# Welding a propane tank



## cheapsx (Aug 19, 2010)

For those of you that have done it, what welding procedure did you use? For ARC what rod and did you preheat the area to be welded? For MIG what wire was used? My only choice for myself is ARC because my MIG isn't big enough for the job. I want to do it once and correct so I can move on with the project.


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## vvvv (Aug 19, 2010)

gotta make sure theres no residual volatiles be4 welding!


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## oldspark (Aug 19, 2010)

Wheres Kenny when you need him, 7018 may be a good one to use, and as blimp stated you need to be safe, I assume you do know what you are doing which surprises me you ask what rod to use. Do a google search on welding propane tank and make up yur own mind as how or if yu want to do this, pretty easy to blow yur face off.


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## chuck172 (Aug 19, 2010)

Ac or Dc?


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## Dune (Aug 19, 2010)

Asuming that you have at least AC, weld with 1/8" 6011, 6010 if you have DC. 
Before touching the tank, make sure your weld can pass a bend test. If you don't know what a bend test is, or how to execute one, do not do this welding yourself. 
The fact that you don't know which rod to use causes me grave concern about your ability to safely proceed.


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## oldspark (Aug 19, 2010)

Why 6010 or 6011 they are deep penatration rods, he would be better off with a 7018 or even a 6013, 6010 works on dirty metal but why use it here.


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## Dune (Aug 19, 2010)

oldspark said:
			
		

> Why 6010 or 6011 they are deep penatration rods, he would be better off with a 7018 or even a 6013, 6010 works on dirty metal but why use it here.



Exactly, 6010 and 6011 are both deep penetrating rods, that is why they are used by pipe welders, has nothing to do with rust. Don't you want your pressure tank fittings to have been welded with sufficient penetration?


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## cheapsx (Aug 19, 2010)

Yes I know what I am doing to a certain extent. The tank has been open and dry for years. I wasn't sure of what kind of steel these were made of so I was on the fence for using 6013 or 7018. I only have AC and if it's mild steel I will most likely use the 6013. I did do a google search but the answers come quicker from this forum. Thanks for the quick responses.


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## Dune (Aug 19, 2010)

By the way, never weld anything structural or especialy pipe with 6013. 7018 can be used as a cap pass over 6010 for large pipe.


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## Dune (Aug 19, 2010)

cheapsx said:
			
		

> Yes I know what I am doing to a certain extent. The tank has been open and dry for years. I wasn't sure of what kind of steel these were made of so I was on the fence for using 6013 or 7018. I only have AC and if it's mild steel I will most likely use the 6013. I did do a google search but the answers come quicker from this forum. Thanks for the quick responses.



Don't do it! Use the 6011!   ^013 is absolutely NOT to be used for pressure vessals.


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## oldspark (Aug 19, 2010)

I would go with the 7018 much better choice than the 6013 for what yu are doing.
E6011very similar to a E6010 but will run well on AC…This electrode is used for all-position AC welding or for welding on rusty, dirty, less-than-new metal.


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## Dune (Aug 19, 2010)

cheapsx said:
			
		

> Yes I know what I am doing to a certain extent. The tank has been open and dry for years. I wasn't sure of what kind of steel these were made of so I was on the fence for using 6013 or 7018. I only have AC and if it's mild steel I will most likely use the 6013. I did do a google search but the answers come quicker from this forum. Thanks for the quick responses.



Please, please, the few welding rods needed for general welding are easy enough to learn and understand. Knowing what you are doing to any extent requires this minimum amount of knowledge for your own safety as well as those around you.

For AC welders, here are the basics. 

6011. General purpose, fast freeze, slow fill, deep penetrating, useful for poor fitup, often used on dirty rusty metal due to good penetration properties, DESIGNED TO RUN ON AC.

6013 deigned for sheetmetal fabrication, primary purpose smooth atractive welds in thin metal. Low strength due to poor properties of penetration.

7018-AC structural high strength, low-hydrogen, fast fill, slow freeze. Use only on clean metal, 
welds best uphill, preheat heat metals to 300-400 degrees for best results.


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## oldspark (Aug 19, 2010)

We can find things all day long, 7018 is recomended for strength applications and I assume he will clean it before he welds it.
Just to add to this, you already found your answer so pay no mind to me, I just like a good discussion once in a while, dunes rods may well be the choice for some welds with the 7018 being laid on top, personaly I hate 6010.


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## chuck172 (Aug 19, 2010)

7018 is good for a tight fit only. No gap. 
Your not a welder cheapsx. Safety is my main concern. That's a bomb your lighting up.


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## madrone (Aug 19, 2010)

This is a vessel for flammable gas under pressure. It really should be welded by someone with lots of experience.


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## cheapsx (Aug 19, 2010)

I am not a pro welder and I don't like the 6010 from experience. I have used 7018 in vertical up deep v type passes. I have used 6013 a lot and it runs good in all positions. I have a selection of all of the above and will test any work I do before it is in service. Just me but if I used the 6013 I would v it out and make a few passes. The 7018 I would run tighter. But I am not against running 6011 either. I was really wondering what these things are welded together with when they are made. I have taken welding classes all be it years ago so it's been a while since I have actually read a book regarding what these rods are designed for. For economic reasons I am going to do this myself. I don't even know if the tank will make it in this year. I will find the welding books I have and read up on rod selections. I know this has to be done right and 500 gallons of water is substantial, but this tank will have a relief in it for 30psi. These LP tanks are designed for 250psi. I certainly don't want trouble with this and will test it well above the 30psi. Again thanks for the advice and input.


