Weld's spitting and spluttering

[clinton walker]

Hi im just wondering if someone could help me with some advice,ive done some mig welding but not alot but im in the process of welding up my ford transit rear floor and some of the chassis and it's going quite well,i find when im welding the new tin to the old floor is ok and when i join the new tin together it goes well, but some area's underneath on the chassis it just spits and splutters ive cleaned the metal up as good as i can,these area are annoying me as most of the welds look fairly good and these area's are even to hard to get to with a grinder to neaten up.Is it because it isn't clean enough or is there something in the original metal thats causing this problem thanks in advance.

 

[shenion]

If the metal is galvanized it will make a real mess. It needs to be ground off.

Also, be careful, the fumes can cause a nasty reaction.

 

[hotrodder]

I don't know my transits but if you were struggling to get access to clean coatings/underseal etc then that'd be where my money is. Any anti corrosion coatings would be more akin to zintec than galvanised i would think (still not pleasent to breath but a different animal re. weldability. What about the work clamp? Poor connection there maybe?