Need tips for welding a gas tank

[Egon]

Is the op going to be welding underwater???

 

[The Haymaker]

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


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

Why are you trying to weld the gas tank underwater? Man, talk about doing things the hard way. All you have to do is FILL the tank with water, leaving enough airspace to provide a air pocket at the weld site.

Unless you were anxious to put on your dive gear and have already tied blocks to the tank and heaved it into the deep end at the "Y", our way is easier. :confused2::confused2::confused2:

 

[Cat_Driver]

My advice, take it to a pro and pay the $80.00 or so to have it done.
My buddy burnt his house down welding a fuel tank.

He emptied the gas alright and filled it with water, but the fumes from the container traveled along the floor, hit the torch and buh bye house and garage.

He and the family were ok but the house and garage, not so much.

 

[rhett]

Is the op going to be welding underwater???

I guess the point is not getting across.
Putting water in the vessel, water is on the inside not out. No need for dive gear.
The hazard is still there, water inside or out. Underwater welding is a reference with more information to be had on the subject.

Another note: welds that are quickly quenched (cooled) are brittle and cracks develop quickly.

Go ahead take the advice at your risk, might even make news at 6.

Cat_Driver gives good advice, if you have to ask how to, his should be followed.

Now I am on my way to jump in the deep end of the "Y", cheers

 

[Mark @ Everlast]

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

I have made a few of those. I built a large one for a guy who used it on his diesel truck. Boy would that thing put out. He said it helped out 3-5 mpg. When he flipped it on, the rpm would jump. I figured it would be a wash though because of the alternator draw. He claimed it wasn't.

I have often wondered why they couldn't build a solar powered car that could be used to separate water into HOO, that could be collected to run an internal combustion engine? Anyone see a problem with this?

 

[Artisan]

I lived in Bullhead City Arizona from like 13 to 15 years old. (Currently 53) Dad used to let me take the Chevy 2 Nova and go party. There was a long dirt road about 80 to 100 feet wide and we would get going about 80 and throw that baby into spins and throw on the e-barke and do everything under the sun going insane at spped and you name it. One day I smelled gas, it was the gas tank leaking! OH NO! A rock blew a hole in the bottom of the tank! BeauJack Welding was on that big ol' dirt road. I pulled in, he told me to go fill it up w/ gas and come back. I went back and he welded it up... HA! I remember stepping wayyyyy back.

This was all good till one day Dad called me out to the car, he had the hood open, he pointed to the intake manifold and asked me if I knew how all those rocks and stones and pebbles and dirt accumulated up there...

BUSTED!

I learned how to handle an out of control car. I recommend it for all young men. I would suggest a controlled enviroment though...:laughing:

 

[muddstopper]

I dont think some peope can read or there is way to much information provided and it is confusing everybody. The suggestion to pay someone $80 to weld the tank when I have already posted I can buy a new one for $46 was ridiculous. No Offense, but did you read the entire thread or just miss the part about the cost of a new tank. I also never said I was going to weld the tank under water, where did this come from. In fact I said the tank would be full of water except for about an inch below the top of the filler neck that protrudes several inches above the tank. There will be no welding in water and any moisture present in the weld would be whatever moisture is contained already in the welding rod. Maybe I need to take some pic of the tank to better show what I am wanting to do. Basicly I just need to weld a short nipple to the top end of the filler neck to accept a vented gas cap. Water level would be just below the nipple and tank would be completely full. Any hydrogen created should easily dissipate to the atmosphere since there really isnt any place for it to accumilate or create a pocket. Its a 2in nipplel about 2 inches long, with one end completely open, just how much gas or hydrogen fumes can accumilate in that amount of space.

I dont consider myself an expert and think I made evident my desire to do this as safely as possible or not at all. I also have been around a long time and realize the danger presented with welding on a gas tank. The fact that I have already looked at other options, buying a new tank or building a new tank, should suggest that I am not at all comfortable welding on that tank. Still I think flushing this particular tank and then filling with water should eliminate any possible flash potential. I say this because the tank design is a square, welded steel that can be completely filled with water to eliminate all void or possible air pockets that could hold the explosive vapors. Filler neck is on the top of the tank and not on the side. Now, if this tank was one of those stamped steel tanks and the hole was in the bottom, or I could not completely fill the tank with water, I probably wouldnt even consider sticking a torch to it

 

[deereman75]

Well this is coming from someone who has never welded any kind of tank, but personally I would just fill it with water, and get welding. The little space not full of water is so small, that even if it had the perfect air to fuel mixture, the resulting boom wouldnt do anything other then maybe scare you a bit.

 

[boomer1025]

I dont think some peope can read or there is way to much information provided and it is confusing everybody. The suggestion to pay someone $80 to weld the tank when I have already posted I can buy a new one for $46 was ridiculous. No Offense, but did you read the entire thread or just miss the part about the cost of a new tank. I also never said I was going to weld the tank under water, where did this come from. In fact I said the tank would be full of water except for about an inch below the top of the filler neck that protrudes several inches above the tank. There will be no welding in water and any moisture present in the weld would be whatever moisture is contained already in the welding rod. Maybe I need to take some pic of the tank to better show what I am wanting to do. Basicly I just need to weld a short nipple to the top end of the filler neck to accept a vented gas cap. Water level would be just below the nipple and tank would be completely full. Any hydrogen created should easily dissipate to the atmosphere since there really isnt any place for it to accumilate or create a pocket. Its a 2in nipplel about 2 inches long, with one end completely open, just how much gas or hydrogen fumes can accumilate in that amount of space.

I dont consider myself an expert and think I made evident my desire to do this as safely as possible or not at all. I also have been around a long time and realize the danger presented with welding on a gas tank. The fact that I have already looked at other options, buying a new tank or building a new tank, should suggest that I am not at all comfortable welding on that tank. Still I think flushing this particular tank and then filling with water should eliminate any possible flash potential. I say this because the tank design is a square, welded steel that can be completely filled with water to eliminate all void or possible air pockets that could hold the explosive vapors. Filler neck is on the top of the tank and not on the side. Now, if this tank was one of those stamped steel tanks and the hole was in the bottom, or I could not completely fill the tank with water, I probably wouldnt even consider sticking a torch to it

So, you going to buy one from Walmart or weld the nipple on ??

 

[Mounted Madness]

A couple of bikes ago, I'd ridden the bike from home to my uncles farm. Enroute to the farm, a couple of pinhole leaks developed on the low side of the tank. No doubt caused by sitting with water at the lowest part of the tank, through several winters.

Believe me, a leak is one thing, but discovering it at speed on the highway, while smoking was sphinkter motivating to say the least.

Anyway, once at the farm, we pulled the tank off the bike, removed the remaining fuel and then to make sure the tank was purged of fumes, ran exhaust fumes from his truck into the tank for about 5 minutes. Then ground off the paint down to bare metal.

Following that, he lit up the torch to braze the existing holes and new holes found during the grinding. To prove to me that there were no gasoline fumes in the tank, he passed the torch around and into the tank without incident or fuss. Brazing done, a coat of primer, and tank back on the bike, the bike was sold 2 years later without any notice of the brazing, and no leaks. :thumbsup: