Need tips for welding a gas tank

[Haywire]

Yep, if that were the case, every time you boiled your potatoes on a gas range, the kitchen would explode. It takes electricity to separate the water molecules into hydrogen and oxygen. I fiddled with making a hydrogen booster for the car but figured out that it would be entirely too complicated to regulate the ratios.

Ian

 

[deereman75]

Yep, if that were the case, every time you boiled your potatoes on a gas range, the kitchen would explode. It takes electricity to separate the water molecules into hydrogen and oxygen. I fiddled with making a hydrogen booster for the car but figured out that it would be entirely too complicated to regulate the ratios.

Ian

That reminds me of something I saw on mythbusters one time. I recall it not working too well.

 

[Shield Arc]

What you want to do is remove the oxygen from the tank, while welding. I've done diesel tanks with another diesel engine's exhaust running into the tank. I don't recommend a gas engine exhaust running into the tank. Soapy water right up to the weld zone would be another good way, but I'll stand over here while you do it. :laughing:

 

[boomer1025]

At work we cook diesel/gas tanks several hours with a steam jenny before they get welded.
They make nice roman candles sometimes

 

[rhett]

Pretty sure that doesn't happen..

Ok OK, Arc welding in water Does Produce Hydrogen Gas. My major slip for saying boiling water, I was out of line.

Well, the tank could blowup arc welding it with water in it. A wet arc does produce Hydrogen Gas.

 

[muddstopper]

Ok OK, Arc welding in water Does Produce Hydrogen Gas. My major slip for saying boiling water, I was out of line.

Well, the tank could blowup arc welding it with water in it. A wet arc does produce Hydrogen Gas.

I am going to suspect, but wont claim it as fact, that most hydrogen created while welding probably comes from the moisture absorbed in the welding rod flux and not in the moisture in the atmosphere or a puddle. Still water is water, whether it comes from the rod or for water put purposely in a container. As Myth busters would say, Plausible, altho in this particular situation, not entirely probable. I keep thinking about seeing people welding under water and not seeing any hydrogen explosions.

New Plastic boat tank is $46, (WallyWorld) not including line and fittings. Havent checked out metal prices to just build a new tank, might just go that route instead of refabing the old tank.

 

[yomax4]

A good way to get the gas fumes out is Dawn Dish Soap and Water. Great degreaser too. Fill it up with 10% soap, Balance water and shake it up. let sit overnight, Dump, Rinse. Weld. I've done a pile of Aluminum Fuel Cells and Steel Tractor tanks. Never had a problem. When in doubt, Use the long rod and flaming rag method to calm your fears. :laughing:

 

[muddstopper]

A good way to get the gas fumes out is Dawn Dish Soap and Water. Great degreaser too. Fill it up with 10% soap, Balance water and shake it up. let sit overnight, Dump, Rinse. Weld. I've done a pile of Aluminum Fuel Cells and Steel Tractor tanks. Never had a problem. When in doubt, Use the long rod and flaming rag method to calm your fears. :laughing:

Rod and rag works everytime LOLOLOL

 

[The Haymaker]

Just fill it with water and weld, as many have said. Whatever residual you have, or create, won't be enough to do any real damage if it flashes. Just remember to duct tape your eyebrows.

My Dad always tells the story of how he learned to use water. He was brazing a go-kart tank in his childhood home and found out the hard way that launching a gas tank through your parents bedroom door (And this was years before Sputnik!) at 5am never ended nicely. :laughing:

 

[rhett]

Just fill it with water and weld, as many have said.

Take a look at this link
Underwater Welding Dangers
Second note under "Underwater Welding Dangers"

# Another major risk is an explosion. The formation and combination of hydrogen and oxygen pockets are dangerous because they are explosive and when ignited, they can lead to an underwater explosion.

There is more information about this. People still wonder why or how the tank exploded???