If you're using CO2 shielding gas why not inert the space above the petrol in the tank & then secure the lid (if necessary tape off vent holes in lid) to keep the CO2 in.
Occasionally at work we were called onto explosive test prior to welding leaks on Sentinel type railway shunter diesel tanks. We used N2 from bottles but CO2 is just as inert.
RonA
We used to have a special inert gas generator machine (nicknamed Stephenson rocket) that worked by burning diesel. We abandoned the practice once we had piped N2 on site as it provides a reliable totally inert atmosphere whereas we still had about 1% O2 using the inserts machine. However, I gather they still use the waste gases for inserting on things like oil tankers at sea.Due to the small size weight i would just remove tank and or engine.
Totally agree did one in April just that it didn't say what sort of mowerSee post 2.
Seriously, it takes under a minute to take the engine (with attached fuel tank) off.
3 bloody bolts - "nah mate, be quicker to take it to the moon where there's no air and weld it there"
a lot of over thinking projects use the kis rule keep it simple
as long as your happy that's all that counts no big dealI was welding close to my petrol tank today. I know it doesn't leak, the vent and fuel hoses were blocked and then the tank was purged with CO2,
View attachment 114548
now I'll wait for the replies to say how reckless I am.