension member. Sure it is a pressure tank, but how is this really more critical of a weld than a suspension member or roll cage on a race car going 140 MPH? If a suspension member weld breaks, the car WILL crash. Into what, or how bad is another question.....but either way, it isn't going to be good!


BTW e-tek, ya just HAD to stir the pot again with this poll! Should be entertaining to say the least.

 

[Red Green]

I would have voted for.

If it has a rust hole there is no point in welding because its time to get a new tank.

 

[NASTYZEN]

Good one e-tech!LoL Should have a couple more choice options for your poll,but it's a good start.
Btw NO! bad idea! I can weld anything but if someone walks in my shop with a compressor tank to be fixed,I for sure will turn him away.
And if my compressor tank ever needs welding I for sure will torch a big hole in it so none of you guys will get the urge to (fix it)
My life is worth more than the bigest mother of all compressors!

 

[ripsnortMN]

You forgot one...
Only dumbshits weld on compressor tanks.

 

[djjsr]

Only dumbshits weld on compressor tanks.

Bumper stickers and T-shirts will be available soon.

 

[srmofo]

Be more specific in the question. Does it need a bung installed because all the others are somehow damaged or being used? Is it cracked? is it rotted through?

Personally I wouldnt do it because I can barely stick 2 pieces of metal together nicely.

Even if I could, I sure as hell would not do it for a customer. Some exceptions might be made for close friends with proper pressure testing. You can probably pick up another tank though for that price. Just a guess, I ve got no idea what pressure testing costs, but used tanks are cheap

 

[tatra]

rust holes in tanks?......of course you don't weld it, that's what selftapping screws are for...........amateurs..........

 

[waltmcq]

I have a friend that is a truly amazing welder. Built boats, built formula one chassis, and welds on some super valves and pumps for research labs. I'd go ask him to see what he thinks first.
But my thinking is just turn the heat down a little and weld it up.

 

[e-tek]

Be more specific in the question. Does it need a bung installed because all the others are somehow damaged or being used? Is it cracked? is it rotted through?

It's a tongue-in-cheek take-off on another thread, where someone asked about welding a compressor leg back on.....http://www.garagejournal.com/forum/showthread.php?t=84949

 

[koditten]

Must...resist the...urge to post...feel the need...to prove...how superior I am to...others. My opinion...is the only one that...counts.

Just kidding. I loved that "other" thread. It did piss me off at times, but it sure did show how rabid some could be with their opinions, myself included. Both the nays and yea's were pretty vocal.

 

[A_Pmech]

I'm confused...

There's no "I like bacon" option!

 

[rwhite692]

If anyone thinks that the meatheads on the production lines at the compressor manufacturer who MIG weld legs, wheel brackets, motor mounting plates, and other various doodads onto the outside surfaces of compressor tanks are the same caliber of welder who welded the tank itself, ie, the seams, bungs, etc, you are dreaming.

Virtually all compressor manufacturers buy the "raw" tank as an ASME certified / pressure tested item from a supplier, and they take care of customization items themselves.

The surface welding of these little items probably isn't even registering penetration a quarter of the way into the tank metal thickness.

I think we should ask the OP to weld his broken leg back on, and then, sacrifice his compressor tank for a cross sectional metallurgical analysis.

 

[Red Green]

I think we should ask the OP to weld his broken leg back on, and then, sacrifice his compressor tank for a cross sectional metallurgical analysis.

Now that sounds like a good idea. I am going to be on the lookout for a cheap compressor at an auction. So I can do some welding and a dissection.

 

[wishihadatalon]

Too many variable to really determine if it is worth it.

First is base material. Is it normal low carbon steel? If so, welding with have NO metallurgical effect on the material. You could quench it and nothing will happen. I'd feel perfectly comfortable welding on it given my experience welding.

Second, cause of failure. If it is a crack, there is no point. Chances are that it will just crack again.

It should be noted that technically work should be done by code. A flaw on a weld is the starting point for material failure. A few of my welding professors told us a story about a maintenance man who welded a small bracket to hold a device onto a welding rig before they took it out to sea. Here is the story http://en.wikipedia.org/wiki/Alexander_L._Kielland_(platform)

There is a lot more to welding than pulling a trigger.

 

[Test Tech]

I don't see any reason for a good welder to not repair a tank, my reasons are as follows.

1. The welders at the off shore plants where these things are made are no better than most of us.

2. The tank is exposed to fatigue due to loading and un-loading cycles, like many of the other welds many of us do every day. I don't know about you guys but most of my welds live through everything they get exposed to everyday, including loads I never intended.

I will agree with some of the cautionary statements of other posters.

1. Know if you are a good welder or not, and be realistic about it.

2. Before you weld it examine the base metals condition carefully.

As for the origional poster to the thread that this poll arose from: it looks to me like the origional weld was not very good (overseas expert welder! ) and I'd definetly repair that myself.

 

[e-tek]

Some interesting results thus far!!
"Most" of the resposndants (me included) would just weld it up and hope for the best.....That line of thinking was good enough for my Dad (RIP), and it's good enough for me.

 

[1Garageman]

I weld one high pressure boiler tubes all day. We hydro test at 4000psi and above. An AC tank is no problem to me.

That is a shitload of PSI!!!

 

[nehog]

Just why everyone seems so resistant to a post weld hydrostatic test is beyond me... Is everyone that cheap that they don't want to spend a few dollars?

