How to weld a tank on a fuel oil truck

[acesneights1]

I have a few questions. I tried the search for Tank welding but didn't come up with what i was looking for. I have a fuel oil truck. The tank is aluminum. It's leaking where the baffle inside meets the bottom rail. this is common for older tanks.
My questions are;
what safety precautions would I need to take to go in the tank and weld it. Does the entire tank need to be washed out ? i don't think the place I took it once before did that. Also what kind of fresh air setup would I need. I emptied the tank once before and left it with a fan venting all day and nearly passed out from the fumes after like 10 seconds. Is this more than I can handle safely ?
second Question. why does it have to be welded from the inside ? why can you weld a tank on the outside. everytime I have had a tank repaired they always went inside and did it. Just never understoofd why.
Thanks.

[El_Lloydeo]

dunno about question 2 but dry ice is a good way to weld on a tank that has fumes in it. dump some hunks in there and wait for it to start coming out the hole at a nice and steady pace. you can purge it with argon so i have read. i even filled one with water one time and did it. have to make sure to get it all out but worked fine for me.

[El_Lloydeo]

are u talking about a very large tank you can get inside? because i was talking about a gas tank. like for a car.

[tresi]

You're going to have to find a professional steam cleaning service. If the have a steamer like you can find at Northern Hydraulics that's not good enough. It's going to take some like an oilfield pipe and tank steaming truck and it's going to take most of the day.The entire tank must get hot during the steaming process. It must be checked with an explosive gas meter not only after steaming and again before entering the tank to weld. The steaming company will just provide the steam for however long you pay for. It's falls on you to make sure it's safe to weld.

[Dualie]

Um if your talking about a placarded fuel delivery truck I think the FMVCSA wouldn't like you repairing the tank yourself.

God help you if they found out you did your own repair job on the tank itself.

[dave powelson]

Originally Posted by acesneights1

I have a few questions. I tried the search for Tank welding but didn't come up with what i was looking for. I have a fuel oil truck. The tank is aluminum. It's leaking where the baffle inside meets the bottom rail. this is common for older tanks.
My questions are;
what safety precautions would I need to take to go in the tank and weld it. Does the entire tank need to be washed out ?
**yes

i don't think the place I took it once before did that.
***I'll bet u doughnuts--they did**

Also what kind of fresh air setup would I need.
****either really good flow thru air changing-monitoring the air for 02 levels, or be on your own air. I go in on my own air, plus air change flowing.

I emptied the tank once before and left it with a fan venting all day and nearly passed out from the fumes after like 10 seconds.

*********You have overlooked the fact that the argon gas you'll be using for aluminum welding will kill you--if you don't have a fume explosion first.

Is this more than I can handle safely ?
*****Yes this is more than you should tackle. From your questions, this is not in
your league.


second Question. why does it have to be welded from the inside ? why can you weld a tank on the outside. everytime I have had a tank repaired they always went inside and did it. Just never understoofd why.
Thanks.

******The baffle welds breaking can be for a bunch of reasons:
-poor design (often the case)
--tank cradle caused it, frame to cradle mounting defective, rough roads,
truck frame has damaged the cradle or cradle mountings
--the inside repair can include adding stiffner plates to the skin/baffle
connection, etc.
'Yours Truly' has done weld repairs inside 10,000 gal., aluminum flight line tankers for USAF.

El_Lloydeo's rambling about using dry ice, filling tanks with water--are just two
of the 49 other ways to have tanks blow. Next, someone will tell us to fill the tank with
exhaust gas. I've seen and heard it all. I can make a tank blow or not blow--can you?

[paweldor]

Take it to someone qualified, certified, and experienced to do the repair.

[acesneights1]

Thanks guys. Thought this was too much. My life is worth more than that. FYI the guy who repaired tank for me in the past swears they don't wash it out. He did cut a second hatch in it though on the other side of the baffle.

[acesneights1]

I actually just finished welding the saddle tank for the same truck yesterday and was nervous enough about that. I washed the crap out of it and let it vent for almost two weeks. Went smoothly. Did 5psi pressure test on it. Sat over night , no leaks. The big tank too much for me to handle safely. Steam cleaning the tank isn't the problem, it's what to do with the water afterwards. That's haz mat.

[dave powelson]

Originally Posted by acesneights1

Thanks guys. Thought this was too much. My life is worth more than that. FYI the guy who repaired tank for me in the past swears they don't wash it out. He did cut a second hatch in it though on the other side of the baffle.

I'm posting the comments and observations below, simply to alert some brave souls
that may see this thread and assume that one can weld in confined space, with fuel
fumes and it's 'Okay'.

-so he didn't wash out the tank, did he even bother to monitor LEL (Lower Explosive Limit)?

-did he monitor O2--for breathing atmosphere inside the tank?

-prolonged welding where the tank structure gets hotter, will begin to cook off more
volatile fumes. If there's not good air flow thru the tank--the LEL will go crazy.
I personally know of one local incident where a tanker had seen 4 hours of welding,
and then blew the steel roof deck off the building.

Some guys like to roll the dice--I don't care to.
I'm not going to breath fuel oil fumes, either.
[I lost my voice from JPTS (jet fuel for the U2) doing underground aluminum pipeline-hot welding repairs, for 3 days. Knowing that-now, I would/should have been on my own air.]

My guess is he just did a quicky job and got the h--l out of that tank.

[SundownIII]

I personally am glad Dave brought a degree of sensibility to this thread. Good advice based on real world experience.

With that said, I still wonder why there are posters who feel it necessary to comment on issues where they obviously have no experience.

Giving advice on welding fuel tanks, with no experience in the field, is downright dangerous and irresponsible. If you don't know what you're talking about, then don't say anything.

[specter]

Have a DOT certified tank welder do the job! It will save you alot of trouble in the longrun.

[acesneights1]

Believe me I am. I think the only reason I posted in the first place is to get some response and get the idea out of my head once and for all. I will watch very closely how they do it this time and report back. I am sure they don't wash the tank out because I remember looking inside last time and it was not washed. I think he vents it somehow which is why they cut the extra manhole in.