Panel replacement question

[WhoWhatNow]

So I am going to do my first rust repair on my vintage Mercedes 450SL. The panel is the rear passenger side floor directly in front of the fuel tank. I have a new panel to weld in and I think I know how to prep the area and trim the panel. My question is what do people do about the gas tank when welding on a vehicle? I need to be able to pull the car in and out of the shop while I prep the area in case I can’t get everything done in one weekend. The fuel lines run out of the bottom of the tank so it is not too much trouble to drain the tank. Is it enough to drain the tank and reinstall the fuel line to seal it back up or am I going to blow myself up while grinding? I was thinking I could drain the tank, put the lines back then run a fan for a while to get the fumes out of the area. Will this be sufficient?

 

[altersaddle]

I drain the tank and then remove the tank. Not just for safety, but for panel access.

If you haven't done sheet metal repair before, try to get some practice in on scrap before tackling the actual car.

 

[Ohmthis]

Drain the tank then remove it and any fuel lines in close proximity. I don't know the car in question, but you could probably run the engine off a gas can and cheap electric pump to move it.

 

[WhoWhatNow]

I was hoping not to have to drop the tank. The fuel pump is back there too so I guess I should remove that as well.

The car is fuel injected so I am not sure if an electric pump will work.

Looks like I will have to add an extra few hours to the project estimate.

Thanks

 

[EdT]

If the tank is anywhere near where you will be cutting and grinding you really should remove it. You may feel that the risk of hitting it with your grinder or torch is low, and you may be right. To me this is one of those situations where the downside of the risk is so huge that you must remove the tank. The risk is burning up the car, your shop and yourself. The extra couple of hours of work are small compared with the potential loss. I'd remove it.