Don't wanda go boom !! - gas tank repair

While removing my gas tank to repair the sending unit, I did a big "Oh &^*%" when loosening the fuel line. The fitting that the pick up is on twisted slightly on the tank - I'm sure the seal will be broken.

What is the best way to ensure its safe to braze the fitting back in place without worrying about going 50 feet in the air ???

Thank much - best of the season to all !!!!

 

take it to an expert ! i know too many friends that have had close calls filling them and trying to weld on them, its not worth your life spend a few bucks and let an expert handle it !

 

When we do any welding on a fuel tank, we wash it inside and out with a powerfull detergent degreaser and water mix . I use ZEP purple cleaner which is pretty similar to Castrol Power Clean.


Once rinsed out I will use compressed air to dry it out for about 10 minutes. Then I hook up an extra Argon bottle and regulator with a 1/4 plastic line into the fuel feed fitting and loosly fit the gas cap or at least stuff a rag lightly into the fillneck. Let that sit for about five minutes or so with the argon flowing and then I do my work.

Pain in the ****, but I have never even had a slight mishap.

 

Don't know if this will help you due to tank your location/ size.

What we always did with motorcycle tanks that needed welding was to empty the tank, pull the fuel pet**** off the bottom, crank up your car or truck and direct the exhaust gases into the tank filler. Let the car run until the tank was good and warm from the exhaust. The exhaust gases & heat dry up any residual liquid and flush out the explosive fumes.

We always gave it the sniff test, shouldn't be able to smell any hint of gasoline. We also gave it the "hide behind something and flash the torch over the gas opening" test. If it had been done correctly, nary a ****.

Anyway, be careful, good luck and Merry Christmas!

 

Put dry ice inside or the exhaust method.

 

ditto on the dry ice

 

If you check closely you may have a soldered joint. If so just use a good hot solder iron. No flame, No spark, No Ka-Boom
The Wizzard

 

Many times I've repaired small Puncture holes with a Piece of Copper and solder. Never had a problem with them after.
The Wizzard

 

you will never get it all out. no matter how much time or washing you do. ASK ME HOW I KNOW

YES, filling it with inert gas will make it safer. But isn't it even safer to take it to someone who knows what they are doing?

I'm with the guys that said take it to a pro!

 

i dont know if you have enough room but i have put a penny on a hole in a tank that was drilled and heated up a large solid rod cherry red and put flux on the penny and used the heat from the rod to melt the penny into the tank

 

After reading countless explosion stories in these posts, I would say that the best person to do the repair is ANYONE but yourself. Take it to a pro who will most likely not blow up, and if they do, you still have your hands and eyebrows. D.

 

My buddy is a certified welder and machinist and volunter fireman , runs a first rate machine and welding shop and has welded on dozens of fuel tanks , he always runs the exhaust from a small engine into the tank to replace the oxygen with carbon monoxide, He swears by it and says he has never had a accidental explosion or fire. Hell, he even welds on them with fuel in the tanks, He says it has to do with the fire triangle , you have to have fuel , air and a souce of combustion or heat , take away any of those and no boom. But , I need to add , I totally agree with the rest of the posts , TAKE IT TO AN EXPERT!!!!, as they say don't try this at home ,,,,,

 

fill the tank with water.

leave the gas cap off, sending unit out.

 

we welded the fuel tank on our funny car after washing it out ith everything we had and it still blew up it was the loudest noise ever i couldnt hear for a day but neway after that we would flush them with exhaust fumes from the tow vehickle and never had another problem

 

if you can find someone who does tank repairs, they can steam clean out all the varnish. the varnish heats up from the heat,and gives off explosive fumes. if it's cleaned right by an expert, the steam cleaning takes off the varnish down to bare steel. if you do this,when you get done, look at eastwood.com and get one of their tank sealer kits. lots of times if you clean a tank that well, it will start leaking from pinholes that were sealed by old tank varnish,the sealer kit fixes this and gives you a nice clean tank inside.

