Can CO2 cause earth wire to overheat?

[daniel_johno]

Hi all, im new to this forum and have just started trying to weld. I went through 8 disposable bottles of CO2/argon till i realised it was costing to much as i was using 2-3 bottles a day.
I was then advised by a mechanic to get pub gas so i got a big bottle of CO2 for £20 and bought the adaptor and regulator to use on a sealey mightymig100.

I was getting half decent welds when using the argon/co2 gas but now im finding it quite hard to get good welds. It doesnt seem to be penetrating very well if at all and is very splattery although ive read this is a trait of co2.

Something else i am now finding is the welder earth clamp is getting very hot even when on the low setting and is beginning to melt the plastic wire covering. Is this something to do with the co2 as its only been doing this since i started using the CO2.

I am welding a mini so the panels im welding are thin.

Thanks for looking

Daniel

 

[malcolm]

It's unlikely to be the CO2, more likely the more continuous use you get as a result of not changing bottles so often. It's common for cheaper welders to melt the end of their earth wires after prolonged use at max power (they tend to be under-specified), though I'm surprised it happens when bodywork welding.

Maybe the conection between the wire and earth clamp is poor and the high resistance is causing heat build up. You can buy beefier clamps separately - they would earth better than the crocodile clips they provide as standard, and a more consistant earth would make for more consistant welds. Could be worth trying.

 

[daniel_johno]

Ok thanks, ill look into getting a new earth clamp. It seems to start overheating after a few seconds welding.

 

[malcolm]

Few seconds? Then definately high resistance somewhere. That'll be messing up your welding too.

Try a forum search for earth clamps - there will probably be some suppliers mentioned as it's common to upgrade them.

 

[wallopadonkey]

i have not been doing this long but i would check that the part you are grounding to is clean bare metal for starters and is the part you are earthing to close to the point you want to weld ie the shortest possible run from weld pool to earth through the car metal
also make sure where the negative wire is crimped to the crocodile clip is ok not loose and it is all making contact
dave

 

[Archie]

Like Dave says, check the wire itself is properly attached to the clamp. Either the crimping or the bolt (if there is one) could be loose. When mine last came loose I set fire to the bench!