SR-71 SS

iTrader: (2)

I plan on welding in a 10-AN and a 6-AN bung/bulkhead fitting into a metal tank on my 98 camaro. My questions are what needs to be done to prep the tank to do this safely? and would it be better to use a aluminium or a steel bung? thanks

v8bug

steel bungs for sure. I would drop the tank drain the gas and fill it with water, slush it around, and drain the water, fill again with water drain it again and let it sit for awhile and air out. Thats what I would do, but maybe theres a better way to remove the gas fumes?

Old Geezer

iTrader: (3)

the tank is steel, you won't be able to weld an alum bung on it, and vice versa.

as for safety, I always flush with purple cleaner, and then allow the hose to run water thru the tank, for several minutes. I've not "outrun the space shuttle" doing it that way, for 40 yrs...

A steel tank is likely to be galvanized. The coating must be completely ground off, in the weld area. Welding on galvanizing produces a poison gas.. BEWARE! If you see a white, powdery substance in the weld.. that indicates galvanizing was not completely removed...

SR-71 SS

iTrader: (2)

So after flushing the tank out( I assume when its clean to the point where gasoline odor isn't present its safe) a grinder/sander will be sufficient for removing the galvanized coating? and what if anything should I apply to prevent rusting at the weld site afterwords? thanks

Old Geezer

iTrader: (3)

use a fine sanding disc, and take the galv. off. You can tell when the coating is gone, as the area will change color..
[I use a "90* air die grinder w/ a 2" pad.]
Spray on galvanizing is available at autobody supply stores.
[I always have the tanks powdercoated.]

Don't forget to check for leaks!!
I plug the fitting, and with the tank sitting with the fitting down, dump a bit of laquer thinner in it..If there's a leak, you can dump the thinner, and the remaining will evaporate, so you can fix the leak.

Fire67

iTrader: (3)

I washed mine out with Dawn and water. Rinsed several times, left it to sit in the sun all opened up for a couple days, then dropped it off to my TIG welding guy with the sump.

He didnt complain, so it must not have been a problem.

Gary Z

My mother told me about a Swedish welder who was repairing a leak in a large gasoline tank. The tank exploded and blew the man clear across the street. Horrified observers rushed over to the man expecting to find him dead. Are you all right?, they asked. Yup, he said. I yust got out in time.

DRVETTE

Hey just wondering if you want a 10 an fitting and a 6an fitting in there dont weld it at all just put a bulkhead or fuel cell fitting with 2 washers on. I have used them in the past and they work flawless and dont leak.

smokeum99ta

iTrader: (15)

Welding on gas tanks isn't easy or fun. Make sure there is absolutly no gas fumes in it or it will ignite. I've repaired (or tried) a couple of tanks in the past only one was I suscessful with the other I just made worse with them igniting and blowing them up like a balloon causing more leaks. Good luck either way....

slick1851

Just dont die and come back with burns when your done, good luck brotha!

TTAWD

Dunn this to many of these to count.
Take your fitting and weld it to a clean
peace of 2x2 18 gage steel , a peace
of old car hood works grate.
Now take your tank and your 2x2 peace
of steel with your bung welded in it to
your local radiator shop, have the guy
vat your tank and solder your peace
to your tank. NO! it will not come off.
have the guy run a little solder around the
fitting weld.
The solder flows very well and will find
all the nooks and cranny’s and seal them.
The 2x2 patch will ad support to the surrounding
area. You can tig weld it and call it a day but
the smallest of tee tinny seepage will stink like
hell in your garage and it will remind you
every time you get near you car.

Gordon0652

iTrader: (4)

Believe it or not, you can weld on a gas tank with the gas in it it might sound crazy, but you can. If you use a MIG, TIG, or an ARC you can weld with gas in the tank. Think about it, what do you need for a fire? You need a fuel (ex. Gas, Wood, anything that burns) and you need oxygen! If you have total absence of oxygen, there can't be a fire, even if there are fumes around, or a fuel, still can't be. To have total absence of oxygen purge the gas tank (fill the gas tank) with an inert gas (ex. C02, Argon, welding gases) All of these gases will not substain a flame. You have the fuel (gas), but you dont have the oxygen, so nothing will happen, but you will have a deeper, and better weld, and weld apperence.

Warning: This does not work with nitromethane.

383ysi

I made my tank into a sump. Pulled my truck in and put a 2"in hose on the exhaust and routed it into the tank. Waited till the tank got warm, left the truck running and mig welded fine. The exhaust gas sufficated it so it wouldn't ignite.

Ping King

iTrader: (20)

i pulled my tank out, wiped all the gas out..then filled it with water a few times. After all welding was done i put fuel tank sealer in.

Ping King

iTrader: (20)

and it wont work when you burn a hole through the tank and soak yourself in gasoline lol

Gordon0652

iTrader: (4)

The gasoline should be on the opposite side, so the inert gas is underneath the weld, and the gasoline is underneath the inert gas.

WELD / INERT GAS / GASOLINE

TTAWD

I've done this before it works well.

383hatch

I did my tank like you do a oil pan for a supercharger. I took and used a big punch that tapers to a point, and tapped it into the tank. After all the gas drained out, we kept pushing the punch it until it was about big enough for the right size fitting. We then greased up a tap really good to catch any shavings, and made threads in the tank. Then screwed in the fitting and put some gorilla snot around the the area, and its leak free!