Welding Tips and Tricks

Hi Guys
Just joined and look forward to using this interesting forum.
I am looking for some advice......I am building a mild steel (3mm thicknes) bunded fuel tank (diesel) and was wondering if mig was the best way to go ?? I have no tig welding experience! Our mig gas is a 20% mix (argonsteel 20)...20% co2.....
I here some boys prefer stick welding fuel tanks ?? or flux core welding ??
Its being built indoors (no wind,etc)…please throw some idea's at me if you get a chance. Cheers

Welcome to the forum justynjspuk.

Mig is fine for welding tanks & would be the most logical choice in steel as it is suited to seam runs without putting in excessive heat & causing undue warping ( Tig is OK for little tiny ones or stainless but usually quite unnecessary ) - sure others will pitch in but my 2cents is obviously do some test joints & get the settings dialed in on some off cuts of the same thickness - try to cut all your material to provide open corner welds so you are filling in the corners full thickness - it's easy to get cold laps with Mig so feather all your starts & over run all your stops - where possible do all your tacks on the inside leaving the open corner joints as clean runs - cut an outlet or inspection port or one of the intended fitting holes in early on so as the interior air volume increases with heat build up it can escape without being forced through the weld joints causing shielding problems - I prefer to drop to a small wire size with plenty of power rather than trying to run a larger wire on the lower end - when your done welding I like to put a few PSI of air pressure in & check all welds with soapy water - if all seems good then fill it with water & leave several hours with it's full intended weight of liquid in - if all is well then paint - nothing worse than finding pin hole porosity or cold lap after the fact & have to go back for a redo - especially once it's had fuel in - I imagine I forgot something that others will point out - good luck with your project.

mig is fine if done properly.

if its a mobile tank, then imho the design is a much bigger issue. baffles, bracing and mounting points are important.

Thanks a lot guys for the info. I'll give it a good go with the mig...0.8 wire , with baffles, strengthening etc, I might cross press some of the panels for extra strength .Some good tips from you , many thanks ! Happy xmas and new year !!