Gas tank welding
 

Since I'm doing the usual "winter" redo on my Nomad... one of the projects is to make my Stainless Steel fuel tank a little narrower... and to add a sump (this Rock Valley tank was originally designed for when I had a carb)...

I found this information about "safe" welding on a gas tank and thought that it is not only informative - but simple and easy.


In order to weld a gasoline fuel tank safely, first remove all traces of fuel. Before welding, wash out your fuel tank with warm soapy water, then rinse with clear water. This should remove fuel residue.

Next, you'll need to remove all traces of flammable gasoline fumes. To remove the fumes from the gas tank, insert small pieces or pellets of dry ice into the filler neck of the tank. As the dry ice comes in contact with air, it will sublimate directly into carbon dioxide gas, which is the fog effect dry ice is known to produce.

Dry ice produces no liquid but rather sublimates from solid to gas. Because CO2 gas is heavier than oxygen, it displaces, or pushes out oxygen from the fuel tank. The fumes will be pushed out of the tank and without oxygen present, the risk for fire or explosion when welding can be eliminated if done properly using this dry ice technique.

If I was you, I'd skip all those steps and just start cutting and welding. :thumbsup::rofl:

Thanks for the info, I've welded on only one or two tanks and filled them with water up to where I welded. Funny thing was, nobody wanted to stay in the shop while I welded on it. I've seen the dry ice done on gas station fuel tanks where they cut and welded in a hatch big enough for a man to enter and coat the tank with sealer to comply with new regulations. The welder is still alive, so I guess it works! :thumbsup:

Sooner or later, I'll need to weld on one, so it's good to hear about from other sources.

I think I'd stick a shop air hose in the tank, use a brass valve set on low flow for a couple of hours before washing out to dry the fuel out better.

Hey, once I had a pickup truck tank that was dented in on the bottom. I put a good 100 feet of air hose from a control valve over to the tank, pumped air into the tank until the dent popped out and released it! :thumbsup: I"ve done two tanks that way, but no one hung around for that one either! :willy:
David

I welded my Chevelle gas tank once, I put the garden hose into it and went for lunch, emptied it and welded (outside the garage) I was a nervewreck tho :o)

Sounds like conspiracy!?!?,.......:_paranoid

Todd my stomach hurts :lol: :rofl:

I'm certainly no expert welder, but the story my welding instructor told me onc about the tank that blew up and knocked him backwards, has me convinced I'll just buy a new tank, rather than ever weld an existing one.

And this was after "taking precautions".

:rofl: :rofl: Hahahahaha!!! Gee, with friends like this, who needs enemies, huh?? They always said, "Keep your enemies close and your friends closer." Ahh, I know you guys are just fooling around. Good laugh though.:thumbsup:

you can skip most of those steps by doing a few other things.

Drain the tank first. Then fill the tank with any inert gas. No need to remove all traces of fuel if there isn't any oxygen to go with the flame.

Argon, mig gas, even exhaust fumes will work.

I got a good chuckle as I was writing that one too. I remember Tyler and Russ down at ATS using dish soap and a garden hose and letting it flow for like 10 minutes.

In all seriousness, with you money, pay somebody. :unibrow:

Todd!

Where's the 'hot rodder' in that? Hell - anybody can pay someone else to do their work... but there's no pride in that... no "I did X"

Besides -- you look a guy in the eye and tell him you cut and welded your gas tank -- that dude thinks you're a crazy guy! He won't mess with you - ever!

:rofl:

Good info Greg

Besides if things go in the wrong direction you can always to cover in the pool, thats if you filled it yet which I doubt.

LOL --- That's good info right there! Hadn't thought about welding poolside!

Yes it has water in it year 'round... and the pool boy comes once a week 52 weeks a year...

I have multiple tanks of welding gasses (with TIG and MIG machines - and Stainless gas mix for SS MIG welding) -- so will run some gas through the tank while cutting and welding --- but posted the Dry Ice "fix" because most guys DON'T have access to multi tanks of gas etc... and I'd never seen that solution before. That came off a dry ice supply website - not a "forum" so I know it's good info.

http://www.continentalcarbonic.com/d...th-dry-ice.php

Says you can use dry ice to get rid of bed bugs too! Won't be needing that here - but ya never know where ya might wind up some time! :rofl:

I hear ya, if I was a rich guy I'd have to much pride to pass the buck in most situations. This might be one of those deals. :unibrow:

I once put on a wet suit and welded a gas tank in my swiming pool.:lol: :lol:

Just be sure to make contact with the lead and the ground - one in each hand...

LOL

I work in the Industrial Gas business. If you put your tig gas (argon) in the gas tank you will have a 50/50 mix of argon/fuel vapor. If you purge it again you will have a 60/40 mix and so on. Dryice CO2, when it turns form solid to gas it builds psi, giving you a continuous purge. Let it sit in there for at least an hour. Please don't use any other "welding gases" you would use 200+ feet before it would be safe and even then?

I ran about a gallon of SIMPLE GREEN straight from the jug in the tank yesterday... flipped it - swished it - end for end etc.... then flushed it with cold water. Then filled it 3/4's full - and added the rest of the gallon jug of Simple Green to that - and agitated the tank after filling it.... Then drained it and rinsed it again a couple times. It's now drying in the shop. I'll give it a couple days to dry out.

I'm going to do the dry ice bit - I like that idea.. it makes sense to me - and is easy to do and to get at the grocery store. Besides - I can play with it and make fog and stuff... :rofl:

Normally - if I'm welding SS tubing etc -- I'll back gas it... but that is for looks and cleanliness (different type of welding). When I said "welding gases" I'm talking INERT gases - CO2 or ARGON or CO2/ARGON mix... any of which will/would work fine for this since they're INERT...

