its a sealy SP 130What welder is it? It’s impossible to answer your question properly without knowing but if your machine is gasless only then it’s likely to be a small one and probably not up to welding 6mm anyway.
I may have got the thickness wrong its angle iron ill measure tomorrow whats the best size wire?Your not really gonna be able to do that 130amp on its best day is 4mm capability
What are you trying to weld?
Yes, it does.Does flux core come in different thicknesses?