repairing aluminum gas tank

[ksimpsy]

Hey ive got a tank that has a small pin hole in it and i want to fix it. i have been told that instead of getting the tank steamed i can fill it with water and then weld it. im just wondering if this will work or will i get blowed up. :eek: hah
thanks

[B_C]

Nope, it it will still blow up because you won't be able to weld the pin hole with water behind it...so when you turn the tank so the water goes away from the pin hole you will have an air gap that will burn.....I usually wash them out with soapy water
and then purge with CO2 fire extinguisher.......make sure the gas cap is OFF

[Aerometalworker]

Hey ive got a tank that has a small pin hole in it and i want to fix it. i have been told that instead of getting the tank steamed i can fill it with water and then weld it. im just wondering if this will work or will i get blowed up. :eek: hah
thanks

What kind of tank? What capacity? What type of fuel? Any oil added to the fuel?

Tank welding can be perfectly safe, or something to make headlines in the paper. Having the tank perfectly clean inside will help you in 2 ways. One is to prevent dynamic disassembly of the tank in front of you, the other is making a more sounds weld by eliminating contaminates.

I think for liability reasons....we will only tell you how WE would do it for your particular situation, but in no way are we giving YOU a fool proof method since there are variables to account for where only experience can help you.

Let us know some more details....and we can probably come up with roughly the methods WE would use given the same part.

[Pangea]

~dynamic disassembly ~

I love it! :D

[Aerometalworker]

I love it! :D

You would not believe the way in which we have to word things at work when we have a failure of a test. For liability reasons we cannot use the word "fire" or "explosion" in any written engineering report that involves a failure of a product on test. We have to use "thermal event" and "Rapid uncontrolled thermal event". Why? In case 20 years from now someone has a product of ours fail, due to their fault or ours....our original enginering documents from when the product was developed can be drug into court. Silly huh?

Anyway back to the tank.....still waiting on the details :)

[apache708]

we use to refer to BLEVE as Blast Leveling Everything Very Effectively instead of Boiling Liquid Expanding Vapor Explosion.


or more commonly

Obvious High Stress Heat Induced Tear(I'll let you put the acronym together)

[ksimpsy]

Ok, it is 1/8 aluminum, 6 gallons, regular gasoline no oil. i also do like the "dynamic disassembly" thanks for the help.

[B_C]

Rinse it out with soapy water and let the hose run in the tank for ten minutes leave the cap off and weld it up....
and if it flashes it will let the pressure go out the cap....Done 50 motorcycle tanks that way NO EXPLOSIONS ........

http://www.ytmag.com/articles/artint81.htm

[ksimpsy]

Perfect B_C, if that's works then that's what I'll do. thanks for all the help.

[ksimpsy]

Still alive and the tank is still square. I ended up rinsing it out like B_C said then I threw a air hose in it while I welded it just for a bit of extra reassurance.
Thanks for all the help guys.

[B_C]

I'm Glad it worked for you but in the future I don't think putting and air hose in the tank would be my choice....Because if there was any gas residue (fumes if you like) left in the tank that added Oxygen might create a BOOMING problem for you.....if you have to put something in there to give you more confidence try a CO2 fire extinguisher.....

[Mr Meck]

For next time...For explosions to occur there need be 3 things, Oxygen,Flammable Material, and heat. That is the fire triangle. Remove any one of the three and there be no boomie. I choose to reduce the fuel by cleaning exceptionally well. Then remove the oxygen with argon purge.

[MJL]

I used to work at a trailer shop and we had certified tanker techs there, so we did a lot of tanker trailers. We had a boiler and would run boiling water and steam in the tanks for something like 4 hours, used a sniffer to check for vapors, and had fans to move air and residual vapors out.

Provided it's washed out thoroughly I don't see a problem with blowing air in.

[PPW_Canada]

I worked for a few years in my apprenticeship days in a trailer manufact/repair shop. Fixing fuel tanks was a daily chore with most of the welders. Steaming the tank is ideal. Most back yard welders however don't have a Hotsy steamer at their disposal. I personally ALWAYS opened every opening into the tank and threw an air hose in one of them before striking an arc on the tank or even the mounts or supports. Remember you aren't pumping oxygen into the tank...you are pumping air. The whole reason is to bring any risidual vapors in the tank to below the L.E.L. (Lower Explosive Limit). I would turn on the air hose and let it purge for at least 5 mins, and would leave it run until the repair was finished.

A side note. I have had many people tell me that a diesel tank won't explode. I had pics but can't find them now of a rectangular diesel fuel tank we had from a city bus. We steamed it (but not for very long, maybe 20 mins if i remember), it checked ok with the sniffer, and we did the repair like any other. When the explosion took place it blew one head off the tank and sent it 20 feet away...fortunately no one was hurt.

[autohausfab]

i have a question do you need to use any particular type of aluminum for a fuel cell i have some really nice polished diamond plate 3/16 at work the were throwing away

[mustang0]

If you have the skills to make leak free welds I would have no problem
using that aluminum for a fuel tank. Diamond plate is commonly is made from 3003 which is weldable. A fuel cell though, like for racing will need a filler material and bladder, in which diamond plate will not really be suitable.