Any tips for welding on my fuel tank?

[busshawg]

Little leary about asking after the last welding question I had but here it goes. I am going to drill a hole in my fuel tank to accommidate a fuel pick up line , and then weld the nut it is attached to, to the fuel tank. I will be using a vacuum and also be using plenty of grease on my drill bit and will be going slow. As for the welding I only have 1/4 tank of fuel and will be welding at approx. at the same level as the filler cap. Anything I should know. Do I leave my fuel cap open while I'm welding? etc

[Len Silva]

I wouldn't weld on the tank at all.  Install your fuel lines in a steel plate, then screw it over a hole you make in the tank.

http://users.cwnet.com/~thall/fredhobe3.htm

[zubzub]

My but Len had a nice clean simple solution!   I would never have thought of that.  A little gasket cement to seal the deal maybe.

[gm4106]

Use a Bulk Head fitting. I use them when plumbing my fuel lines for the generator. Very easy just drill a hole and bolt back together.

[Lonnie time to go]

my  friends father was welding a gas tank and guess what.  He now has burns all over his body that will never get better.
My thoughts are its just not worth it. 
Get a pro to do it for $20.00

[Tom Y]

Any tips?  DON"T  I also know someone welding a truck fuel tank that got burnt. I wouldn't ask someone else to do it  either. If you want it welded remove and have steam cleaned first.  Tom Y

[boogiethecat]

I agree with all the "don't weld it" people.  That said, the way to weld it if you must, is to empty your tank to at least half and then slowly let off a good sized CO2 tank into the fuel tank, then weld away, keeping the CO2 flowing as you weld..  The CO2 is heavier than air and will create a non-flammable "blanket" over the fuel.  Needless to day the outside of the tank must be spiffy clean so you don't catch a bunch of grease on fire.

This method is used by gas station maintainance crews to weld new bulkheads onto partially full underground tanks of gasoline.  I was watching a guy do this, listening to his arc-blobs go "fizz-fizz" as they fell into the gasoline... I was quite interested in why we were still alive so I asked.  CO2 was the answer... he said he does it daily!!! Eeeeek

[JohnEd]

Everything Boogie said.


A friend of mine's Daddy used to repair underground gasoline tanks on a regular basis.  He ran a hose from his truck exhaust to the tank.  Said he ran it for 15 minutes and started welding.  Left the truck running all the while.  I had a friend of mine weld up my motorcycle tank.  Guess what?  He ran a vac clnr hose from his exhaust into the tank for maybe 30 seconds and welded away.  I offered to wash the tank with soap and water but he said he would still flood the thing with fumes and he declined my offer.  Needless to say I had missgivings.  SPOOKY!  But if I had to do it and had no choice, it is info I would put to use.

John

[luvrbus]

boogie, saw that method used for years at the refineries in Texas also saw exhaust from the gasoline truck on small tanks. When I worked for Tennessee Gas we would flow natural gas through a pipe burning a flame at the 2 joints to be welded if there was no flame no weld                     good luck

[prevost82]

Yea ... Boogie .. that's how we use to weld tanks up.

[muddog16]

I'm on my Iphone and this isn't easy!!!!

Welding on a fuel tank of any size or type should be left to a professional!

If that isn't clear enough then you are truly a busnut or crazy!

1.  Tank must be totally empty!

2.  Wash the tank out with soap and water several times!

3.  Fill the tank completely full of water!

4. Use a nitrogen purge!

5. The tank is ready to weld!

6. I know that this won't deter some, so one last point is make sure we know where to send flowers!

[orfunauto/Darrell]

I've been building street rods for thirty-plus years and have welded on many tanks.  My practice is to drain the tank, run exhaust from another car or truck through a 2" rubber exhaust hose for thirty minutes, then weld.  Never had a problem other than getting the moisture out of the tank from the exhaust.

[Chopper Scott]

OK guys. I am a welder and have welded countless times on fuel tanks. From aluminum airplane tanks to 20,000 gallon diesel tanks. As has been stated welding on anything highly flammable such as gasoline tanks I always use CO2 to remove the oxygen. I've actually brazed holes shut with a small candle type flame coming out of the hole!! It makes the customers stand outside!!! But diesel is not as flammable a product such as gasoline and I weld on them all the time without any CO2 or anything else. I've tigged aluminum tanks while still half full and still on the semi. I weld on steel tractor diesel tanks all the time without rinsing them and such. I weld bungs in supply diesel tanks all the time. The only issues I have ever had with welding on a diesel tank is cutting a hole with a torch in very large (10 or 20,000 gallon) storage tanks to weld bungs into. The old residue in the tanks will eventually begin to burn with the hotter temps the torch creates and it causes the air to expand at a very fast rate. The expanding air blows out of the hole you cut and can scare you but eventually the fire burns out the oxygen in the tank and the air cools which starts a reverse suction of air back into the tank. You have to get used to it. But as far as small diesel tanks like in a bus and such you can just weld it. I always am wary during the winter of truck tanks however as some truckers will cut their diesel with gasoline to keep from gelling in bitter cold. Like I said. I do this all the time. Later

[jdr]

Scott said it best. One side note, beware of empty tanks, no fuel cap and static electricity. We learned this the hard way one day when one of the guys removed airplane fabric from around the fuel tank on one of the wings. You guessed it, the electricity jumped in the tank and turned the inside of the hanger orange for about one second. Fiberglass is still in the ceiling. Fortunately the guy was not in the path of the explosion or it could have been bad.  Jim

[Sojourner]

Your post may save either you or others life. This is a good reminder to anyone that attempted to repair fuel tank and post every now and then.

To whoever wants to weld a fuel tank via sparking devise or welding torch is to remember this...Those that didn't live or badly injured is not able to be on this post to tell you about their stories.

I happen to be fortunate to be here to tell you my story. One day in my teen, my dad's combine engine's gas tank soldered seam on top of tank was leaking. I decide to remove it from the combine to flush it with hot soapy water. Twice I did that and hot water rinses it well but still smell gas fume. So I fill it water to almost to the top...about 1/2″ below the seam. Heated my solding iron via blow-torch which was on my right side about two feet from tank. Using acid-cord solder and iron to heat seam hot enough to melt...all of sudden...the next thing I know it went boom and learn later the seam is now ripped open. I smell hair burned and my eye brow was falling like a dust and hair was torched. That is when I learned it was an explosion I have just experienced. I think I was wearing glasses then to save my eyes from hot solder or whatever. Praise the Lord!

About purging tank...While working at GM Tech Center in Warren, MI...they use chemical to rid of combustible mixture with compress air for about 45 minute. Then have the security officer to probe check for combustible fumes to give an OK tag for welding. Back than, the only way to safely say it non combustible for repairing work or for storage purpose.

Every time I read the post about to live tell you "it work me"...it make my cringe think that it has not happen to them....yet.

Here one who lost his friend.
Welding on gas tank from the Hotrodders Bulletin Board

Suggest using Lin's suggestion or any non spark or torch weld method.

Or like what muddog16 suggested....Welding on a fuel tank of any size or type should be left to a professional!

Sojourn for Christ, Gerald