How can I safely weld a pair of brackets onto the boat gas tank that i'm useing in my 50 plymouth? The metal is thicker than stamped automotive tanks. I was thinking maybe, drain gas, fill with water and arc weld with high heat to counter act the cooling effect the water will have. The water will displace the gas fumes. Will this work?? Any other ideas???
the only thin i know is ,if you have a fire with gas or oil never extinguish ( wow what a translate program can do with water ???
Yes, alot of guys will fill them with water to weld them. It is safe and the water acts like a heatsink to prevent burn through, You can also just run high pressure air through the tank during welding. It will displace the fumes. Its the fumes that go bang not the liquid.
My brother says, I need to start a car and run exhaust fumes through the tank to displace the fumes and then weld. Anybody ever try this???
I welded up a filler hose on a tank once just pulled the tank, laid it such an angle as to completely fill with water and brazed it on where it was pulling out, I'm still here so it must have worked a high heat might blow holes in it, just make sure the tank is full of water but make sure you don't electicute yourself if you do and your rod hits the water I was always told an empty gas tank is explosive where a full one will only burn
yes ... I have a cousin who does this all the time ..... just wait until the tank is WARM to the touch ..... he's done LOTS of 'em and he's still here ...... And I usually "silver solder" on my tanks .... NO burn thru like welding and ya can actually "puddle" the solder to fill in a crack.....use the correct flux .... Jersey Skip
That's what ya' want to do. I think the CO is heavier and purges/displaces the air/fumes in the tank. When I was in a maintenance unit in the US Army there was a FM (Field Manual) that recommended using this procedure before during any fuel tank repair.
I take mine to the car wash, run the soap water to clean them out. Take them home, run the air hose from the compressor ( set at about 5 lb.) into it. Leave it set for an 1/2 hr. than sloder them up, while the air is running through the tank. I don't know how welding is going to work for you, tanks are thin.
The tank is real heavy gauge steel. Not your average automotive stuff. THANKS TO ALL...WISH ME GOOD LUCK..
I take them to the carwash,fill it with Tide and soapy water for awhile then rinse well. Take it home and let it drain and dry for a night . Take it out back of the garage and make a rope out of twisted up newspapers about 3 feet long .Half of it in the tank ,light the other end and run .After the lit end falls in ,if it doesn't blow up I weld it. ( I have never had one blow up)
Get it purged at a tank shop is your best bet! Forget filling with water...it concentrates the fumes into any hidden air pockets. Hit one...go BOOM! Watched it happen to a guy. (He was lucky thank god!) The exhaust purging can work but its still pushing your luck a little bit. I've done it myself but its not the safest way. Not sure about the other ideas. Doing it with water can turn nasty guys...sure its been done...but I SAW it fail.
I filled mine with water, then welded the new fittings and mounts in place using stainless rod and a stick welder. Made damn sure that there was nothing but water on the inside of the tank in the area I was welding. Possibly kind of risky; though you're taking a certain amount of risk anytime you weld on a gas tank, regardless of the method used. And I was lucky as the tank was heavy gauge stainless, so I didn't have to worry about burn through or rusting afterward. Worked well for me.
Welding on any metal container that at one time, no matter how long ago, held flammable fluids, is EXTREMELY dangerous! However, with proper precautions, it can be done in reasonable safety. The air hose idea is extremely dangerous, because all you're doing is providing fresh oxygen to any vapors being created or liberated inside the tank. Do not do this.. Now then, to be dangerous, IE, explosive, the mixture inside the tank needs to be just like that inside a combustion chamber. Too little oxygen and nothing can burn, to little fuel and there's nothing TO burn. Unfortunately, the explosive ratio of gasoline and even diesel/kerosene, is pretty wide. Only at the extremes can it be considered "safe". So, first, we limit the volume of the potential explosive mixture. Fill the tank with water, with just a tiny drop of hand soap to help cut surface tension. However, trying to weld with water on the other side of the material is an exercise in futility. Even if you manage to keep a puddle going, you'll get contamination and porosity of the weld, incomplete penetration, and basically make it so there wasn't any point in doing the weld in the first place. So what you do is make a gas pocket that will give you a bit of room. If you have a MIG or TIG, set up a small hose from your gas bottle regulator, and bubble some Argon or CO2 into the water, and hold the tank so the "bubble" will come to rest behind the area you need to weld. Now, if you've done all that, and kept the bubble relatively small, it should be safe to weld. Do the repair, let the metal cool completely, then drain the tank. I suggest 'rinsing' with some alcohol (HEET) to help remove any water. Let dry throughly, and it should be ready to use. But always keep in mind that literally hundreds of people have been killed by trying to weld on fuel containers. Some tried some 'home brew' measures and died anyway, some didn't even try that. You want to minimize the volume of any potential explosive mixtures (filling with water) since a firecracker, while still dangerous, is still safer than a stick of dynamite. And you need to be sure that, if there's vapors, that you've reduced the oxygen content as much as possible. Preferably zero. Engine exhaust gas is not always free of oxygen, and almost always has traces of it's own combustibles. Use CO2 or argon from a welding setup, it's far more reliable. Also remember that, even after all the above, if you need to weld it again, go through ALL the steps again. Don't skip one because "you just washed it out" with the water last time. Go through the whole process, 'cause that gun can still be loaded. Doc.
Last time I did this I was putting a sump in for a drag car. It cost me $15 and one day to drop it at the local radiator shop to be steamed out. Cheap insurance.
We did mine a couple weeks ago. Took it out of the car, flushed with water. Shot a fire extinguisher in it. The old guy said he"s done a hundred this way. I still stood across the room when he did it.
One presumes a CO2 fire extinguisher. I suspect a dry-chemical extinguisher might not have the effect he was looking for. Doc.
I watched someone weld a bike tank once; he had a car running with pipe into the tank so it filled with exhaust. I stood well back and he made the comment don't look so worried Ive done this heaps of times but it still made me nervous.
DocsMachine is right on the money! I had to weld a sump on an aluminum aircraft tank once. This thing had not had gas in it for probably 40 years. Just to be on the safe side, I rinsed it out with soap and water and let it dry out in the sun. Couldn't be safer right???? Wrong!!!! I hadn't run the bead 1/2 and inch when, WHOMP, something caught and made the tank jump about 4 inches off the table. I jumped so bad I fell backwards off the stool, lucky I didn't crack the floor with my head. Anyway, treat these things like a grenade with the pin pulled, they're just waiting to bite you.
Flush it good with water then purge it with co2. Fire ext works fine. Big thing is skip weld a doubler on first then weld youre brakets to the doubler. That way if youre bracket cracks from vibration it will crack the dblr and not the tank. Just DONT weld the dblr 100% -- skip it. FEDER
My boss is a boat builder by trade ( Tug boats, barges, Oiltankers etc.) When those boats need repairs they generaly need to be made fast, time is money. He has told me stories of welding on tanks with fuel still in them. The trick he tells me is to fill them full of carbon dioxide not exhaust fumes and keep the CO2 flowing while your welding. I'm not a welder by trade so use this method at your own risk!
........when i do a tank here,i remove all plugs senders etc.after flushing with dish soap. i keep flushing untill all soap comes out and all you can smell is the soap, the soap foam pushes all the fumes and gas out.do it at least two times
We've had an aluminum tank in our shop for repairs for at least 3 months that no one wants to mess with. The owner keeps saying to run nitrogen or argon through it while its being welded, but when we tell him to show us he runs into the office. Does it make any difference if its diesel fuel instead of gas?
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