Welding on Diesel Storage Tank Steel

[gmason]

Thanks for all the great replies here. I haven't made any decisions yet and still looking for other experiences. I've stick and mig welded before and have taken classes in both.

I've welded nuts on bolts and that would basically be what i would be doing here. And while the bolt will get hot it doesn't get red hot. I figured as long as I did this outside in a vented area where the fumes/vapors wouldn't ignite from a spark from the stick I wouldn't do anything but warm up what ever is on the bottom of this tank. Maybe water, sludge, or diesel.

The tank is not leaking anything around or near the plug.

Here's a few pics of the tank and what's left of the square nut after it chipped off a 1/3 of it.

gary

 

[firedog]

Gary, there has been some good advice and some not so good advice posted. I'm not going to get in any flame war about who can or has done what, or what some 100 yr welder always did.
I've been in Hazmat response for about 20 yrs. and have been a part of cutting, drillng & welding on piping, tanks & storage vessels with various contents. The one key question that must always be addressed is: "Is there any other way to do this" if that answer is yes, then that is the route to go.
When is time & money vs safety. Safety should always win.

In your case, I think your best option is to drill out the plug, soak the threads with some liquid wrench (or similar) and use an ease-out type plug remover.

 

[AndyinIowa]

I grew up in a weld shop. We repaired diesel AND gasoline tanks. We always used a large shop vac on the tank to suck out fumes. The shop vac would run for at least 15 minutes before any welding occurred. Gasoline tanks were also flushed for 30 minutes with solvent and water. Minimum charge for tank repairs were $75.

That being said, I see no reason for the average homeowner to weld on a fuel tank. Take it to someone who will prep and repair the tank in a controlled envrionment.

 

[gmason]

I grew up in a weld shop. We repaired diesel AND gasoline tanks. We always used a large shop vac on the tank to suck out fumes. The shop vac would run for at least 15 minutes before any welding occurred. Gasoline tanks were also flushed for 30 minutes with solvent and water. Minimum charge for tank repairs were $75.

That being said, I see no reason for the average homeowner to weld on a fuel tank. Take it to someone who will prep and repair the tank in a controlled envrionment.

did you try to create a vacume inside the tank with the shop vac?
gary

 

[patrick_g]

a lil trick i learned from the old timers dont know if it will work in your situation but its to fill the tank with car exhaust. it pushes out all oxygen. no oxygen no explosion. been told dont have to worry about the water causing rust. it has always worked for me and dont have to worry bout the water cooling weld to fast and crystalizing it. just my 2 cents

Actually car exhaust doesn't necessarily remove all oxygen and there is no simple way to know when you have circulated enough exhaust to do as good as it will get. That is why I prefer water. It is a sure thing. I do let a small bubble of air rise to the top of the tank to eliminate direct water contact to the metal I am welding.

Another difference is that I have ACTUALLY welded a few gasoline and diesel tanks not just heard the good ole boys talk about it.

...And by the way... I am on the side of safety, absolutely. If there is a better or safer way, by all means use it. My comments were on how to weld it safely if it is going to be welded not a blanked recommendation that just anybody takek it on as a DIY project. You can also discharge a CO2 extinguisher into the tank to purge oxygen and other methods. I find water works good and is relatively cheap and I keep my CO2 bottle ready for its intended purpose.

Pat

 

[gmason]

I have been able to get rusted/frozen nuts and bolts off a different way. Use a very sharp air chisel and only use the corner or edge of the chisel ponting at the angle you want it to turn. Kinda like using your finger to turn it. Use the chisel to turn the bolt NOT cut the bolt. You can even guide the chisel using the hand not holding the air hammer. The shaking wont hurt. Wear gloves if you're worried. I've used this technique for years fixing cars, trucks, tractors, old motorcylcles and removing heating elements on hot water heaters. The vibration from the chisel causes the bolts/nuts to come loose and turn. It is so simple and effective it's hard to believe it works. If you don't have an air hammer use a sharp chisel and hammer. Just as effective but requires slightly more finesse. Be sure the chisel you're using is sharp so that it "bites". Dull ones won't work, just slide off.

Hello Matt. I tried your point with a chisel, unfortunatly it cut off all the square nut after 4-5 taps. It looks as though the plug is made of a cast metal and not forged/stamped. I can see some very pourous metal now. So maybe it would be easy to drill it out, cause that cast metal should be pretty soft. right folks?

thanks
gary

 

[calbrown]

in your pics it doesnt look like a fresh break

 

[Mundy]

Drilling looks to be a good choice. If you drill 2 holes you may be able to insert 2 bolts and use a wrench to unscrew the plug.


As for welding it, If full of fuel oil or diesel (NOT GASOLINE) welding below the fluid level is quite common practice. Fuel oil and diesel tanks get welded on all the time with fuel in them. Don't weld on a drained tank unless you address the fumes properly. I have been told that if you drain a diesel tank it becomes dangerous just like a gasoline tank always is.

By all means if you are not skilled with welding on fuel tanks I would say don't do it. Looks like you will have the issue solved with drilling.

That plug is most likely cast iron and would not weld anyhow.

 

[gmason]

in your pics it doesnt look like a fresh break

Yes I hit it quite hard with PB Blaster before the picture this morning.

But I tried the chisel method just before dark tonight and didn't get any pics from that yet.
gary

 

[shvl73]

As for welding it, If full of fuel oil or diesel (NOT GASOLINE) welding below the fluid level is quite common practice. Fuel oil and diesel tanks get welded on all the time with fuel in them. Don't weld on a drained tank unless you address the fumes properly. I have been told that if you drain a diesel tank it becomes dangerous just like a gasoline tank always is.

You're probably right, but it suprised me at the time. I know, I wouldn't do it myself.