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## kabbott (Aug 19, 2010)

Dune has given you good advice IMO.

Ac 6011
Dc 6010
They aint pretty but they create good sound welds and are easy to control in ANY position. Should be the first electrodes anyone learns to use...

Not sure but the tanks were probably originally mig welded, spray transfer... not something you will do with a small mig welder.


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## zoecat (Aug 20, 2010)

cheapsx


http://www.millerwelds.com/resources/tech_tips/stick_tips/


http://en.wikipedia.org/wiki/Spark_testing_metals


the miller site will show you what the rod numbering system is, tensile strength, rod welding position etc.
the second wiki site will show you a crude way to see what the base metal is.
i would do a web search on propane tank construction to find exactly what the base metal is.
as the other member said the tank must be free of all residual propane and explosive gases.
i saw somewhere on the forum that the members were using something to add to water and fill the tank that rendered the propane and anything in the tank explosive inert.
if the tank base metal is 60,000 tensile strength you could weld the tank with any rod that was equal to the base metal tensile strength or greater. 6010,7018, 120018 ect...if the tank was 70,000 tensile strength a 70 series rod would be the lowest you could weld with. when selecting a welding rod or wire it has to be equal to or greater than the base metal.
remember when pressure testing the tank for leaks to hydro pressure test it with water not compressed air. 
hope this helps somewhat.

zoecat


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## salecker (Aug 26, 2010)

Hi
 I just got a couple of propane tanks for storage.I was told that once the tanks were open to air they would be safe to weld,unlike an old gas tank.
 Just wondering what are you welding on the tanks?Extra or different opening's?
 And what is the differance with testing with air or water?
 Thanks Thomas


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## cheapsx (Aug 26, 2010)

I need extra fittings in mine. I know everyone's concern is safety but my situations a little different. My tank has been open for year and spent a long time being used as a some sort of liquid fuel tank (diesel or kerosene), and had been drained and rinsed since that. So I will wash it out, to help rinse out some rust, and go to work on it without worry.


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## ewdudley (Aug 26, 2010)

cheapsx said:
			
		

> I need extra fittings in mine. I know everyone's concern is safety but my situations a little different. My tank has been open for year and spent a long time being used as a some sort of liquid fuel tank (diesel or kerosene), and had been drained and rinsed since that. So I will wash it out, to help rinse out some rust, and go to work on it without worry.



A neighbor here abouts all but killed himself welding on just such a tank.  Rinsed or not rinsed, once it's been used for liquid petroleum products there's a problem.

What I did was to put a dip-tube exhaust pipe in one port, and piped-in exhaust from a car into the top through another port.  The theory was that the warm exhaust would displace the cooler air in the tank and after a while there would be predominantly exhaust in the tank.  

I speculate that I might have accomplished the same thing by pumping in enough air such that the rate of air coming into the tank would guarantee that the contents of the tank were too lean a mixture to ignite.

None of which constitutes advice.  I'm merely reporting a couple of anecdotes.


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## jebatty (Aug 26, 2010)

Wish I could tell you the rod. I had my neighbor do my welding. He had an old AC/DC stick welder; operated off a 50 amp breaker on my main panel. He cut the holes with hole saw and then welded in two 2" couplings. No pre-heat; two passes; works of art. His trade is welding 3000 psi steam pressure lines at the nuclear and coal power plants in the area. When I asked him if I needed to pressure test the welds, he smiled and said "no."


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## salecker (Aug 26, 2010)

Hi
 If your tank had diesel or kerosen in it you should be very carefull.A friend of mine blew himself off a ladder when a tank he was welding blew the end off,it was an old fuel tank,hadent been used for diesel in a few years,he did have exhaust from a truck ideling in it.It was a 500 gallon tank and it blew the end right off it.I would get a tank of argon and fill it with argon befor i welded on it.
 Thomas


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## chuck172 (Aug 26, 2010)

Exhaust gas is not a good idea. If you have a rich mix, or a miss resulting in unburned gas, BOOM!!
But I know, so and so did it, no problems, he's still alive.


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## zoecat (Aug 26, 2010)

salecker said:
			
		

> Hi
> I just got a couple of propane tanks for storage.I was told that once the tanks were open to air they would be safe to weld,unlike an old gas tank.
> Just wondering what are you welding on the tanks?Extra or different opening's?
> And what is the differance with testing with air or water?
> Thanks Thomas



http://www.eng-tips.com/viewthread.cfm?qid=112658

thomas it is my opinion to test with water not air, read the thread from a bunch of engineers who have tested with both water and air and make your own decision.

zoecat


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## Dune (Aug 28, 2010)

What I do is rinse them out real good with water then detergent and water, then rinse then a couple more times for good measure. I often rig a blow dryer to blow into a tank until it is dry, having welded a lot of automobile gas tanks. Purging a tank with argon while welding is an excellent thing to do as well, for multiple reasons.


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## salecker (Sep 14, 2010)

Hi
 A friend of mine that is a welder,and presure welder came buy yesterday and welded the fittings on my tanks.They had been scraped by a propane company.He used a hole saw to cut the openings,stick welder to do the welding.After he cut the holes he waved a lit torch under the tank "just in case".The tanks had been open to air since i picked them up a couple of weeks ago.Very little danger if they have been open to air he said.This is the same guy who got blown off a fuel tank he was welding last winter.He said the tank that blew was old and rusty inside,supposadly haden't had fuel in it for years,seeing the rust he thought it should be harmless,blew the end right off the tank and was laying about 50ft from tank.
 So be extra carfull if there has been any petroleum in any tank you need to weld.
 Thomas


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