bill r

This new forum is withering on the vine, so here goes: Does anyone know how to be really safe when working with a fuel tank? Does anyone have a fool-proof technique that they have come to rely on? There are so many horror stories; I've never been willing to risk it...

SmithBuilt

What kind of fuel are you referring to?

I have welded on diesel fuel tanks, but I don't know that I would a gas tank.

I have a piece of flexible metal exhaust pipe that I connect to a small engine's exhaust (my generator). Then connect the other end to an opening on the fuel tank or just stick it in the tank where it won't come out. Open another hole in the tank for exhaust to escape. Idle the engine while your welding and the exhaust gas will displace the oxygen in the tank. Run the engine till the weld cools.

If it is a small leak take a punch and hit right where it is leaking, will sometimes work.

bill r

Gas; petroleum in general. Hydraulic tanks, etc. Methinks it all gets volatile when it gets hot. The point is, you've done it and lived to tell about it. I've heard of filling with fuel, filling with water, etc. I can't patch holes with a liquid involved. Your approach is to displace fumes with spent exhaust gas... that's excellent. I guess with a gas tank, you'd need to be careful of the hot exhaust itself...

I would caution the casual reader that this is a very dangerous area and they should be extremely cautious. These are not OSHA sanctioned discussions!

I was raised in Salisbury NC, by the way.

Teetorbilt

We used to fill them with Tide and water to clean and then flood them with an inert gas to weld. You should have Argon on site, Helium is also cheap and readily available.

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skyhook

Dry ice.
www.dryiceinfo.com

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bill r

I guess I'll have to screw up my courage and JUST DO IT. I've heard of dry ice, never tried it. Its hard to find locally. I'll probably try the exhaust gas technique. If I survive, I'll report in. This salt water is eating my barge hydraulic system alive!

Thanks again for the valuable input.

If I can help anyone else, I've done lots of stainless/TIG, lots of hydraulics (all homemade), tons of stick welding. PM if I can ever help.

skyhook

An old timer told me to use dry ice. Some grocery outlets carry a food grade, catering companies use it. I get it from an old ice house, $.99 lb. Keeps in an ice chest for 3 days.

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SmithBuilt

I have heard of using argon. The tank I was welding on was large and I was concerned with flooding the tank with enough argon to make it safe. But felt more comfortable with exhaust gas, plenty of volume.

I'm in Kernersville. Salisbury is a nice area. Both are growing too fast.

I may take you up on the welding advise sometime. I've found a large used mig welder, if I can figure out how to power it I'll have questions.

Mocopperhead

I have used water before. You fill the tank all the way up to just below the point of where you're welding. Leaving a very small bubble exactly where you intend to weld. By all means clean the tank with A LOT of soap an water BEFORE you even start. The exhaust trick works too and is usually less trouble. Hydraulic oil needs to be pre-heated before it will flash so regardless if you use the Water techinque or the Exhaust technique. ALWAYS CLEAN THE TANK FIRST!
I had a buddy of mine who was cutting an old hitch off of a car and burned through the gas tank. Fortunately the gas tank was full and when the gas came out it put his torch out and that's the ONLY thing that kept him from being fried to a crisp.