[amodoko]

Hey guys, completely new to welding here. I just bought a very cheap MIG 100 Welder with flux core wire to kind of get me started. And the first thing I have to do is weld the underside of my Dad's self-propelled lawn mower for him. A metal bar on the underside that controls height needs to be welded since it keeps separating.

The lawn mower has gas in the tank and the tank is plastic. I will have to tilt the mower on its side to do the welding since I'm welding the underside of the mower deck. I looked up safety stuff about welding near gasoline and two ideas came up quite a bit but I wanted to double check the safety of them first with others here.

1) Fill the gas tank up all the way to the top. Close the lid. Cover the tank with a wet towel. Then weld.

2) Just shield the tank from sparks/etc by using a metal barrier (however I will kind of be shielded anyways since the tank is on the opposite side of the mower deck, so the mower deck will be acting as my shield).

The problem is when I will be welding, the mower will have to be on its side, so gasoline will probably drip a bit from the tank on the opposite side from where I will be welding. I will be protected in some sense from the mower deck since the welding will be under the deck, and the tank is on the other side of the deck. Maybe I can fix any gasoline leaking from the tank when it is on its side by using some teflon tape for a tighter seal around the tank. I'm not really worried about anything touching the dripping gasoline since the welding and sparks will have a very difficult time reaching that area due to the mower deck being in the way, but I'm more worried about fumes. I am doing this outside, so there will be plenty of ventilation.

But with the setup and conditions described, are any of these methods safe to do? I'll probably just do number 1 if that is considered safe. I'll only need about 30 seconds to do the welding, but want to be safe.

Thanks in advance for any help

 

[oh'mike]

Drain out all the fuel and let the tank dry out.

Do not tip the mower with fuel in the tank--then don a black out mask and start welding---just to risky---

I got some very serious burns from gasoline---I would not wish that on anyone--Be careful.-Mike--

 

[amodoko]

Okay thanks for the advice! I will do just that then. I'll drain out all the gas from the tank, leave the gas cap off, and let it dry over a day or so.

When I go to weld once all the gas is drained from the tank, I'll tip the mower over, but should I still keep the gas cap off of the tank in case there are any fumes inside the tank (to prevent pressurized vapors)?

Thanks a bunch

 

[de-nagorg]

I would go a step further , After the tank is empty and dried out, I would remove it from the mower, it is held on by 2 screws and a hose, remove it take it to the other side of the yard, then tip it up and weld the thing together, let it cool and reassemble it.

As a side note liquid gasoline will not burn, it's the vapors from gasoline that is explosive.

Remove the tank and store it away from your work area.


ED

 

[Colbyt]

What he said!

There is enough vapor in an empty tank to explode.

Be save don't become an IED.

 

[amodoko]

Sorry for the late reply guys, I'm having some issues with my account where I'm not always notified of a reply so I didn't know if there were any until I checked today. But I appreciate the advice, and will do as said. I'll remove the tank completely after it has been drained. That's some great advice!