Posted by Dave Halford on 17/01/2020 21:05:53:
Usual issue with cheap welders – a high-ish minimum current so it might be a hole blower on thin or rusty stuff.
Gasless wire is nearly as messy as stick welding.
Totally agree with the comment on gasless wire, but horses for courses – if you are lying on the drive trying to repair a rusty car the shield gas can disappear with the slightest breeze while a gasless weld, although far more grotty to look at, will have welded OK.
Its what angle grinders were invented for 
The issue with cheap gasless welders is that they are often gasless because you don't pay for a regulator or a bottle of gas in the box and that all helps to make them that few quid cheaper.