 

[djjsr]

I weld one high pressure boiler tubes all day. We hydro test at 4000psi and above. An AC tank is no problem to me.

You're the guy that could probably easily repair a tank and never have a problem. But the guy that started this whole discussion (in another thread) is an occasional welder with a fluxcore machine from Harbor Freight. A bit of a difference.

 

[1Garageman]

You're the guy that could probably easily repair a tank and never have a problem. But the guy that started this whole discussion (in another thread) is an occasional welder with a fluxcore machine from Harbor Freight. A bit of a difference.

Very good comparison!

 

[Orangestang]

I would weld it as long its not rusted or cracked otherwise it will just return......Btw I'm union sheet metal worker with weld certs up to 1/2" Carbon steel plate in all positions MIG,and up to 1/8" on Stainless Steel TIG. Been doing this on and off for 20yrs now.

 

[christopizza]

I'm a hobby welder and I'd take it to someone qualified to weld it if there are not other issues with it. I spent alot of time inspecting welds on pressure vessels while I was designing robotic welders for use in the nuclear world...

I keep things going as long as possible and reasonably safe. Before I put effort into repairing anything I think to myself --l Something had to make the tank fail -- if it is part of a weld -- how confident are we that the other welds are ok? if it's metal fatigue -- we're likely going to see similar cracks soon in other areas.

Chris

 

[Dragster Racer]

I had no idea the holy rollers were at it hard. I should have checked out the first thread.
What is the worst case senario here? I have seen many pressure related metal failures, and seldom is anything thrown through the air. The only damage is where the rips are. I don't plan on hugging my compressor for hours on end. Heck, I don't even like being near it. It's loud. If this abundance of caution were used everywhere, nothing would ever get done or discovered or created. If you don't want to take ANY risks, stay away from me. You will be uncomfortable for sure. But things will get done.
Just helping stir the pot for ya.

 

[crewchief888]

as mentioned before, too many variables.

if it was rusted through, no i wouldnt weld it.
if a bracket or mount weld was broken, yes i would
would i do the same for someone else? probably not
would i do it for a commercial/shop application that runs high line pressures? no

in 2535 years ive been working in heavy eq and machine shops, ive only seen one compressor tank blow. it was a twin tube, gas engine compressor in a service truck.
tank rusted through and blew with 175 psi.
we junked the tanks, and kept the engine and compressor.
next day, the tanks were missing from the scrap dumpster........

 

[Kilo70]

I voted for Take it out in an open field and Blow it up.

 

[djd99]

Depends on the condition of the tank if it's a 8 out of 10 Hell ya but I have the equipment and experience to use it. As to the other thread his tank was well worth fixing.

 

[JSGAuto]

I welded on a tank I used for my Onboard air setup, and plan on doing so again (for my other truck).

This is common since, are you skilled enough? Do you have the proper equipment? Is the tank in good shape? ..............If no, then its not for you!


I agree with one of the above posters said about welding on critical structures....its the same deal! Don't be a hack, and it will be OK!

 

[smooth72]

No matter what, I would use it as an excuse to get a new 7.5 hp 80 gal Eaton
compressor. No... I have not been dreaming about one, my 20 year 5hp 60 gal Sanborn keeps on chugging along. I guess I should not complain. I run mine hard and still works, just have to let it catch up time to time.

 

[slip knot]

rust holes in tanks?......of course you don't weld it, that's what selftapping screws are for...........amateurs..........

Ya gotta wrap some white telefon tape round the threads afore you screw it in or its gonna leak

 

[Ben Buck]

Can you say KA-BOOOOOM!!!! Film at Eleven!!

 

[e-tek]

Well I for one am thrilled that - on a site full of guys who DIY - 50% of the respondants would weld it up. Interestingly, "reasonable" people that wouldn't weld it are (a distant) second!

 

[digdug18]

I've done it with a stick welder, worked great.

 

[Steevo]

The poll needs another option:

Hold my beer while I weld this . . . .

 

[rwhite692]

as mentioned before, too many variables.

if it was rusted through, no i wouldnt weld it.
if a bracket or mount weld was broken, yes i would

LOL, The OP indicated that the leg broke off of the surface of the tank, that is what started this whole ridiculous discussion. From the pics he provided, the original weld looked like ***.

 

[e-tek]

The poll needs another option:

Hold my beer while I weld this . . . .

How about: "Hold this, while I drink my beer"!!

 

[Brad54]

Well I for one am thrilled that - on a site full of guys who DIY - 50% of the respondants would weld it up. Interestingly, "reasonable" people that wouldn't weld it are (a distant) second!

I found that same tidbit to be very scary! Especially with the thread about someone's tank blowing up in his garage and breaking arms, legs and ribs.

Seems like the perfect example of "Common sense isn't."
I think too many people aren't actually putting any thought into an answer when they ask "What could go wrong?"

-Brad

 

[e-tek]

Seems like the perfect example of "Common sense isn't."
I think too many people aren't actually putting any thought into an answer when they ask "What could go wrong?"

-Brad

But you have to take the Law of Averages into account - in whatever you do. Otherwise you'd be paralyzed by the fear of "what could happen". Every day you (we all) do several things that could end in injury or even death. Some people "cheat" death their whole lives - it's the law of averages that makes it reasonable for them to go on.