 

the heat is the problem, when you heat it up, the tank varnish vaporizes back into explosive fumes, then one s****e of a tool or something on the tank,or a little bit of static, and BOOM!! the argon idea is a pretty good one,if you displace the oxygen with a positive pressure from an inert gas, in theory it shouldn't blow up. IN THEORY

 

id fill it with water than weld , or drain it wash it out with water, then lite it with a match if the caps off and the sending units out it wont blow up just make a cool torch, may have to light it a few time blowing air into it each time, gas only burns fast, it will only blow up a thing if its sealed and the burnt vapor cannot escape as fast as it expands, i grew up in a junk yard so did my dad, his dad stared street and sons in 1933 and none of us have ever seen a blown up gas tank, maybe a split from the preasure of expansion or the cap blows off, in the past weve got cars with gas tanks lookin like swiss cheese from people shootin them with copper bullets

 

oh empty gas tanks are more dangours cause the vapor burns faster then the liquid will

 

You have to steam out and/or inert gas blanket the tank. Steaming takes the fuel away; interting takes the O2 away. Both steam and intert blanket are best. N2, CO2 (dry ice), engine exhaust, are examples of inert gases. I agree with the consensus; take it to an expert who does this kind of thing routinely if you are not fully familiar with what you're doing.

 

If the pickup will come out, I would drill and tap the hole in the tank up to next NPT bushing/reducer.

 

JB weld? We use it alot in Wyoming.

 

When you set up your Tig (Heliarc) to weld it, you put an Argon purge on it.

Makes everything weld out real nice with no explosions and no sugar on the inside surfaces.

How the pros would do it. K

 

I drained my tank left the lid off for a week .Then I washed it out with soapy water .After all of that I put the torch flame in the tank .I would rather have it flame up when I was expecting it no flame or explosion .This worked for me I have used this method 3 times


I also needed to tell you I built my tanks out of stainless .I had to modify this last one in my coupe so the roll cage would fit. My 2 cents

 

take it to someone who knows what they are doing..I'm all about trying to do something yourself..but this isnt something to experiment with. Just my 0.02

 

if you have it cleaned properly by someone who actually knows what they are doing,you will be fine. it's the varnish thats hard to get out. you can clean it all day with soapy water,it won't touch that varnish thats coating everything in there. the varnish vaporizes under heat,thats what always gets everyone. eastwood also sells a kit that mixes with acetone and muratic acid i believe, it's supposed to disolve all that.it comes with a chain,you put the chemicals and chain in there, and slosh it around. the chemicals eat and disolve the varnish.

 

25 replys and I'll be only the second one to suggest the simplest, easyest way. Electric solder iron, acid flux, solder. 10 minutes, done.

 

If it was my tank , I would drain all the gas out and let a pro do it . I have read about to many hotrodders loosing their car , garage and sometimes their life due to gas and an open flame ! If you do it yourself , take it outside away from anything else that can go BOOM . Just be safe and tell us all that it is fixed with no problems ! Be careful !

 

if you are going to go to the trouble of removing it, have it cleaned by a pro, fix it, seal it,then when you put it back on you will have a nice clean tank inside,you will be amazed how much garbage comes out when it's cleaned. this will give you a good basis for a trouble free fuel system later.

 

one more opinion - compressed fumes are what explodes, so do not fill with water or anything other than air. I have been repairing fuel tanks for years. But the first time you think you know it all is the last time you fix one !! I remove any and all fittings, senders, fill necks, drain plug or what ever will come off and leave an opening. Then after ***uring myself that it's empty I put an open air hose shooting air from my compressor into the tank. with the compressed air going AT ALL AT TIMES while I'm welding there is next to no chance for the fumes to get trapped and expode. leave the air hose in the tank for a few minutes after the welding is done and you reduce the chance of warpage.
Howevcer as has been previously mentioned you probably have a soildered connection and low heat and silver soilder will make a good repair.

 

10-4 And you probably won't even half to remove it from the Car. Hell, bring it here and I'll do it for you. No Charge!
I've learned it's difficult to teach Rocket Scientist how to tie there Shoes.
The Wizzard