Man you guys should build the space Shuttle with all these hypothiths.

I've welded about 8 gas tanks over the last few years. The secret issssss ? drum roll please...... Take liquid dawn hand soap. Put it in a bucket mix it real good and poor it in the tank. Swish it around a few times let it sit on one side for an 1/2 hr. or more turn it over and do the same. Flush it out with water. Blow it out dry it off and weld. That simple!! And just think you eat off this stuff. It also has a good smell. :woot:

Mark

but....but....but....

It's so much fun to discuss... and engineer... and think about... and research...

:rofl:


I have to tell ya -- part of this - is the SNIFF TEST.... you clean out the tank - and let it dry... stick your schnoz in there and inhale... if it smells like gas... you'd best clean it again.

That's why I used the SIMPLE GREEN.... its a detergent... water and gas don't mix..... so flushing with just water - is not going to get the gas out... you've got to add some detergent. Just the same - I'll still back gas or dry ice the tank - just because "I'll feel better" about it... to me - it's like "why not"?

I'm a licensed (Internationally) pyro... anything that goes boom --- "I" want to have control over - I say who - I say when.... (A line from Pretty Woman). :rofl:

THANK YOU MARK (for the soap info) - that does make me feel better.... and I'm relatively certain I'm on the right track.

I going to use the wet suit & try a wading pool next time.So only my feet get wet.:lol: :lol:

I'm not too far from Greg. If I feel my house move and see a large plume of smoke to the south I will let you all know.:D

Nah --- I got me a whole new plan cookin' !!

I'm takin' it down to TODDS...

:rofl:

Just what the world needs---if only there were more like you out there :lol:

Doug

Yeah Doug -- You can just feel the love huh?!


:rofl:

Todd doesn't even want me to empty the tank - just start cuttin' and weldin'...

Well, I'm appalled--- coming from someone as sensative and caring as Todd--that's a real shock.

Doug

Greg, what's the problem. Can't you just light a match,that will take care of the fumes wont it.Then you should be able to start welding as much as you want to.:lol: :rofl:

Todds not stupid, hes going to dump the gas in his mower and save a couple of bucks

Guessing- fill the tank with inert non flam. gas and under slight pressure hes going to weld away. No oxygen, No Boom. Just make sure its purged of air. High school auto 101

My ears were burning out in the garage.....:unibrow:

Dah, Maybe I should backtrack posts once and awhile. This method was mentioned prior. Next.

It's okay - we've all done that... Me, probably more than a few times!:rofl:

The real debate is all about Todd just wanting me to suck it up and weld away - skip all that cleaning and back gas bs.... Says the eyebrows will grow back in no time.

I was thinking that I have a few squibs laying around here somewhere... since I'm a pyro (retired) and I could take Coolwelders advice and just light 'er up... and once the smoke clears (and the fire department gives me the all clear) - I can weld on it, no problem -- all the gas and fumes should be gone.

I've been talking to Gwen about it though - and she's warming up to do the job this weekend - you know - while I'm away....


Thought I'd better make an into to what a squib is... sorry -- pyro lingo...


Squib (explosive):

A squib is a miniature explosive device used in a wide range of industries, from special effects to military applications. They resemble tiny sticks of dynamite, both in appearance and construction, although with considerably less explosive power. Squibs can be used to generate mechanical force, as well as to provide pyrotechnic effects for both film and live theatrics. Squibs can be used for shattering or propelling a variety of materials.[1]
A squib generally consists of a small tube filled with an explosive substance, with a detonator running through the length of its core, similar to a stick of dynamite. Also similar to dynamite, the detonator can be a slow-burning fuse, or as is more common today, a wire connected to a remote electronic trigger.[2] Squibs range in size, anywhere from 2 to 15 millimeters in diameter.[1]
Squibs are sometimes confused with electric matches, as well as with detonators. While those are specifically used to trigger larger explosions, squibs are generally (but not always) the main explosive element.[1]

Yes the "welding gases" are inert, but they mix. Like 75 argon 25 co2. How do you get both gases out the end of your mig gun? They mix. The problem with the gas tank is you do not know how much Argon it will take to be 100% none flammable. Dryice is the heavest of the inert gases and there is 100 times more gas in dryice vs a bottle of argon. So drop a bunch of peices in let it gases off. Don't guess with "welding gases"

Dry ice it is....

It's cheap - simple and watching the fog it makes will be kool... :rofl:

Shoot some video of the process... would be cool to see.

What the minature mushroom cloud.:rofl:

I'm kind of planning on using this to clear out any remaining fumes or excess gas. My plan is to do this in Todds front yard... it should be 'ok'...

what to do with the extra dry ice.
 

after your done welding the tank and your eybrows grow back. take the some of the dry ice and fill a 20 oz bottle about 1/2 full of water then take a small hand full of ice chunks and put the in the bottle and twist the cap on tight make shure you are outside and you can toss the bottle away from you and wait you will be amazed at how much power it has.and how loud it is:wow: just don't bring you wife out to see it she won't be quite as impressed when the cap wizzes by her head trust me on this one. lol.:lol:

:lol: :lol:

Eric -- I'm certain on the "wife" part!

Real men though -- play with bigger toys than that!

Here's a 50" inch shell being built at a munitions factory in Inchon, Korea... I am not "Mister Chin" in the photo... I'm the "other guy"... :>)

Thats one heck of a shell there. Todd could fit inside of that.